chandler810

hello everyone, ive been reading this forum for a long time and its been a lot of help, but i have a problem i cant find on hear. I switched a 93 TBI 350 to carbrated 4barrel and did everything like everyone else on here did, mallory 4309 fpr,HEI dis, and hooked what i could back up for sensors. the fule pump will prime up and give pressure with key on, but when i start the car the pump shuts off and i loose fuel pressure... i know the pumps are sometimes run with oil pressure sensor so i left that hooked up. i really just dont know whats going on so any help would be greatly appriciated, if someone has had this issue.

one92rs

iTrader: (5)

ok so it primes which means the ecm is still in there. that is how i did mine at first. then i put in a hobbs switch where the oil pressure switch was and used the same wiring. that way if i lost oil pressure it would shut off. what all sensors did you hook back up. did you remove any relays. besides the prime wire--green--the pump should run on its own. what wires did you cut. and was this problem present before. there are grey and orange wires that run the pump.

camaronewbie

Yes - the ECM will prime the pump, but since the ECM cannot detect a constant ignition signal (ie you no longer have a computer distributor), the ECM wikll not contiuously run the pump. Located the fuel pump relay, and wire it with a 12v+ in run wire to where the green/white stripe wire came from the ECM, then the pump will run contiuously as long as the key is on.

chandler810

thanks for the fast response, i hooked up a hot when run to the green/white wire and it works again. so i assume it still works threw the fuse hooked up this way right? a few finishing touches and i should be able to take it for a ride tomorow. then i hafto find the old thred about the TCC lockout, i think i seen it on here before.

one92rs

iTrader: (5)

there is a really good thread about the tcc lock up. we all used a vacuum switch and it worked great.

your oil pressure switch should run the pump unless you cut a wire somewhere.

also remember if you wire it hot you cant turn the key on and leave it. that is why i went to a hobbs switch. it came on at 5 psi. so i could turn the key on and it would not come on till i had 5 psi oil pressure.

ValleyBoy_D

Hey how did u get an ls1 rear end to run with your 3rd gen, all I can find as far as posi disk in my area are all ls rears but I was told u couldn't interchange it the 3rd gens? But anyway let me know what's up cuz I'm bangin my head on doors lookin for a decent disk posi

camaronewbie

Ls rear swap is a straight swap with exception of emergency brake cables.

Off topic here ... a search on ls1 rear swap will yield many hours of reading.