Y_B_A_FOOL

I have a 1990 Camaro with an '87 TPI l98 swapped in. I recently replaced the oil pressure sender (the one by the distributor, I believe that is the right name). After doing so I still don't have a pressure reading. I know that they made the oil pressure sender and oil presser switch into one sensor for my year car.

--> Would this cause my oil pressure gauge to not receive a signal? Or is this a hint that my gauge is bad?

I'm on a super tight college budget and I'm currently fixing the head gasket and gaskets along the way. I'm trying not to waste money playing the guessing game! Thanks!

Y_B_A_FOOL

Bump...

bulletxxx

i have a major problem regaurding a oil pressure sensor too.not trying to hyjack the thread but some input would help.i just removed theoil pressure sensor,mines the 1 just above the oil filter,it came out mad easy.the problem is when i went to put the new 1 in it wouldnt thread.i tried putting the old 1 back in ,in a desprite move to get the hole plugged back up and that 1 wouldnt go back in either.wtf.im worried about useing a thread chaser because its my block and am worried about metal shaveings.any ideas?

vetteoz

iTrader: (13)

Why? with what year sender?

How many wires on the connector ?

Ground what you think is the OP gauge wire to the block ; if the gauge moves then problem most likely with the sender.
If gauge doesn't move , a problem with gauge or wiring to it ( assuming you are testing the correct wire )

bulletxxx

ok guys im now in trouble.i was going to relocate my oil pressure sensor to the engine bay and when i did i had to cut the plug of to lengthen the wire.i cut the plug lengthend the wire and now my fuel pump wont go on.any ideas

Bobby Suth

iTrader: (2)

I beleave there is a safty in the system,so if you loose oil presure the fuel pump shuts down so you dont destroy your engine.Maybe your not getting a good signal or could be because you dont have oil presure you ecm has shut off the fuel pump.

bulletxxx

so how do i get it to turn back on lol.the connections are all good.the car turns over,and starts briefly when some carb cleaner is sprayed in the throttle bodies.the injectors arent spraying fuel and i dont hear the fuel pump energizing.

vetteoz

iTrader: (13)

There is nothing to tell the ECM what the oil pressure is

Wrong
OP switch is only there as a backup to keep pump running should the pump relay fail
When everything is working as it should ;
even if the OP switch disconnected from low oil pressure ,the pump would still be getting power through the relay and engine would continue to run
Check pump circuit below

bulletxxx

ok i pulled the fuel pump relay and it is clearly burnt out.without that relay the pump wont energize correct?

bulletxxx

there are 3 male prongs on the bottom of the relay and the middle prong which is connected to the red power wire is completly burnt up.the plug that plugs into the relay is fried as well.i hope just replacing the two will fix the problem

bulletxxx

is it possible to use the a/c relay just to check it or are they not compatible

Zig

There are 3 ways to get power to the fuel pump. You can apply 12 volts to the ALDL connector (G in the diagram Vetteoz provided) and the fuel pump should run. This is a test circuit and verifies the wires from the relay to the pump and the pump itself are good. When you turn the ignition on, the ECM provides a 12 volt signal through the Green/White wire which closes the fuel pump relay for 2 second to prime the pump. You can then start the car. When oil pressure comes up, the oil pressure switch closes and the pump is provided 12 volts through the OP switch and the engine continues to run. If the OP switch does not close, the engine will die as soon as the fuel pressure from the prime drops off.

In summary, there are 3 ways to get power to the pump, Relay to prime the system, OP switch for normal operate and ALDL to test the pump. The red line going back to the ECM in the diagram above is how it determines if you have low voltage for the fuel pump circuit (Code 54).

If you have a 4 wire pressure switch, it is an integrated switch and sender. I think the 87 L98 had seperate switch and sender though.

With a burnt relay, your engine will not start until the oil pressure builds up enough to close the OP switch. I recently saw another person with this problem in an 89 L98. He had a miswired relay that would not turn on. After cranking for about 10 seconds, the pressure would build, close the OP switch, start the fuel pump and the engine would fire and run. He could also jump the relay (E to A in the diagram above) and get it to fire immediately.

If you have any questions, let me know!

bulletxxx

you guys are the best.thank you for all your help.ill be dambed if it wasnt the fuel pump fuse.took me 4ever to find the thing.some1 once upon a time moved it to inside the fender opening on the passenger side.i got lucky a noticed some wires leading into the hole and wouldnt you know it it was in there.replaced the fuse and BAMB fuel pump works.

bulletxxx

what is the normal oil temp for a 1992 camaro 305 tbi.my after market gauge starts at 120 and has yet to go over that.do i have a bad sender or does it take a bit to get over 120