1996 850 GLT Very Rough Idle

EuroLo89 · Post by **EuroLo89** » 10 Mar 2014, 10:41

I also just changed out all the ground cables and the power wire from the alt to the battery all with 1gauge wire.

EuroLo89 · Post by **EuroLo89** » 10 Mar 2014, 10:46

I really don't think it's compression either. Yesterday while driving it, it was completely fine and driving normal; but as soon as it hit that point to where everything was warmed up then it felt like something was holding back it's full potential. First gear pulled alright as well as second, but everything after that felt sluggish like.

florbinginge · Post by **florbinginge** » 10 Mar 2014, 14:07

There are some tricky vacuum lines behind your intake manifold which commonly crack and break. Those would be worth checking if you haven't already. It may be worth checking if your PCV is clogged as well. You can test this by starting your car and removing the oil cap. Put a rubber glove over it and if it blows up the glove, your system is clogged. This happened to me without throwing any pcv codes

EuroLo89 · Post by **EuroLo89** » 10 Mar 2014, 23:23

Will the PCV system being clogged cause it to run like shit?

Post by **MoVolvos** » 11 Mar 2014, 00:43

_

Carefully double check timing.

Blessings,

BKM
_

Post by **rspi** » 11 Mar 2014, 03:51

I don't think a clogged PCV system will cause poor performance. Maybe a bad ECT, it can cause a bad fuel mix. Usually poor running after it warms up is ignition parts.

EuroLo89 · Post by **EuroLo89** » 13 Mar 2014, 11:20

Alright guys here's an update, check the codes again the other day and got the following: idle air control valve stuck open, idle air control valve stuck closed. Put a new iacv on it yesterday, but now it idles too high, so I tried adjusting the idle screw back and now it's not even touching and the car is idling at roughly 1300rpm. Guess I'm gonna replace all my vacuum lines with silicone hoses. Does anyone know where I can get a good vacuum hose diagram at?

Post by **bmncw** » 14 Mar 2014, 10:44

hi
have you checked the rotor?

Post by **rmmagow** » 14 Mar 2014, 12:50

Does an 850 have the same learn process for the IACV? I think I remember reading that the computer has to relearn things when screwing with the IACV. Something akin to disconnecting the battery for a longish period, reconnecting,, starting the car and let it idle all the way to full warm. I don't know for sure about a Euro car or which Motronic versions this applies to but I'm pretty sure the IACV has to relearn at some point.

EuroLo89 · Post by **EuroLo89** » 14 Mar 2014, 13:11

I already did that as well, two or three times at that.
Do all 850 models have a fuel return vacuum line coming off the intake, because mine doesn't and was wondering if that was normal?

1996 850 GLT Very Rough Idle

Re: 1996 850 GLT Very Rough Idle