Gas getting into oil
Thread Starter
Staging Lane
Joined: May 2017
Posts: 67
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Gas getting into oil Alright so I have a bit of a situation. I recently replaced the crankshaft on my 1994 firebird lt1. I noticed that when I start the car after it's sat long enough to cool down completely, the idle would start off lower than the normal 750rpm at park and 550rpm in drive. It was still driving fine just not getting optimal gas mileage. I then noticed the oil pan leaking. Today I took it off and found out there was gas inside the pan. Now, the car has aftermarket aluminum heads with roller rockers, and is cammed. It also has a walbro gsl392 fuel pump motor. But, I never had this problem beforehand, even with this set up. The car was already tuned and everything and it ran perfect with no gas issues before. It still idles fine after a few minutes and isn't misfiring or anything. Do need to get the pcm flashed? The car was sitting for about 7 months. Or do have an injector stuck open or something? Any advice will be highly appreciated.
Last edited by fischdogg1; Jun 1, 2017 at 01:00 AM.
Thread Starter
Staging Lane
Joined: May 2017
Posts: 67
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Also I did replace the fuel injector orings but I don't think that has anything to do with it. The gas was getting into the oil pan and leaking before. I did put rubber fuel hose onto the fuel lines to connect to the fuel rail lines. I don't think that would have anything to do with it either but I just want to make sure.
thats not how those seals work, they seal the top of the injector to the rail and the bottom seal goes into the intake. you could potentially leach a little but your talking about one side under pressure (top) but the other side vacuum (bottom) so it would pool on the intake and be sucked in.
More likely you have an injector stuck open causing over fueling. take a screw driver or pry bar and use it as a stethoscope. start it and at idle take the blade end and place it against the injector and put the handle against your ear. you should hear a click with each injector pulse, so go from injector to injector to listen for the click its audible so you should hear it and if not you could potentially have one stuck open.
there's probably a test write up for checking the fuel pressure that could determine this also but i dont know it.
More likely you have an injector stuck open causing over fueling. take a screw driver or pry bar and use it as a stethoscope. start it and at idle take the blade end and place it against the injector and put the handle against your ear. you should hear a click with each injector pulse, so go from injector to injector to listen for the click its audible so you should hear it and if not you could potentially have one stuck open.
there's probably a test write up for checking the fuel pressure that could determine this also but i dont know it.
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Injector could be the issue. However I had the same problem but mine was from driving it and parking the car before it would get up to operating temps. I rarely drive mine and normally would be just a quick trip to the store and back without letting it reach full operating temps. Or just turning it on to hear the cam for a bit or something like that. I had gas in my oil and once I changed the oil and let it warm up/full operating temp before I drove/turned it off and parked it I haven't had any issues sense. Mine also has aftermarket crank/heads/cam like yours. Hopefully yours is a similar, easy solution.
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Thread Starter
Staging Lane
Joined: May 2017
Posts: 67
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Alright so all my injectors are clicking. I also tested the injector connectors with the noid light. The only test I haven't done is putting a multimeter up to the injectors. But, when I start the car it still starts off at a low idle. When I press the brake for some reason the idle goes up and if I keep pressing it the idle eventually goes up to normal at park. Is it still possible their's a bad injector regardless? Or the fuel pressure regulator? It seems dry though. If the computer was sending too much fuel to the car wouldn't the car go into limp mode and shut off?
Alright so all my injectors are clicking. I also tested the injector connectors with the noid light. The only test I haven't done is putting a multimeter up to the injectors. But, when I start the car it still starts off at a low idle. When I press the brake for some reason the idle goes up and if I keep pressing it the idle eventually goes up to normal at park. Is it still possible their's a bad injector regardless? Or the fuel pressure regulator? It seems dry though. If the computer was sending too much fuel to the car wouldn't the car go into limp mode and shut off?
Thread Starter
Staging Lane
Joined: May 2017
Posts: 67
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So the injectors weren't leaking when I took them off the the intake. I did all the tests and they seem to be okay but I'm pretty sure I've got some kind of clog or something. I am getting an immediate gradual drop in pressure when I prime the pump (initial 48 PSI) . The pressure on the FP gauge also rises (Around 55 PSI) when I start the car while at the same time the idle is below normal RPM. I checked the regulator and it's working. Does anyone have anymore suggestions before I go ahead and get new injectors?
Last edited by fischdogg1; Jun 10, 2017 at 04:26 PM.
Thread Starter
Staging Lane
Joined: May 2017
Posts: 67
Likes: 0
I replaced the regulator and no still no go. I've got that rough idle yet, even to the point where my car wants to die sometimes. I haven't checked fuel pressure since the new regulator, but I will tomorrow. The fuel pump is pretty new and the motor is kicking in fine. At this point I'm not sure what else could cause this issue other than an injector. Running rich while at low RPM at idle; and, gas was getting into oil ! The FPR made sense but nope.