S50 running issues

[328ijunkie]

lame :(

[Danny]

Well I'm at work currently, I can't work on the car until I get home lol.

[328ijunkie]

Figure it out? Anxiously wondering if i win ;) lol

[328ijunkie]

You can fix the late model one to work. You dont need to replace it.

[Danny]

Haha I probably will. I just found the part numbers.

Early: 11-61-1-730-265

Later: 11-61-1-738-629

If anyone is curious. One is coming to me today.

[328ijunkie]

^Not at all. Call my shop number and ill walk you through what you can do if youre near the car.

oh and ill need you to mail me a beer when i fix it for you

:P

[Danny]

You have part numbers? I used one for a 95 M3 as I assumed they were the same.

[328ijunkie]

no iat is the same but the snap in connector is different:

vs

[Danny]

^Depending on what year it came from it is different. Where is your IAT? Under the manifold or by the BB nipple?

It is by the BB nipple, the previous one was under the intake. Is it a different IAT?

[328ijunkie]

^Depending on what year it came from it is different. Where is your IAT? Under the manifold or by the BB nipple?

[Danny]

Never had a FPR go bad... like ever...
Your flooding out the motor big time if you dont have a chip for the 21.5's.
17's to 21's is a big jump and the OBD1 electronics will never be able to compensate for that.

And by the vid. You have a Vac leak. The RPMs drop when you open the throttle not rise immediately.

I have just replaced every single vacuum component with brand new parts. I'm not sure how there could be a vacuum leak, unless an M50 nonvanos intake manifold is different from a vanos m50 intake manifold.

[328ijunkie]

Never had a FPR go bad... like ever...
Your flooding out the motor big time if you dont have a chip for the 21.5's.
17's to 21's is a big jump and the OBD1 electronics will never be able to compensate for that.

And by the vid. You have a Vac leak. The RPMs drop when you open the throttle not rise immediately.

[Danny]

fuel pressure regulator?!?!

Replaced that a while ago with a new one. Could be an issue though I suppose.

[e30rapidic]

fuel pressure regulator?!?!

[Danny]

Did you unlpug the MAF while the car was running? I think it could be normal for it to stall if unplugged while already running. My understanding is that the car should run in some sort of limp/fail mode if the car is started with a dead/unplugged maf. I could be wrong about all of this, but if your car can't ever run without maf, it might be a clue to narrow things down to something beyond my knowledge.

Correct, I only unplugged it once it was running. I'll give it a shot before I start the car as well.

Something else that came to mind is the throttle position sensor. I remember a friend who would have unpredictable throttle response due to this, especially when stabbing the pedal. However, that was on an M20 and I don't know if it's directly relevant to S50s as well.

I'll have to probe around with a multi meter, that could be a possibility.

As for a head gasket leak, I don't think it would cause those symptoms. You'd notice other things before performance issues that severe, like some real obvious oil and coolant mixing and a much cloudier exhaust than what you're seeing. I don't have any guesses for the clogged cat, but at least that's something you can disconnect and test without spending money if you do it yourself. Don't failed cats result in a sulfur/rotten egg like smell? Maybe that's not always the case.

I agree with the your thoughts on the head gasket. As for the cat, I'm not sure.