Running poorly

[HybridRaptor]

My M20 runs pretty terrible at idle, the idle stays around 800rpm but it stumbles quite a bit, and smells rich at the exhuast. Even with the engine out of idle it stumbles slightly if kept at a constant rpm.

It has new plugs, new intake boot, the intake manifold gasket was replaced just over a year ago, the valves were adjusted this week with a new gasket and the four rubber plugs.

The AFM seems to read ok with the resistance rising as the flap moves, and the temperature sender is giving a resistance about where it should be (car wasn't dead cold or fully warm, but the value was in between where bentley says for the each)

http://smg.photobucket.com/albums/v463/hhsraptor/Videos/?action=view&current=MVI_1537.flv

The video doesn't really show how rough it is, it's very noticable though.(maybe i'll get a better video)

Any help/suggestions are appreciated.

[jlevie]

Have the ignition wires, rotor, and distributor cap been recently replaced? What mileage do you have on the O2 sensor (if 100k, replace it)? What plugs dis you use?

[HybridRaptor]

Have the ignition wires, rotor, and distributor cap been recently replaced? What mileage do you have on the O2 sensor (if 100k, replace it)? What plugs dis you use?

Have not touched the wires, rotor or cap, the plugs are Bosch Supers. The O2 sensor probably needs to be replaced, but the car runs about the same without it plugged in(maybe a little more rich), and I'm getting about 25mpg combined.

[Republic]

The O2 sensor won't kick in until it reaches a certain temp, until then the comp runs the mixtures.

I had similar issues and had changed pretty much everything before it was resolved. It sounds like you may have a vacuum issue. However, depending on the mileage, you should do the regular maintenance on it, Cap/Rotor, Ignition Coil, Wires and so on.

What does your "stomp" test come back with. Turn the key in the "on" position without starting the car. Stomp on the gas pedal (all the way to the floor) 5x's in 5 seconds or less. Having a 90 325i your "check engine" light should flash once and then proceed to give you subsequent flashes. The codes are given in sets of four. It will play all the codes out and then repeat them when it is done.

See what you come back with. Google "e30 stomp test" - plenty of sites that will give you the fault code definition.

[HybridRaptor]

The code is 1222, which of course is the most fun code to fix. I've looked around for a vacuum leak but havn't been able to find one, the hose from the valvecover to TB is also new.

[jlevie]

Replace the wires, rotor, and distributor cap and install a new OE O2 sensor. Replace the dispstick o-rings and oil filler cap as either can be an intake leak. Check the metal fitting where the ICV and brake booster line attach to the throttle body as they will loosen with time & vibration (JB weld is a good fix). Run a vacuum test on the brake booster to see if it is leaking. Run the fuel pressure & delivery tests documented in the Bentley.

[wagonizzle]

I solved a few problems by adjusting my TPS back to spec. If you haven't checked this, it's free and can't hurt... good luck man.

[pig4bill]

Is there an easy way to get the distributor cap off? The Bentley says remove the fan shroud and the fan. Are there any shortcuts? I don't have the fan wrench.

[bimmerkarl]

I did my cap and rotor the other day without removing the shroud or fan.... and have the marks to prove it. mine still runs a little bumpy at idle though. and it has this weird problem where the idle drops to like 300 rpm and wont rev higher than 2000 for more than a second with your foot all the way down to the floor, plus the instruments go crazy.....one minute later,its gone..... sorry didn't mean to thread jack