Need help... intermittent engine cuts etc

[ajnmlax30]

Hi all

I am new here, and also new to BMW... as an owner anyways. I'm an Audi guy, yeah yeah I know.... :)

I just picked up a 1989 325ix a month or two ago and went through just about everything which I'll get into here in a minute. I'm looking for ideas on chasing down an issue that didn't start until after I replaced the head gasket, so had a ton of stuff apart obviously.
Car: 1989 325ix stock as far as I know 253xxx miles

The car had an extremely high idle when I got it 2000 Rpms. Several torn hoses etc all replaced and a torn intake boot. The head gasket needed to be done so I did a TON of stuff while in there.

My issue now is that I get an intermittent engine cut for lack of a better way to word that.... seems to mostly be in between shifts especially when letting off the throttle after being WOT. CEL will flash, car bucks a few times then straightens out and is fine. Occasionally I'll get a CeL when the car is sitting at idle which can be sporadic but usually around 800-1000rpms. If you tap the gas the CEL immediately goes off. Doesn't appear to come on during normal driving or when I'm hammering on the car only in between shifts or as otherwise mentioned if I release the throttle quickly after being 50-100% down. Stomp test reveals one code 1222 which can be 6,000 things most of which I've replaced. No vaccum leaks that I have been able to find.

Now this issue started after doing the work and replacing pretty much anything and everything I could think of, I'll try to list it all below. I have been trying to track this down for weeks so any help is much appreciated.

Replaced:

Head gasket and bolts
Timing belt and tensioner (timing is fine)
Water pump
All radiator hoses
ICV
Intake boot
All vaccum hoses (that I know of)
Blue and brown temp sensors
Fuel filter
Intake filter
Plugs (twice to make sure)
Rotor and cap
Fuel pressure regulator
Throttle position sensor
Valve cover gasket
Oil cap
Fuel cap
Charcoal canister
Purge valve
Exhaust gaskets
02 sensor
All cooling system stuff (radiator,thermo, etc)



Not replaced:
Ignition coil (ordered)
Fuel pump??
Ecu? Have had a bit of water or moisture in glove box will pull ecu to see if it's got any on that.



I am also wondering if it's the TPS... I lined it up as best I could w the old one but wasn't sure if there is a specific way to line that up and wondering if the throttle is not closing or opening properly under certain conditions? I've read it should make 2 clicks... one right when you activate throttle which I have and a second at about 70% or so throttle, I only have one click not two.

[M_3_X]

What about your CPS? Didn't see it on your list and most of the times is the culprit for engine cut out sporadic issues when they start to fail.

[Maddog]

Just went through an intermittent stall problem. In short, it had to do with the engine harness. Initially, I thought I had found the problem with corroded wiring at the C191 conector (wire corroded to a point of braking off the pins when touched), but continued to stall after repairing connectors. Replaced all electrical mechanical parts that would affect ignition with no cure; this included the CPS.

Finally decided to have my trustworthy and talented German car specialist take over. He discovered a broken shielded wire on the harness and replace the harness. I allowed him to keep the car as long as needed to make sure it would not stall again.

I suspect it's your harness at the connector especially if the harness was disturbed while you did the head job.

[ajnmlax30]

Just went through an intermittent stall problem. In short, it had to do with the engine harness. Initially, I thought I had found the problem with corroded wiring at the C191 conector (wire corroded to a point of braking off the pins when touched), but continued to stall after repairing connectors. Replaced all electrical mechanical parts that would affect ignition with no cure; this included the CPS.

Finally decided to have my trustworthy and talented German car specialist take over. He discovered a broken shielded wire on the harness and replace the harness. I allowed him to keep the car as long as needed to make sure it would not stall again.

I suspect it's your harness at the connector especially if the harness was disturbed while you did the head job.

Thank you guys for the responses...

So yes I considered the CPS and could potentially change that as well.

I do want to touch on the C191. So I stumbled a couple weeks ago on something about that connector being a huge PITA.... all the symptoms in that thread were what I was experiencing.... so I decided why not? I unplugged it and no visible corrosion etc... however I plugged it back in made sure it was secure, etc... and for about a week or so the car was running significantly better.

Also, not every time... but sometimes on a cold start I will start the car and it will immediately die... start it again and it fires right up and will run more or less fine.

Sorry just trying to think of anything that helps point me in the correct direction.

So I'm thinking it has something to do with that harness or the plug as well... just not sure where to even begin. Either that or the TPS are my two main guesses and I apologize for not remembering to put that above.

So what exactly would I want to look for besides anything noticeable (which I do not see) on the c191? Yes it was undone while the head was off of course... and as I said makes sense since the issue didn't start until we put it all back together.

I read stuff about hard starts, flashing CEL, engine cutting out etc all relating to that plug so it does make sense. I had the motor completely shut off on my two times in one day prior to unplugging it and plugging it back in, that has yet to happen again. I unplugged it and checked once more yesterday and cleaned the connections w electrical connector cleaner.

So am I looking at the entire engine harness or just something around where I touched? Thanks again for any and all help!

[Kershaw]

http://www.r3vlimited.com/board/showthread.php?t=372569

Go thread my thread here, maybe it'll help.

[ajnmlax30]

Thanks for the replies.

I wanted to update this as I am still having the issue.

Since my last post I have also replaced:

CPS
Adjusted the idle switch it was not in the correct position not closing fully
Cleaned and checked connections of the c191 appears fine
Replaced ignition coil


After each one of these things my issues overall went away for some time.

However I still get these cuts and I'm noticing that they seem to coincide with when it is raining.... 100% worse. There was a tear in my CPS wiring and this made a big difference, for a week or so but today this started again.

I think the only thing I have yet to replace is the maf or the afm whatever it is. I still get code 1222 if I do have an air leak I for sure cannot find it. Everything else seems to function properly. My idle is still not perfect and the cut outs w flashing CEL etc continue. As before, if I go WOT it mostly happens between shifts or after going WOT then releasing the throttle quickly. Any more suggestions would be awesome!

[YosemiteSam]

Definitely take a look at your AFM. Your problem sounds like the AFM signal dropping out. This is a fairly common problem. I had a similar problem with my car and I am currently waiting for a refurb from BavRest.

[ahlem]

You say you adjusted the idle switch. Do you meat TPS? If that's not adjusted properly you could have a similar problem.

[ajnmlax30]

Thank you again for the responses.

Yes the TPS is what I meant and as of now I'm 99% sure that's adjusted correctly and functioning as it should. It for sure was not before, wasn't allowing the throttle plate to close all the way.

Yes the AFM is the only thing basically I have not changed.

I really thought I nailed it after doing the CPS since it ran great for a while after. Still could be a break or issue in the C191 that I cannot see I guess too but everything visually etc looks fine.

When the engine cuts out and the CEL flashes etc the car will often jerk pretty hard and I'll get a strong waft of "rich" fuel type smell then all goes back to normal. Not sure if this info helps.

The search continues I guess!

[tim88325is]

"Cleaned and checked connections of the c191 appears fine"

Did you check under the rubber boots? Check for corrosion or insulation damage where the wire enters the connectors, not between the two halves. Water makes its way into the boots and sits.

Replacing my connector with aftermarket weatherproof connectors made a big difference for my car in terms of idle, which I thought was kinda illogical but I think the wires were ready to fail completely from corrosion.

[Hooffenstein HD]

"Cleaned and checked connections of the c191 appears fine"

Did you check under the rubber boots? Check for corrosion or insulation damage where the wire enters the connectors, not between the two halves. Water makes its way into the boots and sits.

When mine failed, wires were broken on both sides of the connector. Connector itself looked fine.