1991 325i m20 help, madison

[Boris3]

Ok time to go back to the beginning. Car was running better before you did all the tune up things, correct? Was it sputtering at all before you did anything to it?

So it's something you did.

Basics:

-the plug wires are connected correctly to the proper holes on the distributor cap and to the proper cylinders.

-you replaced the rotor ; rotor was ok

-you removed the metal screw on pieces on the ends of the spark plugs

-You made sure timing was correct (nothing jumped a tooth when you were installing the belt, tensioner was changed)

[Boris3]

Basics cont:

-any hoses removed, reattached improperly when removing the valve cover, or opening the air box to replace the filter (the wire plug to the air box unconnected/ reconnected), metal elbows still tight on the throttle body after working on the air box,

-main accordion air hose to throttle body not cracked in the accordion seams (old hose could crack when opening the air box to replace the filter)

[B C]

If you can have the car off the road for a couple days I can inspect, clean, test and adjust the airflow meter free of charge

[cpandrewschmidt]

Thanks Boris, 

I'll double check everything again, i think you're right i'll just have to take things apart again.  I got the Bavauto performance wires.  I was told not to remove caps from the plugs for those wires.  The wires click onto the plugs so I think they're on there correct.  I have also tried it with the caps off and it didn't make a difference.  

Snap - that would be great, i'd love a second set of eyes.  I'm sure once I figure it out it'll be something stupid.  The car isn't my daily driver so it's just sitting in the garage right now until i can figure it out.  I can come home over lunch or am generally free after about 5:30pm.

[B C]

Im in New Berlin and unable to make it out that way because of my idiotic schedule as of late so you could mail it to me and I could mail it back

[cpandrewschmidt]

Update - Ran a homemade smoke test with a compressor and paint can trick.  Worked like charm.  One very small vaccuum leak on the bottom of the hose that attaches to the valve cover.  Took it off and it basically snapped apart it was so brittle.  Ordered a new one.  

While waiting for that to come in I popped the valve cover and adjusted the valves.  There wasn't 1 that I could get the feeler under, so they were pretty tight.  I adjusted those to the best of my ability.  Definitely a finky job.  I don't feel like I did as good as I could have, anyway...

Hose came in today and put it back on over lunch.  Fired it up.  Seemed to still do the same thing initially but settled down after a little bit.  DME adjusting itself??  I let it idle for 5 mins before working up the courage to take it out.  Drove it for 10 mins around the subdivision and a road up to 45 mph.  Knock on wood it performed well.  Going to put it through some more rigorous driving tonight.  

I did notice my idle dropped to the 800 ish rpm range, where before it was about 1100 rpm.  So, I think that's a good thing too.  Valves still seem to tick a bit, there's probably one or two that aren't quite right.

[Doorman]

Good deal brotha!!!

If you could, share your homemade smoke machine pictures please?

[jc43089]

I am not sure if the version of Motronic you have adapts like the ECU in the e36 but you should reset it by disconnecting the battery and touching the cables together to clear the ECU and force it to relearn the engine.  On the e36 you have to do this anytime you make a modification and/or fix a problem like that.  I installed a lightweight flywheel in a 328 and it would hardly idle until the ecu was reset, then it relearned and smoothed right out.

[cpandrewschmidt]

Drove it more last night.  Still has some sputtering issues, but not NEARLY as bad.  I at least feel like I can drive it to places.  It smooths out more after its warmed up.  Still might have to take up a couple of your offers to look things over to see if I'm missing anything if you're still willing.  

Looking online it doesn't look like my ECU resets like the e36.  I unplugged the battery last night and am letting it sit all day today.  Will try again tonight.  

As for the smoke test I just modeled it after these two posts.  I put a hole in a soda can and the can fits nicely into the intake hose.  Just tape it and seal it off good before putting smoke into the system.  Dont forget to open the throttle.  

http://www.r3vlimited.com/board/showthread.php?t=292791&page=2&highlight=smoke

http://www.r3vlimited.com/board/showthread.php?t=274418&highlight=smoke

[cpandrewschmidt]

hooked the battery up again and turned on.  Still sputters like before.  Still bad enough that its definitely not right.  I have no idea.  Ugh.  

I'm thinking this still might go back to those Bavauto performance wires and plugs.  I did find one buried topic online of a person having issues with those wires.  

Is there anyone I could meet up with that has an m20 engine that would be willing to let me try their plugs / wires to rule that out?  

Thanks again for every ones help here.  Oh, I did also hook the vacuum test back up and I got 16-17 psi, so that was much improved from before and where it should be.

[jc43089]

Is the vacuum gauge steady?

I have some i wires that are used but worked fine.  I work with a guy from Mount Horeb, he could probably get them to you on Sunday maybe.

[YoungCR]

My new wires came from ECS but I won't be around this weekend. Not sure what brand they are yet. I think I rememeber hearing some issues with Bavauto wires too.

[Boris3]

Sorry to hear it's still not cooperating.

I've got an old set off my 90 325i you can try if anyone is heading Madison way from New Berlin/Milwaukee.

[cpandrewschmidt]

Thanks JC - sent you a message.  I can meet up today after noon or tomorrow if possible to grab those.

[cpandrewschmidt]

Ugh, frustrated.  Changed out the wires (thanks JC) and put in some NKG plugs just in case.  Still getting the same problem.  

Out of ideas

[B C]

Afm

[jc43089]

Snap, what happens with the afm unplugged?  Does it use default safe tables?  That could be a way to test by trying to run it with the afm unplugged.

[Jdesign]

I am in Madison and am more than willing to take a look at your car. I am sure we could get to the bottom of this in a few hours. You should compose a list of everything you swapped out or replaced in attempt to diagnose the problem. Shoot me a text and when you have time, swing by my shop and I can help you get this sorted, like you said, I am sure its something simple.

414.eight52.five943

[cpandrewschmidt]

Thanks guys, you all rock for offering to help like this.  

I've tried unplugging the AFM and the car just stalled and died so I'm not sure it can run without that plugged in, i don't think so.  

I'm going to try cleaning the AFM tonight and moving the track slightly on the electronic sensor like this guy does.  I opened it up and I definitely have two distinguishable spots of wear along the track.   

http://www.r3vlimited.com/board/showthread.php?t=247831

I don't totally understand how the AFM works but this might be it.  The thing I don't understand is does that arm constantly move along the senor pad, or does it only adjust while pressing the throttle?  If it's the later I don't think that'd be my issue because the car sputters even when in idle.  However, if that arm is constantly moving based the other sensor in the air box it'd make sense for the car to sputter when it hits the dead spots along the track.  

Either way, I'll report back tonight!

[jc43089]

When there is more air moving through the afm it opens then flap which is linked to the wiper.  The cross section inside of the afm increases as it opens so it will open in a somewhat linear way through the range of airflow.  The air is based on how far the throttle is open.