Not another rough start/idle/running thread... tried most everything so far

[PEZ2]

If you have original fuel injectors get them serviced or replace them. I am finding lots of old clogged injectors with a 10% complete failure rate in the last 60 I looked at. Just replaced ones in a 90 325i and the caps looked like they were in a tar pit. It wouldn’t hold a cold idle at all and ran just ok.

[82eye]

I have 1991 318IS with a very rough idle. Otherwise car runs great. I have to keep revving engine on stop lights so it won't die. No other running issues. Where should I look first? Spark plugs? Injectors? Idle control valve?

Thanks

vacuum leaks

[bte0001]

I have 1991 318IS with a very rough idle. Otherwise car runs great. I have to keep revving engine on stop lights so it won't die. No other running issues. Where should I look first? Spark plugs? Injectors? Idle control valve?

Thanks

[Lippy]

I recently had misfire issues and it ended up being an injector as well. I decided to replace all of them.

[OSAH racing]

thanks

[82eye]

I am chasing a rough idle that stalls sometimes. What ended up being the problem with yours and how was it fixed?

the answer is two posts above yours.

[OSAH racing]

I am chasing a rough idle that stalls sometimes. What ended up being the problem with yours and how was it fixed?

[BoxE30]

excellent catch.
which ones are you running ?

Not sure of exact ones. The mechanic is a BMW fanatic with a 318is that's pretty done up. Mentioned having a set on hand and I figured while he was in there, may as well upgrade.

[82eye]

Wanted to provide a quick update. Ended up being a faulty injector and a misfire. Upgraded to mustang injectors and it’s good to go.

excellent catch.
which ones are you running ?

[BoxE30]

Wanted to provide a quick update. Ended up being a faulty injector and a misfire. Upgraded to mustang injectors and it’s good to go.

[BoxE30]

The gas leak should definitely be repaired before continuing. Then I'd start by verifying your TPS sensor is adjusted correctly, ensure your engine harness is not corroded and verify your AFM is still good by using a scope at the DME. If your AFM is still the original unit, and not rebuilt, I would consider it bad.

Taking it in finally tomorrow. I can definitely raise this to their attention - thank you!!

[Gregs///M]

The gas leak should definitely be repaired before continuing. Then I'd start by verifying your TPS sensor is adjusted correctly, ensure your engine harness is not corroded and verify your AFM is still good by using a scope at the DME. If your AFM is still the original unit, and not rebuilt, I would consider it bad.

[BoxE30]

Did you verify the wire connection on the passenger side of the firewall is unplugged? It’s accessible from the engine bay and a single wire connection. It needs to be unplugged.

Still wondering what the heck that plug/wire is for but has definitely been unplugged since I’ve owned it. Good tip though

[BoxE30]

check external pump and lines to and from the pump. it's located near the passenger rear tire. it's likely something in there.

Just one internal pump on the ‘91 318is

[ahlem]

Did you verify the wire connection on the passenger side of the firewall is unplugged? It’s accessible from the engine bay and a single wire connection. It needs to be unplugged.