Ok I recently had a mechanic replace my old 4.3 liter engine. I purchased a remanufactured engine from NAPA. The problems I'm gonna explain to you didn't happen with the old engine. Ok to telll you what has been replaced since the new engine has been installed is new oxygen sensor, water pump, all new temperature sensors, spark plugs/wires, thermostat, radiator, drive belt, fuel pump/sock, throttle position sensor, fuel filter. Ok now to my horrible problem, when I crank the truck up it has no problems at all. It is idling at about 900 to 1000 rpms when idling. It runs and drives excellent. When I drive it for a few miles only when it is idling (not driving) in gear, it will shut off completely and then crank right back up and drive good till I get to the next redlight or stop sign! My mechanic says the timing is good, and there aren't any vacuum leaks. When the truck cuts off in idle it throws a service engine soon light on in the dash. When the truck is running this light or other lights don't come on, it only comes on when the truck cuts off in idle. Also he checked the TBI and its gasket and they both are good. The fuel injectors are spraying good. A diagnostic test revealed no codes, and didnt reveal one when it cut off in idle after it threw the light! I have ran sea foam, other various fuel cleaners through it but still problem occurs. Everytime I drive the truck it cuts off when idling in gear, but it only does it after it has warmed up after a few miles. When it is idling in gear the engine will jerk and then suddenly cut off, but it will crank right back up with no problems! Please help this is aggravating because nothing im doing seems to be working. My mechanic has been working on cars for 40 years and he is even baffled and doesn't know where to turn. Also the truck will cut off when i put it into reverse sometimes, but it will crank right back up and go into reverse normal if this happens the next attempt. Only after the truck has been driven for a few miles does this problem occur with the reverse issue. It also smells rich coming from the tail pipes when running as well.
Sep 7, 2010 at 1:59 PM