E30 Running Rich

[ryanreddE30]

Hey what’s up guys, I have a 1987 325is and i am having problems with it running rich. The car will idle a little bit rough and sometimes will almost die when I give it gas at idle. When I give it gas, the idle will drop and then rev back up. As soon as i start driving i will get a check engine light and it smells horrible. I checked for intake vaccuum leaks and didn’t find anything. The car pulls hard and feels strong. Anything helps!

[jclausen]

I wonder if the fuel pressure regulator is faulty if you remove the vaccum hose on it and there is gas then the diaphragm is blown allowing the fuel pressure to sky rocket and pushing excess fuel thru the injector

[ryanreddE30]

That was kind of what I was leaning towards. Thanks for the advice, i’ll check that out!

[bluptgm3]

You should be able to pull fault codes either from under hood connector or by accomplishing a ‘stomp test’, which allows pulling code from the instrument cluster.


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[richardodn]

As suggested, check the fuel pressure. Also pull the vacuum hose from the regulator and see if it's dumping fuel into the intake. However it's still likely a vacuum leak. The description of hesitation off idle and then pulling fine when revs climb is almost always a vacuum leak.

[agisthos]

If you pull the vacuum hose on the fuel pressure regulator, what is supposed to happen if running correctly? My car does nothing when i pull it, no change in idle or anything. I'm not sure if that is normal.

[jclausen]

We're looking for gas because that means the diaphragm in the fuel pressure regulator is blown and instead of fuel pressure being. 45 psi it's like 80 psi and gas can also be sucked thru the vacuum hose