$500 in parts- now have stumbling issue

[Stevie30]

Brian, Check to be sure all your plug wires are seated fully in the distributor cap. I had a nagging problem and I found one wire corroded and not fully seated. Good luck.

[320is4dr]

i know u said it only runs rough when it gets warm but try checking the rotor + cap for cracks (way diff car but) on my 240 back when i had it i had a hairline crack inside the cap and it did kind of the same thing and i thought it was the tps.... try swapping for the old cap if you still have it. (and yes on my 240 it ran fine when it wasnt warm for whatever reason so dont flame my 2cents)

[bimmerboy12]

Time for an update. The problem is still there. I got a stethoscope for detecting air leaks and dragged that thing over every hose, fitting, connection, gasket, etc. and i got nothing. When I pull a hose like the one to the fuel regulator, it sucks air like freakin vacuum cleaner and starts idling really rough. Plug it back in and its back to just idling kind of bad.

Here is a wild thought: I tested the coil and I am getting zero resistance when I should be getting resistance according to my Bentley manual. Therefore, it is not right. Since I replaced the wires, cap and rotor (which were all in pretty bad shape) would the car be more sensitive to the coil being bad/not good? What are the symptoms of a bad coil anyways?
Thanks for all your help guys.
Brian

Most rough idle issues are caused by a vacuum leak. Check all the hoses and orings on the intake side. (There are a bunch of hoses.)

And don't forget that an oil leak on these engines is also a vacuum leak. This means that a bad oring on the dip stick or a leaking valve cover gasket can cause a bad idle.

[twright]

Bad Idle

Most rough idle issues are caused by a vacuum leak. Check all the hoses and orings on the intake side. (There are a bunch of hoses.)

And don't forget that an oil leak on these engines is also a vacuum leak. This means that a bad oring on the dip stick or a leaking valve cover gasket can cause a bad idle.

[clavinZERO]

Try spraying hoses and other possible leak areas with a can of carb cleaner... one at a time. Spray, wait, listen. Nothing? Move to another spot. Spray, wait, listen. If the idle changes, then you have an air leak where you sprayed. I have found a few issues on friends' cars this way.

Just another 2 or 3 cents...

Adjusting the throttle and the AFM need to be done specifically:
The throttle when full closed should have I think .010" of feeler gauge clearance between the butterfly valve inside and the wall of the body itself.

As for the AFM... I believe you need something to read your emissions/mixture and you do it with the o2 sensor disconnected.

Check/wiggle various electronic connectors like on the AFM, etc.

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And... do you have enough/good gas in there? :P

[bimmerboy12]

I changed with a brand new temp coolant sensor, had the issue, put the old one back in, didn't change. Idled fine before the work so the old one is good.

The problem is still very much alive and pissing me off.

[chris328i]

my car does a similar thing. about to change temp sensor.

[Intro]

u get it?

[Intro]

There are monitors from the ecu that checks everything and tells the car how much fuel to give it (you probaly already know this) and because the coolant sensor places such a big role in this and you changed yours, this would be where i would look. If i were you id try to disconect the battery, and then reconect and go through the driving process of resetting all the monitors (not sure if there is one on e30s). This will let the computer learn the the new coolant sensor.

Just throwing my idea out there to try and help.
also make sure the plugs are gapped right.

let us know!!

[bimmerboy12]

No ideas guys? I dont want to take it in and get raped. Is there a voltage I can check at the injectors?

[bimmerboy12]

A side note, it seems like the wavering idle is rhythmic sometimes, i was idling in drive, and it was lurching in rhythm.
It does not do it when the engine is ice cold, but it only has to warm up for a minute before it will start acting up.

[bimmerboy12]

Bump... I need some ideas for when I work on it this weekend!

[bimmerboy12]

Let's start with the simple, common causes:

did you disconnect the battery to perform all the servicing?

how long have you driven the car for since the servicing?

did you unplug the AFM for any reason? If so, did you plug it back in?

No, i didn't disconnect the battery for servicing since I wasn't dealing with any live leads.

I have driven the car back and forth to work 14 miles round trip every day since performing the service about three weeks ago. It runs perfectly fine and normal with the slightest increase in gas.

AFM is plugged in and I have unplugged/plugged nearly every connection under the hood looking for a loose connection... no luck.

[bimmerboy12]

It will diagnose if 1 of your connectors are bad. No, both leads on the coil are NOT positive.

I've had a problem like this before in a vert. There is 1 connector that goes from the coil down where the kick panel is, and it got lose causing the car to have a stumbling problem.

Well tried the battery to positive lead on coil method and no results. It still stumbled. I also re-bled the coolant system. No air. I soaked the entire manifold area with starting fluid, and no change in idle. This is really starting to piss me off. I went to a parade of homes tonight, and I was parking and the cop directing parking said, "sounds like your running outta gas there buddy". I gave an embarressed look of disgust and sheepishly drove to my spot, vowing to have the problem fixed by the weeks end.

[92 mtechnic cabrio]

Let's start with the simple, common causes:

did you disconnect the battery to perform all the servicing?

how long have you driven the car for since the servicing?

did you unplug the AFM for any reason? If so, did you plug it back in?