Car idle problem with video! kinda long

[pwcadie]

http://www.youtube.com/watch?v=hPxjZZZ90iA

First off its a 1988 325is. Had a rough idle took it to a guy and said the intake manifold gaskets were leaking and some hoses. I replaced the gaskets and random hoses and intake boot. Thought everything was gravy and started the car and sounded like CRAP. Found out only 4 or 5 cylinders were firing. Found out that the connector under the intake manifold was corroded to the point where a wire broke off. Fixed that problem then started the car again and still did the "dip" or stumble. Tried a 173 ecu thinking the ecu was fried, didn't help. NOW for the video part, you see me touch the AFM box which is a m30 swap, I had the cover off and moved the barn door open and it idles perfect, only if i hold it at certain spot. I'm thinking the MAF has crapped out on me. Also the car runs fine when in gear or event just revving it, only problem is the idle. Any help or suggestion would help me out A LOT! Thanks:D

[pwcadie]

bump?

[speedhop]

have you tried o2 sensor or cleaning your icv? simple...but i always forget the simple stuff

could be head gasket, could be vacuum leak. bad idle means lotsa possibilities

[pwcadie]

I did clean the ICV, I checked its resistance and it is working fine. I checked the volts on the connector and one reads the 12v and the others are suppose to be 10v but only one is 10v. I've sprayed about every rubber hose and connection for vacuum leaks and I haven't found any. And the o2 sensor I thought was only used when the car was warm, this happens when its cold and when it warms up.

[BingM3]

I think your car needs Robitussin CF:)

Pour ever 3,000 miles /90 days whichever comes first

Sounds like a leak somwhere, spray starting fluid on all areas of engine while running, if at any moment the idle stabilizes when it sucks it in...then you have a leak there, that's a start.

[pwcadie]

ok well I will try that again and on all parts of the engine.

[rcko]

hey man, onmy 88 it turned out to be the DME ICV idle curcuit was shoot!

On mine I chased this issue by replacing everyting iginition and fuel related included the ICV. Finally I gave up and put in a new DME and bingo.. IT fixed it. Now, I read somwhere that faulty ICV can fry the DME Idle circuit, specially the ones with the penny/washer trick since it send a higher than normal amp load to the DME circuit. So test the DME with a good known ICV.

[pwcadie]

I did change the DME, I followed the Bentley manual and if I remember right the 37 connector is suppose to have a 12v and mine had little to nothing. Another question, if I turn my key but not start the car is the ICV piston suppose to be open or closed? Mine is closed shut, it hums and everything.

[wickedE30]

I think it's your Afm,If it was the dme your idle would be surging up and down from 800-1500 rpm.If you have the origanal afm put it in and try it then.

[pwcadie]

Yeah, I'm starting to think its the AFM. I'm trying to find a working one(got the car with the M30 AFM installed).

[xLibelle]

all in all, you have some work to do.

[pwcadie]

damn, that's not what I want to hear.

[mops]

well, the best way to check for vacum leaks is to measure idle vacum. m20b25 should idle around 35-40kpaa at 800 rpm idle...

crankcase is vented to pvc (i.e. back to intake after tb), so if rings are blown big time then it will idle bad, aswell that implies that it might be getting extra air from eg, under oil cap or other crankcase vacum plumbing piece...

simple test, while idling badly, undo oil cap and notice whether idle quality changes... if not then you got somewhere massive vacum leak or damaged or miscalibrated maf.

it could be stuck injector or bad fpr or few other things, but realistically following bentlyy you should perform few tests and report back so we can point you in some direction...

[pwcadie]

well for an update. I replaced the AFM with a stock one and changed the o2 sensor and the idle problem in the video is fixed. After driving it, it stalled when I pushed the clutch in then put it in neutral (moving). I let it sit when I got to my friends house and then I started the car and died, took a few good seconds to start it and I held my foot on the gas. Got almost home and stalled when I came to a stop sign. Took a good 5-10 secs to restart, got it to run and it also bucks when accelerating. Then when I was in 3rd gear and coasting it slowed down as if I was engine breaking yet I was giving it gas, put the clutch in and then it backfires. Put it in 2nd and drove fine. I think I need to drive it for a bit longer. Still wants to die at idle.....grrr.

[pwcadie]

Oh and I replaced the hoses to the brake booster.