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From: willownest <willownest@thegrid.net>
Date: Thu, 06 May 1999
Subject: Carbon build-up

Ben and group, If you are removing the head to replace the head gasket for carbon build-up, why not just remove the carbon? Ether way it still isn't cheap.

To reverse carbon build-up is virtually impossible. The last engine that I had in my race car was from a wreaked car with 200k on it. It had carbon in it so I did some tests with different chemical additives and fuel injector cleaners to see if anything would work. End result is that it was only fed chevron premium, after one race a large chunk of carbon broke loose and hung #3 exhaust vale open (just slightly). It took about a week to get it back. When I rebuilt it you could see that the piston on the intake valve side was clean, for about 1/4 inch and there was a clean area on ether side of the intake valve (just a sliver). That took 20k to accomplish.

End result is that carbon is carbon, it's hard and it's there. The only real way to remove it is manually. So we do what we can in the mean time. David Uhyrek Shop Foreman/Tech., European Motorsport, Chico Ca., EMSPORT.COM BMW CCA member & Club Racing member http://www.thegrid.net/willownest/Davids320iBMW.htm

From: "Jack Roberts" <j.b.roberts@worldnet.att.net>
Date: Thu, 6 May 1999
Subject: Carbon buildup I seem to recall reading in the "BMW Enthusiast's Companion" that the solution for carbon buildup in a 320i is to replace the head gasket with a thicker one. Is anyone familiar with this solution? And if this were done, would it help to correct previous carbon buildup? Or is this a case of "what's done is done"?

Hi Ben/everyone,

I don't understand the logic of this statement. If one is going to go to the trouble to remove the head in order to replace the head gasket why not just clean out the carbon deposits at the same time. No competent mechanic should do otherwise, IMO. I suppose this could be a cure for an owner encumbered with "little old lady" (no sexist implication intended) driving habits who refuses to use their BMW in the manner for which it were intended. (I just hate being so damn PC all the time;^))

Cheers, Jack

From: casey@adra.com
To: LLAU5@MFS03.CC.MONASH.EDU.AU

LEON,

Have them check the WARM-UP REGULATOR specificly. To do that the fuel pressure and control pressure will have to be monitored as the engine goes from (winter) cold to operating temperature. They may have to pack ice around the warm-up regulator for a few minutes to get it down that cold. The (main) fuel pressure should be aprox. 70psi, the control pressure should go from aprox. 10psi (cold) to aprox. 55psi at operating temperature. The low control pressure makes the air/fuel mixture richer for cold engine starting/running. As the engine/warm-up regulator warms up, the control pressure increases and leans the air/fuel mixture back to normal.

Other things to make sure are done.

Check/set/clean or replace: thermo time switch (elec. on/off - for cold start valve) cold start valve (squirting fuel) aux. air valve (opening and closing) thermo warm-up switch (elec. on/off - for frequentcy valve) WOT* switch (elec. on/off - also for frequentcy valve) frequentcy valve (should be buzzing) warm-up regulator (control pressure) fuel injectors (opening at aprox. 54psi, no dripping, good spray pattern, etc.) fuel filter (fuel pressure/volume) oxygen sensor CO (fuel/air mixture) * : WOT - Wide-Open-Throttle, only works above a certain (~3000) R.P.M.

Also: ignition coil (resistants), cap, rotor (carbon build up), spark plugs (condition and gap), spark plug wires (resistants, arking, age, etc.)

Good luck, Shawn... '83 BMW 320is (E21) BMW CCA Member - Boston Chapter

From: casey@adra.com
Subject: Compression Test

PROCEDURE: Beg, borrow, (don't steal) or bye a GOOD compression tester. Screw in type.

DRY TEST:

Remove the fuel pump relay. (the big black one)
Start the engine and let it run out of gas.
After the engine has coold down, remove ALL the spark plugs.
Remove the coil wire from the coil.
Turn the engine over 10-15 seconds with the throttle wide open.
Screw the Tester into cylinder #1 spark plug hole.
Hold the throttle WIDE open and turn the engine over untill the guage stops climbing plus 3 seconds. (Note: count how many seconds TOTAL this takes)
Write down #1 cylinder reading. (150-130 psi good, less than that bad).
Repeat this for cylinders #2, #3, and #4. (wide open throttle, same amount of time).

WET TEST:

Now, put approximatly 1 teaspoon of motor oil in to cylinder #1 thru the spark plug hole. Use a long rubber tube and get it in to the far side wall so it will run from the high side of the pistion to the low side, covering the rings.
Turn the engine over aprox.5 seconds with the throttle wide open.
Repeat steps 6) thru 8) above.
Repeat steps 1 & 2 for/and step 9) above.

Relpace spark plugs (check gap), coil wire and fuel pump relay.Turn ignition key from OFF to RUN (not start) several times to prime fuel system. Start engine, let it warm up aprox. 2 minutes the go for a GOOD ride. Return to home base and after the engine has coold down, remove ALL the spark plugs and check/clean (from the oil that was put in the cylinders).

From: "Brett Anderson" <go.to.my.site@to.email.me>
Date: Fri, 1 Jan 1999
Subject: 320i: Fuel pump location?

When you removed the back seat you should have seen two metal covers, one on each side of the car. The fuel pump is accessed by removing the cover on the right side of the car, the pump is inside the tank. Remove the cover from the floor, disconnect the hoses and wiring from the pump and sender assembly, remove the 4 8 mm nuts securing the fuel sender and lift it out, then twist the remaining assembly counter clockwise to remove it.

As an owner of 2 present and 1 retired K-jet FI car in the past 10 years. I have spent a lot of time dealing with these problems. I will say that ,in my opinion, the number 1 (numero uno, without a doubt, no question about it ...) problem is vacuum leaks. It only takes a very small leak to cause hard cold and warm starting. I can not stress enough that you really have to look carefully for the vacuum leaks.

This includes:

the PCV hose(s) (must not have cracks and must fit tight on both ends, usually they soak up oil and balloon where they connect to the valve cover) Most people just assume that they are tight enough...not true. Replacement of the this hose pretty much corrected a hot start problem on my '79 320i.
the hoses to and from the aux air (slide) valve. These hoses harden up and although they look ok they will no longer seal well (made worse in really cold weather where the metal nipples contract and the hose is hard as a brick and therefore starts leaking since it can't contract enough to hold on to the nipple).
For '79 and earlier 320i's the hose from the EGR valve to the bottom of the intake manifold. Although it is some different type of rubber I've had one crack.
Intake hose (i.e. the hose from the air flow meter to throttle body).Again these crack and the cracks are not obvious. (problem I had on my L-jet 528i)
Other vacuum lines (including the ones to the charcoal canister)
The injector o-ring seals (This one is a real killer since the leak is on the engine side of the throttle where there is a lot of vacuum to suck air in). This problem killed my Volvo for a few weeks this winter until I figured out what was wrong. The o-rings looked great but the starting problem when away completely when I replaced them.

One thing I've found is that if you do fix some vacuum leaks then you maybe able to lean out the idle mixture and the car will usually run better overall in terms of midrange torque, emissions, and gas mileage. The other common problems are incorrect mixture adjustment, cold-start injector dead or not working, dying main fuel pump or dead in-tank pump (low pressure), bad control pressure regulator (usually stuck in the warm, high pressure/lean condition) and bad ignition system condition (i.e. the car is in need of a tune up). There are other cases such as bad injectors (Try some Techtron if you think this is your problem) and bad fuel distributors (usually caused by water in the fuel) however I've seen a K-jet car run decent with injectors that had poor spray patterns and opened at the wrong pressures (i.e my Volvo with 160K miles). My Volvo also suffered from so much crap (blowby etc) on the air flow flap and linkage that it would stick once in a while. A can of gumout loosened up everything nicely. Regarding ignition, if the car idles too fast when warm but the ign timing and fuel mixture adj is correct and you need to crank open the idle screw to keep the car running when cold check that the vacuum retard system is working correctly (i.e connected). It seems that on cars as old as ours that people just yank out stuff assuming that it is useless emissions stuff when it really does have a purpose other than emissions and it helps the car run better. Concerning the hard starting problem on the late 320i's (80-83) I might be able to help you. If you find the car starts fine in cold weather but starts not wanting to start in warm to hot weather (car cranks, sputters a bunch and then finally catches after 15-60 seconds) your warm up regulator is out of adjustment. The cure for my car was to adjust the warm up regulator to approximately .3 bar lower than the recommended pressure when the car is cold. I had this fix performed by a guy that used to work at Hardy and Beck and had to deal with these cars when they wouldn't start in hot weather. This is when they were brand new. BMW came out with an update kit (warm start kit) that helps, but not all cars were equipted with it. All it really is a lead that causes the cold start injector to fire every time the car is cranked, reguardless of tempurature. This can be accomplished without the kit, but I don't know how (it was done to my car but I never checked to see how). In my case this helped but didn't cure it, it still needed the warm up regulator adjusted.

I should note the second time that I had the regulator adjusted it was at stock pressure and the car wouldn't start without cranking it over for about 30 seconds. It took dropping the pressure in the warm up regulator from 1.8 bar at 70F to 1.5 bar at 70F to make it start properly. Now a question. Does anyone know how the damm brake pad sensor light functions? I had to replace my pads (the little light told me so) and put in a new sensor, and guess what, the damm light didn't go off. Disconected the sensor and the light still stayed on. I have heard there is a relay on the light, does anyone know?

Thanks Cary McReynolds Hard Starting

My ’83 320i spontaneously died on me. It started fine when I left for work, but after I filled up with gas it refused to start. It turned over just fine, but simply refused to fire. It seemed like no gas was getting into the engine. I started thinking it was a clogged or frozen fuel line, filter, or maybe a dead fuel pump. But I overlooked the simplest solution. There is a separate fuse for the fuel pump in the lower left corner of the fuse box. This fuse may be blown, or it might just have dirty contacts. When we replaced my old fuel pump fuse with the one from the rear window defroster, the car fired right up. Unfortunately, it took a AAA call and an hour and a half wait to find this out! A few days later I picked up the April ’99 Bimmer magazine. The final tech Q&A letter in this issue’s column addresses this exact problem. The solution they suggest is also exactly this. I wish I’d bought the magazine a week earlier. I’ve learned the hard way to always check the easy fixes before assuming it’s something more serious.

Justin Hughes

From: Cary D Mc Reynolds, cary@OREGON.UOREGON.EDU
Sent: 3/18/97
Subject: Possible Hard Starting Solution & A question

Concerning the hard starting problem on the late 320i's (80-83) I might be able to help you. If you find the car starts fine in cold weather but starts not wanting to start in warm to hot weather (car cranks, sputters a bunch and then finally catches after 15-60 seconds) your warm up regulator is out of adjustment. The cure for my car was to adjust the warm up regulator to approximately .3 bar lower than the recommended pressure when the car is cold. I had this fix performed by a guy that used to work at Hardy and Beck and had to deal with these cars when they wouldn't start in hot weather. This is when they were brand new. BMW came out with an update kit (warm start kit) that helps, but not all cars were equipted with it. All it really is a lead that causes the cold start injector to fire every time the car is cranked, reguardless of tempurature. This can be accomplished without the kit, but I don't know how (it was done to my car but I never checked to see how). In my case this helped but didn't cure it, it still needed the warm up regulator adjusted.

Thanks Cary McReynolds

From: Walter G. Bariel, barie@diamond.nb.net
Sent: 3/19/97
Subject: Hard Starting (long)

This includes:

the PCV hose(s) (must not have cracks and must fit tight on both ends, usually they soak up oil and balloon where they connect to the valve cover) Most people just assume that they are tight enough...not true. Replacement of the this hose pretty much corrected a hot start problem on my '79 320i.
the hoses to and from the aux air (slide) valve. These hoses harden upand although they look ok they will no longer seal well (made worse in really cold weather where the metal nipples contract and the hose is hard as a brick and therefore starts leaking since it can't contract enough to hold on to the nipple).
For '79 and earlier 320i's the hose from the EGR valve to the bottom of the intake manifold. Although it is some different type of rubber I've had one crack.
Intake hose (i.e. the hose from the air flow meter to throttle body). Again these crack and the cracks are not obvious. (problem I had on my L-jet 528i)
Other vacuum lines (including the ones to the charcoal canister)
The injector o-ring seals (This one is a real killer since the leak is on the engine side of the throttle where there is a lot of vacuum to suck air in). This problem killed my Volvo for a few weeks this winter until I figured out what was wrong. The o-rings looked great but the starting problem when away completely when I replaced them.

From: David Sie, DavidS

@colorbus.com
Sent: 4/8/97
Subject: warm start troubles/reverse lights

hi all,

1st let me say what a wonderful thing this digest is. ok, i have a '83 320i. had it for about 9 months, love it. got a couple problems, tho. recently, every now and then, i go to start the car and turn the key and just hear a -click-, and the alternator light (the circle w/ dashes around it, right?!?) goes on. but i just try a few more times and it starts. is my starter about to give out? if so, can a modest do-it-yourselfer fix it? also, my car definitely does not like warm weather! last summer, i tried to locate its starting problem, to no avail. it was great all winter, but whenever it's warm out, sometimes it just doesn't "catch". or it will start, struggling with low idling (~500), and sputter out. i've replaced the cold start valve (probably unnecessary), and checked the aux air valve. any ideas? and has anybody had to fix their reverse lights? mine never come on, and i think the problem is up in the transmission with that switch (??)...

Hi Chris...

More than likely the starter solenoid is dying. It's close enough to the engine to suffer heat damage! When it's cold it functions fine, when it heats up... click.click... click wait 15-60 minutes and is starts fine. Over time it will get more and more frustrating to diagnose as the problem makes you replace everything else! ;-) My car had the same problem! and the first time around I spent too much for a whole starter!! A new solenoid is only about $40... As for the reverse lights not coming on. When you shift into reverse, a lever or something hits the switch. The swith has an aluminum plunger and wears out over time (as does the lever that hits it)... follow the wire and remove the switch.

You can get at the switch from the driver side from top of engine... just follow the tranny bell housing down and it's just barely out of sight on top (i have an 83 too)... you'll need a 14mm spanner... After you've pulled the switch and tested it, if it still works, put it back without the washer. That should give it enough reach to overcome the worn out plunger... If that doesn't work, time to buy another...

Happy Motoring... David S DavidS@colorbus.com Cmonkey@ix.netcom.com Orange CA 82 320is 1.8L growing up to 2.2L

Date: Tue, 27 Jan 1998
From: Arne Berglund <e21graymarket@home.net>
Subject: Idle problems

When people post about idle problems, one of the first things mentioned is to check for vacuum leaks. DO NOT overlook this step. As my 323i has had a 'hunting' idle when cold since I got it, I have been reading all the posts concerning this problem. Yes, I checked the little vacuum hoses, looked good. But don't forget the big ones. I found that the hose from the throttle by-pass valve (or additional air slide) was swelled up so much that it fell off when I started to loosen the hose clamp to replace it. After all, it was 16 years old. After replacing that hose and the 3 similar sized ones from the bellows to the valve cover and air slide, and resetting the idle speed my problem was solved. I am sure that US 320i's have similar hoses. Because they're so large (3/4" ID), many don't think of them as vacuum hoses so we ignore them. Considering the age of our cars, we should consider replacing these types of things as a matter of cource.

Arne Berglund 1981 323i 1992 K75RT

From: Cary McReynolds, cary@OREGON.UOREGON.EDU Sent: 7/7/96
Subject: Two Possible Causes of Misfires at light throttle. Just thought I would let you all in on a couple of things that can cause the late 320i to miss under light throttle from about 1200-2500 rpms. The first is a combination of to much timing advance and a lean mixture. Backing off the timing a couple of degrees and a slight clockwise turn of the mixture screw will cure it. Another way to deal with the timing is to pull off the plug near the bottom of the distributor, turn the motor over by hand until you see the posts (there are two on opposite sides of the distributor) that hold the advance springs and bend those posts out towards the exterior of the distributor. This will cause the mechanical advance to not come in as quickly, help get rid of the trace ping at 2700-3000 and keep the motor from feeling slugish on the bottom end (like happens if you just back the timing off).

The second is valve adjustment. For some reason late 320is are very sensative to valve adjustment. Make sure all the valves are set equally at a tight .007/ loose .006. Remember when setting the valves to make sure the piston is at TDC on the valves you are adjusting. This occurs when the cam lobes are both pointing down equally (If you were to draw an imaginary line through the motor the intake and exhaust lobes would be split evenly through the line). Make sure to rotate the motor the proper direction when doing this and start at cyl 1 then 3, then 4, then 2.

Hope this might help anyone that is suffering from a light throttle miss. I know that I have had this happen a few times and these have always been the problem.

From: "Laurence G. Hoffman" <104541.344@compuserve.com>
Date: Wed, 1 May 1996
Subject: 320i Plug Wires / Improve spark energy & detonation at 2500-3000 rpm

Hi Russ,

I doubt a "high performance" ignition system will make much difference. The lack of the "hi perf" system is not what's causing the detonation. I don't think high performance plug wires will make much difference. People who have spent a bunch on plug wires will probably disagree. My favorite wires are the Accel yellow wires. I can make 'em any length I want & I like the yellow color. If your wires, cap & rotor really have 56K on 'em, replacement may make a big difference. Maybe not. I'd replace 'em. The cap & rotor will definitely be worn. The wires could have broken down, but my experience is that wires last a long time. As a rule, I replace them every 2 to 5 years. Stick with radio noise suppressive wires, if you're concerned. Checking the ignition timing with a lite is a good idea. Also check the vacuum advance hoses & connections & all the rest of the vaccum lines. Run a can or two of carb/injector cleaner through the gas. Replace the plugs (in that order).

For what it's worth, that's my prescription.

Larry Hoffman, 82 323i

From: Cary McReynolds, cary@OREGON.UOREGON.EDU
Sent: 7/7/96
Subject: Two Possible Causes of Misfires at light throttle.

Just thought I would let you all in on a couple of things that can cause the late 320i to miss under light throttle from about 1200-2500 rpms. The first is a combination of to much timing advance and a lean mixture. Backing off the timing a couple of degrees and a slight clockwise turn of the mixture screw will cure it. Another way to deal with the timing is to pull off the plug near the bottom of the distributor, turn the motor over by hand until you see the posts (there are two on opposite sides of the distributor) that hold the advance springs and bend those posts out towards the exterior of the distributor. This will cause the mechanical advance to not come in as quickly, help get rid of the trace ping at 2700-3000 and keep the motor from feeling slugish on the bottom end (like happens if you just back the timing off). The second is valve adjustment. For some reason late 320is are very sensative to valve adjustment. Make sure all the valves are set equally at a tight .007/ loose .006. Remember when setting the valves to make sure the piston is at TDC on the valves you are adjusting. This occurs when the cam lobes are both pointing down equally (If you were to draw an imaginary line through the motor the intake and exhaust lobes would be split evenly through the line). Make sure to rotate the motor the proper direction when doing this and start at cyl 1 then 3, then 4, then 2.

Hope this might help anyone that is suffering from a light throttle miss. I know that I have had this happen a few times and these have always been the problem. Cary McReynolds 82 320tii 78 320i

From: Top End Performance, TEPSTEVE@gnn.com (Steve Nelson)
Sent: 10/10/96
Subject: Engine Pinging ???

Engine pinging in its more technical term is called Detonation or Pre-Ignition. It is when the fuel in the cylinder fires before it is supposed to. It is a bad thing. Get it fixed before you end up with nice big holes in your pistons or burn up a valve. It is usually caused by, as your friends suggested, too low an octane fuel, or ignition timing that is too far advanced. It can also be caused by an engine that is overheating or has excessive carbon buildup in the combustion chambers. The first thing to do is to switch to a premium grade of gas. 92 or 93 octane and see how it is. Also have your ignition timing checked and put back to spec. We have found that it is no problem to run an extra 2-3 degrees advance over stock as long as you run good gas.If good gas and proper ignition timing do not cure the problem and the car is not overheating excessively have the fuel delivery checked. A lean condition will cause the problem also, but if it is lean enough to cause detonation the car should be overheating as well and have a general serious lack of power under acceleration. Steve Top-End Performance

From: William Bradley, wmbst3+@pitt.edu
Sent: 8/7/96
Subject: Tuning K-jetronic w/O2 sensor

Hi. I have a fairly high mileage (200K) 320i that I am trying to bring up to reliable shape. It has a definite hesitation in engine acceleration during the very first part of throttle travel. This occurs when the car is both warm and cold. It also does not like to idle much below about 1200 RPM . I have tried adjusting the idle with the airflow screw on the intake manifold and the engine will die below about 1000RPM. Other than that, the engine seems to run smoothly. If you want to tune the K-jet with O2 sensor ('80-'83 320i) but don't have the dwell meter for it, you can use the O2 sensor to set the base mixture pretty well.

The frequency valve is very good at leaning out the mixture and can only enrich a little bit (that's why it's kicked off by the little microswitch at full throttle) so you want to set the base mixture rich. Get a good (2-10Mohm impedence) voltmeter, disconnect the oxygen sensor (this will put it in default mode, about 52 degrees dwell I beleive) and adjust the mixture until the output of the oxygen sensor reads between 0.75V and about 0.95V at 2500 or so rpm (don't set it at idle, the sensor won't give coorect readings if it is too cold, i.e. <800C) when you reconnect the sensor, you should read between 0.5V-0.75V from the sensor which is the reading for a correct mixture. (lower voltage is lean, higher voltage is rich).

If you do have a dwell meter there should be a "test connector" somewhere to adjust it. I know where it is on my Volvo 240, but haven't looked for it on the BMW yet.

Bill '80 320i 170K miles '80 242DL 192K miles

From: reb@oix.com
Sent: 02/07
Subject: Surging idle-1980 320i

Friends, After repeatedly adjusting the rocker arm locknuts, I broke the vacuum hose coming out of the valve cover. It has been an eventful day trying to replace it, with success it was done.

Yes this is a common occurance on 320i's with the M10B18 (your 320 does havean O2 sensor ..right?)

Now I am experiencing a very bad surging problem, the idle dips very low to 5000 rpm up to 1500 rpm upon You do mean 500 RPM's don't you! start up. After a little gas it will level out.

I can't seem to be able to adjust the idle to 1000rpm. I have to set the idle to 1200rpm to keep this five speed from stalling.All the hoses leading from the valve cover and the connecting "Tee" appears to be intact. Did I upset a delicate balance? Sounds like your mixture needs adjusting, if you engine has an O2 sensor and it is functioning, there should be a little valve under the intake manifold with an electrical connection on it, it should be buzzing of an on like crazy (O2 sensor trying to regulate) This may or may not be working depending on the state of the O2 sensor and the valve etc. It was not a good system.

Anyway, what you need is a long 3mm hex that will fit into the air flow sensor, but before you start adjusting take the airflow sensor hood off and take a look at the sensor plate (K-Jetronic fuel injection) make sure it is not bent or stuck....also check the underside of the bellows (if the hood and bellows have never been replaced it could be cracked or have a hole in it, could have been made worse when you put the crankcase breather hose on it) if it has a hole, you will have to replace it. If all is ok then with the 3mm hex insert into small hole in AFS and locate the hex inside (make sure it fits and you can turn the hex in the sensor, you may want to do this with the hood off before you start the engine. Make sure you remember your starting point when you put the hex (Allen wrench) in.) Start car and turn hex half a turn from the point it was with the surging (left or right your choice, i cannot tell whether it is lean or rich) watch the results one way will make the condition better, the other way will probably make it stall and not start again (if this happens, turn hex opposite way one full turn and start car) adjust in 1/4 turn increments until your idle is stable, you will also need to adjust the air volume on the side of the throttle flap as well (fairly big recessed flat head screw type thing) again 1/4 to 1/2 turn increments in or out. If you want to get the mixture spot on you will have to take it to a shop with a CO meter and get it adjusted properly.

Hope this helps and is not to confusing

Would the cold start valve be the culprit or perhaps the air flow meter? Cold start valve...possible (air slide or injector?) air slide ...just clamp off the pipe leading to the engine, if it is the problem this will tell you, injector ..remove plug. Was it working ok before you adjusted the valves etc.?

Hope above helps!

From: wmbst3 @pitt.edu (William M Bradley)

If you want to tune the K-jet with O2 sensor ('80-'83 320i) but don't have the dwell meter for it, you can use the O2 sensor to set the base mixture pretty well. The frequency valve is very good at leaning out the mixture and can only enrich a little bit (that's why it's kicked off by the little microswitch at full throttle) so you want to set the base mixture rich. Get a good (2-10Mohm impedence) voltmeter, disconnect the oxygen sensor (this will put it in default mode, about 52 degrees dwell I beleive) and adjust the mixture until the output of the oxygen sensor reads between 0.75V and about 0.95V at 2500 or so rpm (don't set it at idle, the sensor won't give coorect readings if it is too cold, i.e. <800C) when you reconnect the sensor, you should read between 0.5V-0.75V from the sensor which is the reading for a correct mixture. (lower voltage is lean, higher voltage is rich).

If you do have a dwell meter there should be a "test connector" somewhere to adjust it. I know where it is on my Volvo 240, but haven't looked for it on the BMW yet.

Bill '80 320i 170K miles '80 242DL 192K miles

From: reb@oix.com
Sent: 02/07
Subject: Surging idle-1980 320i

Friends, After repeatedly adjusting the rocker arm locknuts, I broke the vacuum hose coming out of the valve cover. It has been an eventful day trying to replace it, with success it was done.

Yes this is a common occurance on 320i's with the M10B18 (your 320 does havean O2 sensor ..right?)

Now I am experiencing a very bad surging problem, the idle dips very low to 5000 rpm up to 1500 rpm upon You do mean 500 RPM's don't you! start up. After a little gas it will level out.

Hope this helps and is not to confusing

Hope above helps!

From: Shawn Casey, casey@adra.com
Sent: 1/20/97
Subject: pressure regulator/new seats

I have a problem with erratic idling of 100 rpm on my 83, 320i. The problem only exists after the car has warmed up...

Rich, This sounds like a classic bad oxygen sensor problem. Unplug the oxygen sensor wire and see if the idle settles down. If it does, get a new oxygen sensor and have the CO checked/set.

I replaced the OX sensor and the problem improved a little bit but I still have an idle that is a little erratic.

If not, it could be a fuel filter, pre-pump, main-pump or control pressure (frequentcy valve or warm-up regulator) problem.

I also replaced the fuel filter and the fuel pump. The old pump was going bad and the new pump made a big improvement, for a little while. When I first replaced the pump you couldn't hear the new pump inside while the car was running, the old one was pretty loud. Now the pump seems to be a making more noise and is fluxuating with the erratic idle. Could this be due to not enough current getting to the pump from the electrical system. The pump labors more with the headlights on, wipers ect.How do I test if the freq valve or the warmup regulator are bad?

Note: The control pressure should go from aprox. 10psi (at very cold air temps) to aprox. 55psi at engine operating temperature. As for the "pressure regulator" (it is built into the fuel distributor) can easily be checked and adjusted by changing washer type shims. The pressure in the line going to the fuel distributor should be aprox. 70psi.

How do I test this?

The Bosch "Fuel Injection and Engine Management" manual covers all this and everything else you want to know about the K-Jetronics F.I. system.

I guess i should get the book. Any more info on how to make the engine rum smoother would be greatly appreciated, tips, books ect.

Todd Davis

From: casey@adra.com

Philip,

When you say "I broke the vacuum hose coming out of the valve cover" do you mean the crank case breather hose? It is about 3/4" diameter and connects to a nipple right on the valve cover? (Just how did you "fix" it?) If so check ALL the hoses that branch off that hose and see if one of those other hoses came off or is loose. Note that one of the hoses goes into the large rubber boot that goes between the flow meter and the intake manifold and is very difficult to follow and get a good look at. You my need a flashlight and mirror.

Also check the following for air leaks: Valve cover/gasket (check for tight seal all the way around) Oil filler cap (on tight) Oil dip stick (pushed in good and tight) ALL vacuum hoses, small and large Do a test on the cold start "valve", make sure it is opening and closing. Do a test on the cold start "injector", make sure it sprays and is not leaking. The air flow meter should not have changed if you have not touched it.

Good luck, Shawn... '83 BMW 320is BMW CCA Member - Boston Chapter

From: reb@oix.com
Date: Tue, 6 Feb 1996
Subject: Surging idle-1980 320i

Friends, After repeatedly adjusting the rocker arm locknuts, I broke the vacuum hose coming out of the valve cover. It has been an eventful day trying to replace it, with success it was done.

Yes this is a common occurance on 320i's with the M10B18 (your 320 does have an O2 sensor ..right?)

Now I am experiencing a very bad surging problem, the idle dips very low to 5000 rpm up to 1500 rpm upon You do mean 500 RPM's don't you!

Start up. After a little gas it will level out. I can't seem to be able to adjust the idle to 1000rpm. I have to set the idle to 1200rpm to keep this five speed from stalling.All the hoses leading from the valve cover and the connecting "Tee" appears to be intact. Did I upset a delicate balance? Sounds like your mixture needs adjusting, if you engine has an O2 sensor and it is functioning, there should be a little valve under the intake manifold with an electrical connection on it, it should be buzzing of an on like crazy (O2 sensor trying to regulate) This may or may not be working depending on the state of the O2 sensor and the valve etc. It was not a good system. Anyway, what you need is a long 3mm hex that will fit into the air flow sensor, but before you start adjusting take the airflow sensor hood off and take a look at the sensor plate (K-Jetronic fuel injection) make sure it is not bent or stuck....also check the underside of the bellows (if the hood and bellows have never been replaced it could be cracked or have a hole in it, could have been made worse when you put the crankcase breather hose on it) if it has a hole, you will have to replace it. If all is ok then with the 3mm hex insert into small hole in AFS and locate the hex inside (make sure it fits and you can turn the hex in the sensor, you may want to do this with the hood off before you start the engine. Make sure you remember your starting point when you put the hex (Allen wrench) in.) Start car and turn hex half a turn from the point it was with the surging (left or right your choice, i cannot tell whether it is lean or rich) watch the results one way will make the condition better, the other way will probably make it stall and not start again (if this happens, turn hex opposite way one full turn and start car) adjust in 1/4 turn increments until your idle is stable, you will also need to adjust the air volume on the side of the throttle flap as well (fairly big recessed flat head screw type thing) again 1/4 to 1/2 turn increments in or out. If you want to get the mixture spot on you will have to take it to a shop with a CO meter and get it adjusted properly.

Hope this helps and is not to confusing

Would the cold start valve be the culprit or perhaps the air flow meter?. Cold start valve...possible (air slide or injector?) air slide ...just clamp off the pipe leading to the engine, if it is the problem this will tell you, injector ..remove plug. Was it working ok before you adjusted the valves etc.?

Regards, REB

From: John Richardson, DPXG07A@prodigy.com
Sent: 5/27/96
Subject: Timing chain

Bob, someone has changed your chain set-up. YOur car came stock with a single row. I have two 80 320's that I have rebuilt and added the double row chains per recommendation of some local tuners. Some folks will tell you that the two row chain adds mass, and others tell me it is stronger....6 to one half a dozen to the other!

Anyway, I have successfully rebuilt these engines to 2.0 ltr by simply changing the pistons to the 9.3 : 1 euro 320 pistons and using a 77-79 2.0 ltr crank. It is a good combination. The last motor I did runs about 225 on the compression tester so I know it is getting more than the 9.3 : 1 ratio. This is due to the displacement of the cyl. head on the 1.8 head. You have to be careful to run "good" gas with this ratio as it will spark knock. Go for it!

From: Cary McReynolds, cary@OREGON.UOREGON.EDU
Sent: 7/7/96
Subject: Two Possible Causes of Misfires at light throttle.

Hope this might help anyone that is suffering from a light throttle miss. I know that I have had this happen a few times and these have always been the problem.