Hunting for idle when coasting, VSS related?

[matthugie]

I've been having a hunting for idle issue intermittently as well, been frustrating as shit. Pretty much all new hoses (with a couple exceptions, but smoke tested fine), 3.5" intake and boot (which was tuned for). Concurrently, the car would throw a CEL when redline was hit. The codes were run and there was a MAF code, which, when cleared, made the car run a shit ton better. Though, after some time driving, it comes back.

My current thought is FPR under the intake manifold coming unplugged, but that remains to be corroborated.

[trackjunkie21]

Did a compression today and all cylinders were exactly the same. After 3 cranks they reached 175psi as alldata specified. Here is a picture of the condition of the plugs. What say ye?

[trackjunkie21]

Any links? Would be most appreciated!

[Beej '86 325es]

I've done a lot of reading on Bimmerforums' E36 M3 forum, and it seems like I've read about rough warm idle issues on there somewhere.

[trackjunkie21]

bump =/

[trackjunkie21]

well I had a really loud backfire last time, I went WOT from idle in neutral and it felt like it didn't want to rev up intil 2,500-3,000 when it backfired and then revved freely. tried it again and didn't backfire. hmm.

[trackjunkie21]

I think not, i replaced my 02 sensor three times. And i have brand new spark plugs and coils which were then tested for resistance

[Highway1]

When I got new cats put in I changed my 02 sensor and new spark plugs and my car no longer hunts. I occasionally coast to a stop to test it and every time the rpm is solid.

coincidence

[Beej '86 325es]

Possibly...but man I think we would be throwing codes if it was something that obvious, right?

[trackjunkie21]

A lot of people are telling me that a bad TPS causes similar symptoms to what I have, even thought I tested the TPS which showed .5v at 0% throttle and 4.3V at WOT, with readings fluctuating in between. Could I still have a faulty sensor?

[trackjunkie21]

tested my tps, readings within spec:(

[trackjunkie21]

no, mine idles smooth as silk and never hunts for idle.

I go back to asking about the vacuum hoses. Are they new? or are you all re-using old ones? I used all new hoses. How is the ICV clip where it goes to the intake? I know those are notorious for breaking.
All my vacuum lines along with my ICV are brand new, the clip is brand new and for reassurance, I zip tied it to the manifold so it doesn't back out, there is a bit of oil residue on the manifold from it though

what about the adjustment screw on the throttle body? fiddled with that at all?
I was under the impression that their is no adjustment on the throttlebody.
mine did idle rough with the stock S50 chip but that's pretty much because of the lightweight flywheel. I now have a TRM chip and it's perfect.

Here is a video of me testing the said pin 30. Once the car is on the light appears to look green, it is actually red which tells me there is power at pin 30.

[Beej '86 325es]

I checked power at pin30 on the 02 relay, it's the one closest to the driver correct? First think i start the car, their is power at pin 30.

I suppose it depends on how you mounted your relays. :)
If you mounted them inside E30 M3 harness closeouts like I did, then yes, it's the pin closest to the driver.

[e30rapidic]

So you don't have this problem?

no, mine idles smooth as silk and never hunts for idle.

I go back to asking about the vacuum hoses. Are they new? or are you all re-using old ones? I used all new hoses. How is the ICV clip where it goes to the intake? I know those are notorious for breaking.

what about the adjustment screw on the throttle body? fiddled with that at all?

mine did idle rough with the stock S50 chip but that's pretty much because of the lightweight flywheel. I now have a TRM chip and it's perfect.

[trackjunkie21]

I checked power at pin30 on the 02 relay, it's the one closest to the driver correct? First think i start the car, their is power at pin 30.