Cml2232

Ok first I have an 89 rs. The 305 was swapped for a 350 by the previous owner. I've ran into multiple wiring issues bc the swap they did was sloppy and now it has several seperate issues. To the immediate problem I was driving home and the car died. The situation with the starting is beyond my knowledge and I need help. The car is a 5 speed manual, when I start it I have to jiggle the key to keep it running. It tries to die but if you wiggle the ignition it will run no problem. You do have to crank it for a period of time bc it will only start when the oil pressure kicks up about half way on the oil pressure gauge. Which I do not understand. It's acting like my engine isn't priming itself and my oil pressure forces my fuel pump to kick on? Well now after it died yesterday the oil pressure is only kicking up a quarter of the way and it will not start. It's cranking strong but no start. I know checkin the obvious stuff first. Spark and fuel but the fact that the oil pressure is staying low makes me believe there's a relay or something that's stopping it. The oil is full and clean, any help would be appreciated.

armos

Sounds like you have a bad fuel pump relay. I don't know where that is but that's probably the reason for your starting problem.
The oil pressure switch provides a redundant path for getting voltage to the fuel pump. It will close the circuit once oil pressure gets primed. But normally, if the fuel pump relay is working, then it will activate the fuel pump immediately without needing oil pressure.
The pump should run for a couple seconds as soon as you turn on the key. It should also run as soon as you start to crank the starter. If it only runs after getting oil pressure then the fuel pump relay is probably dead, or something in the associated wiring.

This doesn't explain why you have to jiggle the key sometimes though. That sounds like a problem in the ignition switch.

Check your oil pressure with a mechanical gauge. The electric senders are unreliable and inaccurate, even when new. Very likely your sender is just going bad. That could also contribute to problems keeping the engine running since it's apparently the only thing left keeping your fuel pump turned on.

vetteoz

iTrader: (13)

https://www.thirdgen.org/forums/tech...formation.html


Correct

Your pump relay is not working to prime the engine when the key is 1st turned on and you have to wait for the engine OP to come up to operate the fuel pump OP switch which is a backup to the relay should it fail ;
which yours appears to have.

Cml2232

That's what I thought! Can anyone tell me what the relay looks like or where it's located? How hard is it to replace?

vetteoz

iTrader: (13)

Cml2232

Right but the relay has been bad for a while now, like I said the only thing startin the car was the build up of oil pressure that kicked my fuel pump on. But now the OP isn't kicking up anymore.. So is that the oil pressure sending unit or Is that a seperate relay?

Chad85T/A

iTrader: (1)

I'd replace the sending unit and the FP relay. Your sending unit may be going bad also.