runnig rough
Thread Starter
Registered User
Joined: Oct 2011
Posts: 1
Likes: 0
runnig rough I did a 94 LT1 corvette motor swap and need help with a rough running motor. The motor came complete with comp. that was "tuned" and the motor ran fine in old car. The motor sat about 3 years before install. I installed new inline pump and filter, headers w/o2 those are old, and EGR delete and a new summit MAS, summit fuel cell. Cleaned out the fuel rail of old gas and it fired right up. It runs rough at idle and stumbles on accl., sometimes it back fires. I changed plugs a wires, one plug had a lot of carbon, but no change. What can I check before the optispark.
TECH Apprentice
Joined: May 2009
Posts: 323
Likes: 2
From: NW AR
Most likely it is the ICM next to the coil failing. They can fail and not set off a code. Replace the Ignition Control Module with a decent unit, cost about 100 bucks. Another easy thing to check is the MAF, pull the Mass Air Flow Sensor and use some plastic safe electraclean on the inside. If it is really dirty then it can mess up stuff as well. Also post any of the SES codes that you get.
TECH Fanatic
Joined: Oct 2006
Posts: 1,106
Likes: 0
From: POULSBO WA.
A backfire is a classic sign of a lean condition. Was the pcm tuned for the vette or your car? Which is? I can't see your sig, a little info please. If it is in an fbody could be considerably heavier requiring mor fuel at take off. Either way still a lean condition.
