Engine runs rough until @ 200*?? Opinions
Thread Starter
Race Director
Joined: Dec 2003
Posts: 12,599
Likes: 1
From: Texas
Engine runs rough until @ 200*?? Opinions
A buddy of mine has a 92 C4 that almost seems to be missing when it is cold. It runs very rough (almost like a it has a good size cam in it) until it reaches around 198 degrees (most of the time this temp. will be the point it starts running smooth.) He has done plugs and wires and is thinking that it is the opti causing this, anyone here have any suggestions I could run at him?
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
Factory Service Manual by Helm,Inc. to determine actual procedure to systematically eliminate potential problem areas/parts? May actually be cheaper than replacing parts only to find that the problem is still there.
Instructor
Joined: May 2006
Posts: 202
Likes: 16
Originally Posted by vetterlatethannever
A buddy of mine has a 92 C4 that almost seems to be missing when it is cold. It runs very rough (almost like a it has a good size cam in it) until it reaches around 198 degrees (most of the time this temp. will be the point it starts running smooth.) He has done plugs and wires and is thinking that it is the opti causing this, anyone here have any suggestions I could run at him?
I would look at vacuum leaks. A hot engine can stand lean much better than a cold one. Add propane when cold idling & see if it smoothes out.
(Go to a vacuum line, like the PCV. Whatever you do, don't run it through the MAF!)
