Ok, have a qestion about the fuel pump operation on my 92 RS 3.1. I did a search and found nothing I was looking for. Ok I know if you turn the key to run and don't start the engine the pump will run for a second to prime the system and then turn off if the engine is not started. Well I have noticed that some times the fuel pump is louder than other times, somtimes you don't hear it at all over the exhaust and others you do, also on my TA with a new delco pump in it after the turn the car off I hear the pump run for a second-everytime, but the Camaro only does this now and then, sometimes I hear it run after the car is turned off and others it shuts right off. Do I have an upcomeing issue on my hands? The car runs fine, once this past Saturday it did not want to start right away, but once it did it ran great.

 

The reason the pump runs a bit after being shut off is because of the oil pressure switch. Until the engine oil pressure drops below about 10-15 PSI, the oil pressure switch remains closed and the pump continues to run after the engine is shut off. The OPS is a sort of bypass switch for the fuel pump in case the relay fails while driving (code 54).
if the pump seems abnormally loud, it could mean it could be getting ready to die (bearings) or it could be nothing and that it just seems loud.

 

I know about the sound, I had 2 Mustangs, the pumps never went out, but my god the pumps are loud on them, the new Delco pump in my TA you can hear it all the time, the one in the Camaro that from what the OP tells me is not all that old, but is not a Delco pump-some aftermarket one. It's just odd to me that sometimes you don't hear it and other times you do, also I understand about the oil PSI switch, but why does it not do it every time? Like I said on my TA the pump runs after the engine is shut off every time and the Camaro it's now and then?

 

Maybe the oil pump switch in the Camaro is getting old and sometimes isn't working. I know that on my 87 the fuel pump ran for an extra 2-3 seconds with the pressure switch after every shutdown.

The pumps in the Cavalier and Grand Prix were pretty quiet. The one in the 87 was loud. I'm hoping the external pump I'll be putting in the 88 isn't going to be too bad...

 

The switch could be bad has my oil PSI gauge is always pegged high when running, but I also think the gauge might be bad as it never rests all the way down when the car is off like the other gauges. Well I will keep an eye on it and hope for the best. Thanks for the help as always.

 

You could try replacing the oil pressure unit... If the gauge is pegged, it generally means that the oil pressure sender is open (not going to work). Figure out which terminal is connected to the white wire of the connector, and then probe it with the DMM. With the engine off, there should be 0 ohms resistance between the terminal and a good ground. Anything more than that means it's junk.

 

Good info, the sender is right there by the oil filter right? If so I can see it with the hood open, gotta love all the room in there with a V6 LOL! so let me get this right just so I know. If the sender is shot the gauge will just be pegged all the way high when the engine is runing right? Like I said the gauge never rest all the way down, never has since I bought the car, all the other gauges seem to work fine, well the fuel gauge likes to float around some, but the one on my TA does that as well.

 

most aftermarket pumps whine a good bit

i have three delco corvette zr-1 fuel pumps in the tank of my twin turbo iroc , with 2 on its obnoxious , with all 3 pumps running it sounds like a jet engine winding up

if its a typical walboro 255 its going to be noisy , the edelbrock pumps are also rebranded walboros so those are loud as well

 

If the OPS is faulty, the gauge will peg if the engine ISN'T running but with the key on because the gauge circuit is open (and the gauge only gets power with the key on).

Fuel gauge bounces because of lack of baffles in the fuel tank... Got to love sharp corners with the gauge showing less than half a tank. Chug, chug, chug, vroooom! (that would be fuel flowing away from the sending unit until forces and fuel level stabilize and the pump actually starts pumping again)

Oh, boy, a really noisy fuel pump. Oh, well, guess that's what I get for not wanting to drop the tank every time the thing goes and takes a dump...

 

Ok well my oil gauge pegs high when the car is running no matter what the RPM is. I thought my 92 has the baffles in the tank-I thought I read all 91/92 3rd gens got that upgarde as before it was for the 1LE cars.

Yeah the Delco pump in my TA is louder than the pump in the Camaro, and sometimes you don't even hear the Camaro pump, other times you do??? Well as long as the car runs I'm not going to worry about it and keep working on the body.

 

I just had this problem in my 3.1 your pump is on the way out. To delay it make sure to change your fuel filter.
It makes more noise when your low on gas as well because your pump literally sits In gas. When your low on gas your overheating the pump which could cause premature failure.


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[quote=mcrandrz;5528934]I just had this problem in my 3.1 your pump is on the way out. To delay it make sure to change your fuel filter.
It makes more noise when your low on gas as well because your pump literally sits In gas. When your low on gas your overheating the pump which could cause premature failure.


I always have about 3/4 tank or more. The pump went bad in my TA last year and it ran like crap if it ran at all, my Camaro runs good and the fuel pressure was tested not long ago. I just found it odd that the pump does not always run for a sec or so sometimes when the car is tured off.