I have a 94 S10 with 4.3l vortec tbi. Drove fine one day and went to start it the next and it would not fire up just crank. Found out the pump was not working. Found the pump relay and swapped with new one and it chattered a little and started working. Next morning same thing, no start. Wiggle relay and it would chatter and then take off working. Then it quit working. I have tore the whole dash apart thinking a loose wire or something. I got it to run again but it would run rough and then smooth out and go back to running rough. Now after messing with it for a week the relay comes on as soon as you turn the key and stays on it won't go off. I have the pump unplugged to keep from burning it up until I find the problem. Any ideas??? Please HELP. Thanks.

 

When you messed with it for a week did you do something to the wiring for the relay ??

 

No. Thats what does'nt make sense. I am getting a signal straight from the computer for the relat to run and I am getting a signal back from the relay to the comp. telling it it is running, but the pump will not shut off. New symptom. I can start it up and slam the throttle down and it stalls out and pops flames back out of the carb.??? Sometimes the relay will just sit there and chatter like crazy. During this time the voltage from the comp. is up and down. HELP PLEASE!!!