so i posted before about the pcv oil trap and i replaced that and passed smog. now ive run into an even bigger problem

once my car warms up, the cars idle is very choppy, the rpms jump between 500-900, and it stalls when i let off the brake at a stop sign. also, the car is spitting out thick black smoke and the turbo is not working...the gauge for the turbo works but i cant hear it spinning.

the thing is i cant see how changing out the oil trap could have caused any of this, it was running perfect before. any help would be very much appreciated.

 

Changing the oil trap would not cause this. A bad O2 sensor or MAF would. Are you getting any codes?

I am thinking you should change out the O2 either way.

 

ok so it seems that the turbo is actually working, at least i can hear it spinning. i just went out and bought new vacuum hose so im replacing them now.

does anybody have a picture of a 940turbo engine that could show me the correct placement of the vacuum hoses on the intake manifold please? im thinking i may have switched a couple of them when i was putting everything back on.

 

There should be a decal with a vacuum diagram stuck to your hood,look towards the bottom of the hood.Check your hoses from turbo to intercooler and intercooler to throttle body.These will deteriorate over time and split,run your hand underneath and feel for a split.Also check the connector on your coolant temp sensor,this is located near where you were working.

Dan

 

thanks to all the replies!

ok im going to have my codes checked tomorrow but i thought id let you know what happened today.
-it seems my turbo is working intermittently, stopping when the car gets warmed up.
-I replaced almost every vacuum line in my engine today, that didnt help at all
-while driving down the freeway with black smoke billowing out of my muffler, my tac needle started jumping erradically from 1000-5000rpm. i pulled to the side of the freeway and turned my car off. restarted and rpms stayed extremely low again (500-900)
-car stalled at stop light after shaking very noticeably, right before this happened the black smoke out of the muffler got worse

does anyone have any idea what could be happening? just to get peace of mind before tomorrow?

also any pics of 940turbo engines would help me alot!!!

 

nobody?

 

Black smoke indicates a rich mixture, the tach needle jumping indicates an ignition problem, I'm thinking the IECU is bad. I think you're not hearing the turbo because you're having a severe misfire and your engine is running rough. Take your intake hose off the front of the turbo and start the car, run it and see if your turbo actually stops at any point. If it is, your turbo is most definitely bad as well.

 

My 1987 740 turbo had trouble going up small hills and blew out black smoke while trying to do so. After months of trying to figure out the problem, I simply replaced the air filter. Problem fixed. Try this first.

 

Have you had the codes read?

Dan

 

had the codes read and had it diagnosed at a shop. apparently the codes were throwing because of the o2 sensor, but he said i need to replace my distributor too.
just curious...what exactly are the symptoms of a bad dist?
also, i cant find a haynes manual for a 1993 940turbo, does anybody have a link to a tutorial for changing an o2 sensor?

thank you to everyone who responded!!!

 

anyone? pleaseeee

 

you might want to check RPM censor behind motor and top of the bell housing.
it could bad one too.

 

Looks like the only advice you haven't gotten so far is to get a new car... not helpful!
Since the problem developed after you changed your PCV oil trap may be you should very carefully check your work: you probably diconnected, or broke, or connected something the wrong way.

 

since i first posted here is a list of things i have done to my car:
-new distributor cap and rotor
-new spark plugs and wireset
-new vacuum lines
-new full synthetic oil change and filter
-cleaned throttle body
-cleaned idle air controller
-cleaned mass air flow sensor (havent replaced yet im trying to not spend another $200 if i dont have to)
-new o2 sensor

this things going bye bye pretty soon in exchange for an easy to fix honda if this doesnt get resolved quick like!

 

bumpity bump

 

After you replaced your 02 sensor,did you clear codes?If you cleared the codes,is the cel on or off?


Dan