1988 3.9 surging then dies
#1
1988 3.9 surging then dies
truck starts idles for about 30 seconds then starts surging then dies, If I feather the gas it will run but not for long. I have replaced the map sensor, EGR,fuel pressure reg,coolant temp sensor and the TPS also put a new fuel pump in about 3 months ago. It could be going bad I don't know. I jumped the relay with a wire and the pump runs and I pinched the return line off no change. No codes are showing. I cleaned the grounds that i could find,Im at the end of my rope with this thing. I have a 318 out of a 74 truck that runs good Im thinking of putting that in but I hate to just give up on this little motor when it runs it runs like a champ. Any ideas
#2
#3
when i replaced the egr i turned the engine over a couple times and blew a bunch of debris out, but one thing i noticed is the vacuum line really doesnt have any vacuum. According to the vacuum diagram it's coming from the right place but i would think it would have noticable vacuum. I disconected the ICS and the truck would idle but still couldnt drive it as the surging just moved up the rpms untill it died. I did spray carb cleaner it it while giving it half throttle and it ran fine. could it be the fuel pump or injectors? Thanks for the help. Befor I replaced each part I checked everthing with an OHM meter and everything checked out but after getting frustrated I started replacing parts as to the code shown.
Last edited by rj67bu; 07-31-2011 at 05:28 PM.
#4