$500 in parts- now have stumbling issue

[bmwpower]

Redo the test...can't hurt. Make sure engine is hot.
Throw a tablespoon of oil in those cylinders with low compression if you get low numbers again. If worn rings, you should see the number go up with oil in the chamber.

[bimmerboy12]

Redo the test...can't hurt. Make sure engine is hot.
Throw a tablespoon of oil in those cylinders with low compression if you get low numbers again. If worn rings, you should see the number go up with oil in the chamber.

OK, I am embarrassed to admit this, but I did the test wrong the first time... I just got this new compression gauge, and there is a screw-on connector at the end of the hose. So after I unscrewed the hose from cylinder 1, I unknowingly left the connector in cylinder 1 and screwed the hose right into each following cylinder, giving erroneous readings. SO... here are the NEW and IMPROVED readings:

1 - 145
2 - 145
3 - 150
4 - 165
5 - 150
6 - 150

Cylinder 4 may have some carbon build-up.

REGARDLESS, I think I am getting off-track from the root cause. Remember, this problem started when these new parts were put in.

ALSO- I re-tested the resistance of the CPS with my dad's ohm meter, and his measured it at 540 ohms, which is right on. My brand new ohm meter is faulty.

ANY OTHER IDEAS??? KEEP THE IDEAS COMING I WILL TRY ANYTHING!!!!

[ClassicScot]

crank sensor? spacing might cause a stumble could be exposed wiriing happend to me but this also cause temporary paralysis of my car! Maybe just adjust the throttle, could just be silly and needs to be adjusted slightly. You mentioned valve cover gasket, did you make sure the seal was tight no burrs or gouges? Some of these may sound stupid but it might just be a fucked up stupd thing.

GL
Andy

[bimmerboy12]

The Seafoam treatment might help... it certainly won't hurt.

Is Seafoam essentially equivalent to Ventil Sauber?

Clasicscot, my next plan of action is to pull the valve cover, re-measure my valve adjustment, and ensure everything is OK with the valve cover gasket. I will also re-bleed the coolant system just to make sure.

[bimmerboy12]

UPDATE: I pulled the valve cover last night and verified the valve tappet clearance and everything still looked good. I also put RTV on both sides of the valve cover gasket as it looked like there was still a little oil seeping through even though it was brand new.
I then did a valve soak with seafoam- let it drink the whole 16 oz. can at idle through a T in the fuel regulator vacuum line, had to pinch the hose to regulate or it will die. Added half can to the crankcase and the other half in fuel.....

WOW!!! MY CAR IS SOOOO MUCH FASTER!! It absolutely screams. It was like driving a different car.

However, the idle problem is unchanged. bummer.
Next is a coolant system bleed this weekend.

[ClassicScot]

any news on this i really want to know how this turned out.. hope you got it figured out.

[bimmerboy12]

any news on this i really want to know how this turned out.. hope you got it figured out.

Sorry, I didn't have time to work on it, worked on the power top on my wife's car all weekend. I will do a coolant bleed tonight or tomorrow and swap a fuel pump I have laying around just in case. I'll update ASAP.
Thanks again for all the suggestions.

[thereisnoyun]

replacing worn parts like these, alot of times can trigger sensor issue. Either from water getting on plugs when changing thermostat or water pump, or simply flushing the items can cause the sensors that were overdue to start acting up.

I would look at all the connectors on the sensor first. Even if you ahve done it, I would do it again. I say connection is your culprit if you check all the item with ohm meter.

I would make a list and do the scientific method and cross it out as you go. I know you probably ahve been doing this, but I dont know how diligently you have done them.

- cap, rotor, wire, coilpack, injectors, spark plugs, coolant sensors, connectors, ECU connection etc.

[bimmerboy12]

UPDATE:
I re-bled the coolant system thoroughly and there was no air. I sprayed electrical contact cleaner on male and female connections on all injectors.

No improvement. Same shitty idle.

Next I will swap a fuel pump in since I have a spare and see what happens.

[bimmerboy12]

UPDATE AGAIN: I swapped in a fuel pump I knew worked and nothing changed.

One thing I noticed is that the idle is definitely worse some times more than others. Seems like it is better with the warmer weather.

PLEASE give me some more things to try.
-b

[Spinning Tires]

I'm gonna go with vacuum leak. Theres a hose coming out of the bottom of the intake to the charcoal canister that is often over looked also the hose on the valve cover gets cracked. Usually a significant vacuum leak will trigger a CEL at idle

[bimmerboy12]

I'm gonna go with vacuum leak. Theres a hose coming out of the bottom of the intake to the charcoal canister that is often over looked also the hose on the valve cover gets cracked. Usually a significant vacuum leak will trigger a CEL at idle

If you read the previous posts, I have nearly exhausted every opportunity for a vacuum leak to exist. I replaced the throttle body to valve cover hose just because. I will double check or replace the hose from intake to canister. Remember I am getting 14.5 in Hg which is OK according to Bentley. Thank you for the heads up I will check it out and let you know.

[ClassicScot]

i dont know if this would cause a problem.... exhaust manifold gaskets. Maybe intake manifold gaskets. You are just looking for something that could be wrong. Every little thing. Im guessing that the things i said are vacuum leaks. this was probably already suggested, try a known working ecu. My friends e30 just stopped working, it was turing but not starting, got good spark, and power from the coil. The ecu was pooched.

good luck keep us posted

Andy

[Republic]

Not sure what the "short cut method" is for replacing the oil pan gasket, but revisit to make sure correct. No leaks, right?

How does the ground cable look from your Oil Pan to the driver-side chassis? New or shotty? replace if needed.

Have you replaced your Intake Manifold Gaskets? PITA, but worth a look. If going to do so, replace your Oil Down pipe O-rings and washers as well.

In addition, anything replaced with non-oem or peer-validated aftermarket parts, I would consider replacing again.

I would say good luck, but after 7 months of trial and error, that would sound sarcastic.

Godspeed.

[OrganicMechanic]

Decided to do some preventitive maintenance on my perfectly running 88 325i cabby, so did the following:

Oil pan gasket (shortcut method used)
valve cover gasket
camshaft seal and o-ring
timing belt
reference sensor
coolant temp sensor
wires
cap
rotor
belts
hoses
water pump
plugs
coolant flush

I got everything at Bavarian. I double checked all my electrical connections and cleaned with contact cleaner.

SO, when it started, it ran pretty good cold, but once it started warming up, started stumbling at idle. I can rev it up and it sounds good.

Don't suspect ICV since it ran fine before.
Check engine light was on right after finishing installing the parts, but disconnected battery and reconnected and it was not on after that.

What the flying f***.

Any help would be appreciated- you guys have bailed me out in the past so don't let me down now!
(thats you stereoinstaller)

check your timing belt marks.