Alright R3V. Im 80% stumped. (Now 90%) New development

[Wishno87]

Started diagnostics on a 89 325i this morning.

Symptoms are:

White smoke from tailpipe (not billowing but still present)
Runs rough like its only running on a few cylinders
Very little power and revs take a while to raise when you hit the gas
You can pull the plug wires on cyl 2,4,6 and it doesn't effect the way the car runs
Smells like gas pretty bad

Things I have swapped from a known running car:

Plugs. (gaps checked)
Plug wires (still suspect though)
Brand new cap was installed by Mr Ryan (what a gentlemen ;))
Rotor
AFM
O2
ECU
Coil


Things I have done:

Comp test on "dead" cyl Round 170 for each
Sprayed electrical connection cleaner on the injector harness connector


Help me R3V! Tomorrow I plan to install new plug wires and change injectors and injector harness.

[antil33t]

Fuel Pressure Regulator?

[Wishno87]

Fuel Pressure Regulator?

Good idea. Shouldn't be to hard to change out.

[lolcantturn]

Rewire that C191. The injectors fire in two banks- Bank 1 and Bank 2. one bank is cylinder 1,3,5 while the other is cylinder 2,4,6. The C191 connector has wiring separating these two banks, I bet one of those wires went bad, so just rewire the whole thing.

[toointoxicated60]

Agreed ^

[CorvallisBMW]

I know this will sound dumb, but does it have enough gas in the tank? And how old is it? Also check the fuel filter.

[Ryann]

I know this will sound dumb, but does it have enough gas in the tank? And how old is it? Also check the fuel filter.

Oh it's got PLENTY of fuel. Shitloads of it- filling up the dead holes, fouling the plugs, and spewing out the tailpipe.

Rewire that C191. The injectors fire in two banks- Bank 1 and Bank 2. one bank is cylinder 1,3,5 while the other is cylinder 2,4,6. The C191 connector has wiring separating these two banks, I bet one of those wires went bad, so just rewire the whole thing.

This could be it. I vote swap injectors for the offending holes.

[LowR3V'in]

Another dumb suggestion, but recheck to see if you have the firing order
correct. I once mixed up #1 and #6 on the dizzy.

[Ryann]

^The car broke while going down the road. Unless there's an evil squirrel living under the hood..

[lolcantturn]

^The car broke while going down the road. Unless there's an evil squirrel living under the hood..

Yep sounds like C191.

If you look through my M20 threads, theres this long complicated one in which I basically did EVERYTHING except the C191. Before the motor completely stopped working, it was running on 3 cylinders and really hard to start. It happened while I was driving. I basically did everything, every sensor, every injector, 3 ECUs, swapped the head, nothing. It was my C191, and it had exactly the same problem as you, I could pull the plugs from cylinder 2 4 and 6 and the car would run the same.

Rewire that C191 or just get another harness.

[Wishno87]

Awesome! That stuff is a pain to get to but at least its a lead. Thanks!

[gtdragon980]

agreed on the c191, sounds exactly like my problem i had.

[Wishno87]

Good! About to get started right now. Luckily i have a 90 325i that I have been swapping parts between the whole time.

[Wishno87]

How do I take that harness out of the ring holder thing? Never had a late model before so im a little lost. I screwed off the C191 connector but I need to remove the injector side of the harness from the mount thing.

[Wishno87]

Did injector harness. Still nothing. Going to do CPS and im just about done. Not really much left. Still running on only 1,3,5.