96 850 Turbo Rough idle and die Topic is solved

volkans80 · Post by **volkans80** » 09 Sep 2016, 04:29

Hi,

My 850 (Motronic 4.3) started to random rough idle and sometimes dies. Spark plugs (bosch), plug wires (bougicord), distributor & rotor (bosch), o2 sensor (bosch), PCV system, turbo's small air hoses and vacuum hoses are new. First times there is 232 231 435 and replaced o2 sensor error codes gone but problem not changed. I doubt crankshaft sensor because one year ago car stopped running and i cleaned crankshaft sensor. Also there is strange behaviour. Sometimes when i push gas pedal it starts accelerating and stops, rpm downs a bit and then starts accelerating then repeat same thing.

Is crankshaft sensor can immediately cuts firing and lets it continue?
Is crankshaft sensor can effect idling?

Thanks,

Sommerfeldt · Post by **Sommerfeldt** » 09 Sep 2016, 05:17

The most probable possibility that's missing from your list is the MAF. Unplug it, start the car and see if the car idles / runs better without it. If it does, you've found your problem.

- S

volkans80 · Post by **volkans80** » 09 Sep 2016, 06:10

But mostly the car is running good. For example today i drive the car about one hour everything is ok but when i parking it die 6-7 times. 20 minute later i drive the car again 30 minute everything is ok. Two hour later i drive the car 30 minute everyting is ok. There is not a rough idle today but it died 6-7 times while parking.

Do you recommend unplug MAF and drive the car 1-2 days?

Sommerfeldt · Post by **Sommerfeldt** » 09 Sep 2016, 06:30

No, don't do that. When you're idling rough, stop the car. Unplug MAF. Start car. See if problem goes away/gets better. If it does, get a new MAF.

- S

volkans80 · Post by **volkans80** » 09 Sep 2016, 06:35

Ok I will try this. Thank you.

Post by **rspi** » 09 Sep 2016, 06:45

Is there a check engine light? What are the P codes?

volkans80 · Post by **volkans80** » 09 Sep 2016, 07:23

I don't know P codes but first times there are 232 231 435 dtc codes. When i changed o2 sensor all gone.

I don't know if it is related but yesterday i checked wastegate rod by hand and I just read codes again and now there is only 414

Post by **misha** » 09 Sep 2016, 07:30

Since you have intermittent problem and it points towards the Maf...i would try a zip tie method on Maf's connector.That's a common fault on these cars.

Did you reset codes and ecu after o2 sensor replacement?

volkans80 · Post by **volkans80** » 09 Sep 2016, 08:03

Yes maybe MAF's connector loose. I will try zip tie.

I cleaned codes but not ecu. How can i reset ecu? If i disconnect battery, ecu resets?

Post by **misha** » 09 Sep 2016, 08:33

After you zip tie Maf's connector,remove battery cables for around 15 min in order to reset ecu's fuel trim.

Maf connector is always safely secured with it's clip connector.The problem are the wires which connects to connector's pins.