$500 in parts- now have stumbling issue

[bimmerboy12]

UPDATE:

I put in a new intake bellows and replaced the bosch platinums with bosch super +'s gapped to .030... didn't do a thing, still idles like shit.

I am gonna lose my mind.

[bimmerboy12]

Just an update: I ordered Bosch Supers and will install this weekend. Can you believe I could not get Bosch Supers at Autozone, Advance, O'Reilly's, NAPA, Schraders, or Pep Boys??? Ordered from Bavauto. I will post an update at that time.

Anyone know what the proper gap should be?

Thanks

[mikekristine325ic]

bmwpower, what plugs did you end up using that solved the problem???
One thing that I will add: Sometimes I start it up when it is cold (and 25 degrees out) and the idle will waver about 200 rpm in rhythmic fashion, about one cycle per second. Then when warmed up, it will just stumble in random around -100 rpm, so little that it hardly registers on the tach.
I am doubting a vacuum leak at this point as I have scoured the engine with a tubed stethoscope, ether, etc. and have turned up nothing. When I pull the dipstick it immediately starts idling WAY WORSE. It seems electrical to me.

Same problem with my cabbie when I ran platnum. I am running Bosch Copper plugs and it runs beautiful!!!

As for pulling the dipstick, the engine is like a sealed unit. Taking off the oil cap or pulling the dipstick causes a vacuum leak thus idling crappy.

[discnick]

I put my old cap on, one of the tabs were broken completely off but somehow it still manages to run fine, all cylinders sparking... Im going to replace it at some point but its not at the top of my list of things right now, and when I do i'll be ordering oem so hopefully I dont run into the same problem.

[bmwpower]

Did you guys mess with the gap on your new plugs?

The platinums (which I don't use) come pre-gapped. You neeed to gap the coppers.

[E30nate]

check the crank referance wheel. it could have slipped a little bit so the timing is off.

[SpecM]

swap those plugs out for some Bosch or NGK coppers

[houstonh]

Did you guys mess with the gap on your new plugs?

[houstonh]

damn same thing here. I can see on my shitty A/F meter that the motronic is trying to adjust the A/F's and it seems I get the stumble at lean.. (this is a shitty AF meter though so take that with a grain of salt).

anyhow I have a the Bremi Cap/Rotor and I am wondering if I have the same damn issue.

please keep us posted.

Mine idles fine.. has no issues starting, runs pretty good. I get an occasion "bump" in the idle that drives me nuts. Definately seems like a miss to me.
I have changed the following. AFM, CAP, Rotor, timing belt, plugs, wires, coil, ECU, O2, intake boot, bled the coolant time and time again, valve cover gasket.

Question.. did you adjust the valves when you did your work? I have heard to tight of valves causing some "stumble". I know my valves were adjusted by the PO right before I bought the car (although they seem noisy as shit).

A few months back I did a MAF swap with new ecu, chip, TPS signal controller and I still get the F'n idle issue.

at this point I would be stoked if it was a cap/rotor issue, but I never thought to question it since I went with brand name shit.

[bimmerboy12]

I ended up sticking my old cap back on, im going to order an OEM one at some point, but that was def my problem..

discnick,
when you get a new cap (that actually works), could you let me know what brand it is and where you got it?
Thanks,
Brian

[andrewc53]

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)

I read through this post the other day because I have the same problem. I bought this car 90 325i about a month ago. I picked it up for 300.00 and didn't have ant history on it. I did the whole tuneup thing and timing belt. Had some air leaks and needed a FPR. took care of that. Same thing you are experiencing. Anyhow I was checking the connector to the O2 sensor and it was full of water. I blew the water out and put a little dielectric grease on it and it is running good now. Not sure you checked that or not but it did it for me. A Curtis

[bimmerboy12]

I ended up sticking my old cap back on, im going to order an OEM one at some point, but that was def my problem..

So the problem is solved with the old cap? Where are you getting the new cap?

[Erik j]

I just fixed my stumble, turns out my brand new OEM from the dealer cap was cast wrong. I suggest you replace your cap with your old one and go from there. I replaced all the same parts as you and ended up with the same problem.

[discnick]

I ended up sticking my old cap back on, im going to order an OEM one at some point, but that was def my problem..

[bimmerboy12]

Try disconnecting/reconnecting the battery.

Yeah, I tried doing that, letting it sit over 30 minutes and everything and it had no effect on the idle... Thanks though.