ok so i recently put lsv in my 95 gsr tegg. had a ls and a b20 before that never had problems no cel nothing. then i put a lsv in and i had a p28 chipped on neptune and it ran fine for 2 weeks no wierd starting or no cel then one day i come out and turn the key on and noticed my fuel pump didnt prime and check engine light didnt go off about 5 mins with the key on it kicked on cel went off i had it jumped already so it wasnt throwing any codes. it was fine all day till i went to work. i get out of work and same thing no prime and solid cel. so i popped the hood and was checking the main ecu ground and it was fine thought maybe it was a loose connection so then i went to the ecu and unbolted it and layed it on my floorboard and fuel pump kicked on and cel went off. i bearly made it home that night cause every 5 mins it would just die and id wait about 5 mins and start up and drive again till it would die again. so i got it home the next day went out and started doing some tests but nothing car was dead had my friend come over with his demon ecu and plugged it in and car fired right up. had it in the car for 2 days didnt have a problem with it so i sent my chipped p28 back to the tunner and had him test it he got it and it was fine he tested it in different cars too just to be sure and didnt have a problem with it. so then i threw a stock p28 in car ran fine i parked it over night not even 15 hours i went out in the morning to go to work and nothing same as my chipped p28. solid ecu so im guessing something in the harness is crossed and causing the ecus to burn up i had my friend come over again with demon and his laptop this time to check sensor v and eld v and codes but nothing was out of the ordinary no codes and correct v so maybe some one has had the same problems as me in the past and can help me out that would be great!! i currently have a chipped p61 i threw it in the first day i got it and car started solid cel jumped but car was running and no throttle response till i unplugged the map then it idled fine and had throttle response. i threw the stock p28 in car fired up and threw code for map plugged it back in reset the ecu and no codes running fine so i let it sit over night go out and nothing once again and plugged the p61 in and nothing with that either.

 

sounds like your main relay is bad.

 

ive had a jumper for the main relay too it runs for 5 mins the shuts off with it same crap as with it plugged it. i get one click with the key on but no fuel prime. my fuel pump is good cause i jump it and it stays on and it sounds fine no wierd humming or screeching sound like it would be bad.

 

also on the p28 when it does run the cel goes away and the car runs with no codes.