Rough Idle at cold start

[leadtrombone]

For those that might remember i had a bad head leak (turned out to be a crack) a while back. I had just bought the car and after some back and forth the dealer agreed to fix it.

By fixing they simply had the engine replaced.

Not sure of the history on the "new" motor, but it runs well. and a bit queter than the old one. It fixed my vacuum issue (the fuel consumtion gauge would not go to 0 at full vacuum) and it now idles at 700-800rpm instead of 1000-1300.

all that is great but when i start up in the morning (especially) and after a long sit (like at work for most of the day) it idles really rough. Stall a couple times untill i get going.

I'm thinking a cold idle solenoid, or somehting like that. Anythoughts..

and how hard to replace..??[bmwdance]

 

[E30m42cab]

How's the fuel flow? Replaced the filter lately? Fuel regulator okay? Just an idea.

 

[leadtrombone]

How's the fuel flow? Replaced the filter lately? Fuel regulator okay? Just an idea.

good thought. I will check. However the other engine did not have this problem at all. And i am quite shure that those parts were not swapped out..

Wait.. Are those mounted to the block here... i have to check.

I know on later cars they are farther back in the fuel system...

 

[Doughnut]

The small vacuum hose that goes to your fuel pressure regulator (if faulty) will be hard as a rock, pull the small vacuum hose off at the inlet end of the FPR and check to see if there is fuel present inside (indicating failed diaphram within the FPR) If you can't see any fuel but there is a heavy smell of "gasoline" when you pulled the hose off, is a good reason to replace too.

This is my experience with them anyway - I had the same problem and this fixed it.