Spitzfiya

So when i first got my GTA running the shop forgot to check the oil level and I ran the car for a day or so on low oil.

It would bog down and stall every 5 minutes it seemed and then would start right back up again.

After i topped off the oil and let it sit over night it was fine and didnt stall out but bogged down when you punched it.

After I ran some Seafoam through it it seemed to get rid of all the problems.

Now im wondering do thirdgens have some sort of Low-Oil engine cutoff?

Sorry for the noob questions lately...we have to start somewhere

Ward

iTrader: (1)

There is an oil pressure switch, but not oil level. The fuel pump is powered by the oil pressure switch, which closes around 5 or 6 psi. As long as you've got oil pressure, that's not the problem.

Red Devil

No there is no cut-off and no your fuel pump is not dependant on the oil pressure switch for power.

Sonix

iTrader: (1)

Really? I thought TPI cars had their fuel pump relay wired through an oil pressure switch, to shut off fuel if the oil pressure died. I must have read that on this forum, ergo it must be true!

jv9999

iTrader: (1)

The OP switch is a backup for the FP relay. If the relay fails and it still has pressure, the pump keeps running. It will run until it seizes. They don't put OP cutoffs on cars because of liability. If it cuts off at the wrong time it can cause an accident.

ryan91rs

iTrader: (1)

I can guarantee if the pressure drops low the engine will cut out. I had put my dad's oil in my Maro by accident and it was thin synthetic. Went to a red light oil hit the red zone on the gauge and the engine cut out on me.

level no but pressure yes.

calamitascamaro

iTrader: (5)

Funny, I put sythenic in my car by accident once too, nothing happened to mine except some of the gaskets that normally don't leak started to. Replaced the gaskets, went back to dinosaur oil and had no problems. Just saying.

ljnowell

um, no. There isnt. What would happen if you oil pump crapped on the interstate? The car would shut off and lose power steering and power brakes at highway speed on a crowded interstate? LAWSUIT! GM did not set these cars up to cut the engine in the case of low oil pressure. IF the pressure drops low enough the engine will die due to lack of lubrication, not an electronic programming to cut the engine.

ryan91rs

iTrader: (1)

say what you will. Maybe yours is broken but my pressure was low, in the red zone and the check engine light came on and the engine shut off. Changed the oil and no problems. What do you want a video? I was in the car staring at the gauge freaking out just about to reach for the keys to kill it and she turned off. Turned it right back on and gave it some throttle to keep the pressure up. Changed back to regular oil pressure was fine and no problems since.

And if it was low on lube (been there done that in a different chevy) and if it shut off because of that there would be significant damage like spun bearing or knock. Plus the pressure was just below the red (about 5lbs). I had all 5 quarts but two were synthetic thus too thin and pressure low.

jv9999

iTrader: (1)

There are two possibilities here. One is that your fuel pump relay wasn't working and the oil pressure switch was powering the pump. The other is that it got hot enough internally that the motor bound-up and then freed when it cooled.

As designed with everything working, it will run until it can't run anymore.

calamitascamaro

iTrader: (5)

OR the other possibility is that all of our GM's are broken and yours is the only one with a low oil pressure shut off switch that works, or that the guy that owned it before you put one on there from a Honda Lawn Mower.

gordo420

iTrader: (1)

89RsPower!

As stated above there is no low oil pressure cut off on our cars. That must be one heck of a worn out engine to have that low of pressure just becasue you put synthetic in it..

calamitascamaro

iTrader: (5)

five7kid

iTrader: (14)

Synthetic isn't thinner than petroleum. Another urban myth that won't die.

If you put in a lighter weight synthetic, that is a different issue. Or, if there was some sort of unusual incompatibility between the petroleum and synthetic you put in there.

But, that's off-topic (just couldn't let misstatements go unchallenged).

Spitzfiya, assuming you do have a relay malfunction, and your fuel pump did cut off because of low oil pressure, you may have damaged your engine (to answer the question in your other low-oil thread).

Ward

iTrader: (1)

Look at the wiring diagram, the fuel pump power runs directly through the oil pressure switch. The fuel pump relay does not stay on, it's what primes the pump. Then, you crank the engine over, oil pressure rises, and the pump kicks back on.

ljnowell

Thank you for posting that diagram, saved me the time of getting it from alldata.

As you can see the power for the fuel pump travels in terminal e of the relay and out terminal a. This is what runs the fuel pump, per the ECMs instruction.If you follow that it will run to t he white and tan wire that goes to the fuel pump. If you look at the OPS, to the right of it you see a dot. That dot represents a splice. Had you used a better quality diagram that would have been noted as a numbered splice, with a an s in front of it. If you could kindly show me, where the tan/white wire leaving the fuel pump relay goes through the ops on its way to the pump, I will gladly mail you my ASE card.

In reference the post above, if your car died its because of a bad fuel pump relay probably. When you lost oil pressure the power was cut, as the relay was non functioning. As I said before, an auto manufacturer will not make a vehicle that would willingly shut down on the interstate and kill someone. Even the newer systems dont work this way. A lot of newer vehicles will kill spark and fuel to 1/2 of the cylinders and pump air to cool them down in case of a radical overheating. It will alternate the cylinders and keep it from melting down.

Ward

iTrader: (1)

That was the way I originally thought it worked, but if the ECM controls the fuel pump with the FP relay, then what is the point of the oil pressure switch? If the FP relay is closed, then I don't how the oil pressure switch being open or closed would change any part of the circuit. Although, it would make sense to have it as a backup for the FP relay.

ljnowell

When the relay is closed, the OPS doesnt affect the circuit at all. Its simply a parallel leg. When the relay fails though, the ops will keep the car running, instead of dying where it is. Relays really like to fail too. At least one of every 5 no fuel situations I see is a bad relay. Especially in the toyotas, hondas, and that flavor of rice.

Damon

That's right- the OPSU is a PARALLEL way of getting 12V to the fuel pump, it is not DEPENDENT on the fuel pump relay, nor is the relay dependent on the OPSU. They are independent/parallel ways of getting power to the fuel pump. If EITHER ONE is active (circuit is closed) the FP will run.

You'll also notice that power to the OPSU is NOT through the ignition switch. It's hot all the time (through the 20A ECM fuse). I was reminded of this fact recently when priming the oil pump on a new motor. As soon as oil pressure came up the fuel pump kicked in, even though the key was not even in the ignition! Ever notice that your fuel pump will stay running for a few seconds after shut-down? I believe that's why. It often takes a few moments for oil pressure to drop to zero (below 4 PSI, which is the cut-off point for the OPSU switch) after you turn the engine off.

Agreed with above, if your oil pressure drops low and your fuel pump shuts off, it's probably because your FP relay is bad or the ECM isn't triggering it like it should for some reason. You're running only on the OPSU curcuit.