Engine idels to fast after replacing head gasket.
Asked by wadee Oct 22, 2007 at 06:45 PM about the 1992 Ford F-150 S LB
Question type: Maintenance & Repair
After replacing the head gasket in my 1992 F150 3.9L 6 cylinder, the first time I started it the engine raced like it was at full throttle and the temperature gage does not show temperature. I can't time it or determine what happened to the temperature gage. Any help would be appreciated.
3 Answers
did you get all the vacume hoses back on and in correct order,as for temp did you plug wire back in for temp guage.
littlehorn answered 16 years ago
Yes, sounds like a vacuum problem, and the temp gauge may just be a disconnected wire.
meanoldmoe answered 16 years ago
The computer depends on the temp sensor to control fuel and idle . There are 2 sensors on the vehicle for sure , one for the dash gauge and one for the computer.....make sure they are plugged in and connections are not corroded/ rusty/ green !! Vacume leaks , and or improper vac hose connections will cause the engine to race . Low coolant level will affect idle speeds too , make sure you get in as much coolant as possable and bleed out all air locks in system. Make sure you don't have the throttle stuck open , or the cables binding as they will hold open the throttle plate and cause the engine to race too !!
