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.

 

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.

 

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.

 

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.

 

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.

 

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

 

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.