Need advice ASAP
#1
Intermediate
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Need advice ASAP
I have been having a fuel pressure loss issue and gas in the oil on a 96 LT1 and the answer on CF always seems to be leaking injector, replace your injectors. Took the car to a shop to have the injectors and regulator replaced and they sware up and down its not the injectors but the intake gasket.
They say there is no way a leaking injector would cause that.
Do they know what they are talking about?
They say there is no way a leaking injector would cause that.
Do they know what they are talking about?
#5
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An intake gasket causing a fuel pressure loss? Doesn't sound right to me. A bad fuel regulator or leaky injector would cause that symptom as well as account for gas in the oil. I'd get a second opinion.
Dave T.
Dave T.
#6
Safety Car
Unless I'm confused what in the world does the intake gasket have to do with fuel being in the oil? If I were you unbolt the injector rail, lift the injectors and the rail off the manifold and turn the key to pressurize the fuel system. If you have a leaking injector you will see it. Like 4 screws and 5 minutes of your time.
#7
Safety Car
There are automotive books/ classes for those who want to learn how an engine works. This is an example of why you can't believe everything online!
Last edited by 5abivt; 05-10-2011 at 01:56 PM.
#8
Race Director
Find a new mechanic. The intake is under negative pressure (vacuum). Fuel will not leak into the oil from the gasket. Change the injectors.
#9
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#10
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The lose in fuel pressure could be a diffrent problem all together just because they are happing at the sametime.
The Intake is a sealed system form the lowwer end even if the injector is leaking and the intake is sealed it should not get into the oil unless the gasket is leaking.
The old style when the fuel pump was driven off the cam lobe and the seal of the fuel pump went bad thats anouther way gas could get into the oil, But the fuel pump is in the tank the side of vlock has a block off plate where the fuel pump of the old days mounted.
#12
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If the injector has leak down after shut off the motor it could leak pass the gasket If it leaking not when it running.
The lose in fuel pressure could be a diffrent problem all together just because they are happing at the sametime.
The Intake is a sealed system form the lowwer end even if the injector is leaking and the intake is sealed it should not get into the oil unless the gasket is leaking.
The old style when the fuel pump was driven off the cam lobe and the seal of the fuel pump went bad thats anouther way gas could get into the oil, But the fuel pump is in the tank the side of vlock has a block off plate where the fuel pump of the old days mounted.
The lose in fuel pressure could be a diffrent problem all together just because they are happing at the sametime.
The Intake is a sealed system form the lowwer end even if the injector is leaking and the intake is sealed it should not get into the oil unless the gasket is leaking.
The old style when the fuel pump was driven off the cam lobe and the seal of the fuel pump went bad thats anouther way gas could get into the oil, But the fuel pump is in the tank the side of vlock has a block off plate where the fuel pump of the old days mounted.
The shop has called and said they have found that the EVAP solenoid is not operating properly and said this is my problem....what do you guys think?
#13
Tech Contributor
The pressure problem seems to occur after an HR of driving and while the engine is off, as if the injectors get hot then leak.
The shop has called and said they have found that the EVAP solenoid is not operating properly and said this is my problem....what do you guys think?
The shop has called and said they have found that the EVAP solenoid is not operating properly and said this is my problem....what do you guys think?
Gas in the oil is one of two things...injectors, or a failed fuel pressure regulator.
#14
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All they said is "EVAP is your problem" not evap is causing gas in the oil so im going to call back and double check.
EDIT:
The shop says faulty evap solenoid causes the fuel to not be recycled properly thus leaking it into the engine.
Any ideas? They want $178 to pop one of thoes in....fack
Last edited by themadvetter; 05-10-2011 at 04:18 PM. Reason: .
#15
Race Director
The injector shouldn't be leaking after shut down. There should be no fuel to leak past the intake gasket. If that is what is happening, the op needs to change the bad injector, not the intake gasket.
#16
Tech Contributor
I have never seen the SES light on... I have been fighting with them about what the problem is all day so they ran diagnostics for free.
All they said is "EVAP is your problem" not evap is causing gas in the oil so im going to call back and double check.
EDIT:
The shop says faulty evap solenoid causes the fuel to not be recycled properly thus leaking it into the engine.
Any ideas? They want $178 to pop one of thoes in....fack
All they said is "EVAP is your problem" not evap is causing gas in the oil so im going to call back and double check.
EDIT:
The shop says faulty evap solenoid causes the fuel to not be recycled properly thus leaking it into the engine.
Any ideas? They want $178 to pop one of thoes in....fack
If you are losing fuel system pressure, that will occur from one of five things...
- injectors
- fuel pressure regulator
- fuel pump check valve
- fuel pump
- fuel line leak (which will be really obvious given 40psi+ of pressure)
If you have gas in your oil, it will be from one of two things...
- injectors
- fuel pressure regulator
Lastly, gas does not leak past intake gaskets. The injector shoots fuel directly into the intake port on top of the intake valve. The gas puddles on top of the valve. If the valve is partially open, the gas drains past and onto the piston, past the rings, and into the pan.
#17
Drifting
My Washingtonian friend above is correct. Injectors, or fuel pressure reg. Pull the vac hose off of the regulator and check for gas (with engine and key off!). If it is making it to the oil through there, there should be plenty of gas. Wear eye protection!
#18
Le Mans Master
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Cruise-In X Veteran
St. Jude Donor '09
The EVAP does not recycle liquid fuel. It is for fuel vapor from the fuel tank. These guys are barking up the wrong tree.
If you are losing fuel system pressure, that will occur from one of five things...
- injectors
- fuel pressure regulator
- fuel pump check valve
- fuel pump
- fuel line leak (which will be really obvious given 40psi+ of pressure)
If you have gas in your oil, it will be from one of two things...
- injectors
- fuel pressure regulator
Lastly, gas does not leak past intake gaskets. The injector shoots fuel directly into the intake port on top of the intake valve. The gas puddles on top of the valve. If the valve is partially open, the gas drains past and onto the piston, past the rings, and into the pan.
If you are losing fuel system pressure, that will occur from one of five things...
- injectors
- fuel pressure regulator
- fuel pump check valve
- fuel pump
- fuel line leak (which will be really obvious given 40psi+ of pressure)
If you have gas in your oil, it will be from one of two things...
- injectors
- fuel pressure regulator
Lastly, gas does not leak past intake gaskets. The injector shoots fuel directly into the intake port on top of the intake valve. The gas puddles on top of the valve. If the valve is partially open, the gas drains past and onto the piston, past the rings, and into the pan.
#19
Instructor
Might wana get a quote for a blinker fluid refill at that shop, cause it sounds like they might do that too. I'd find myself a new mechanic (yourself if you have tools handy). It's one thing to be able to do good work and not know exactly how to explain it to someone, but this place is clearly throwing parts and guesses at your problem.
#20
Le Mans Master
Shoot, changing the injectors on an LT1 you need a 10mm socket and a set of injectors.
Might need needle nose pliers if the assembly clips are still in place.
To change the FPR, same 10 mm socket and IIRC its a 6mm to unbolt the FPR
Set of injectors from FIC, FPR from parts store, an hour at the MOST of your time and its done.
Might need needle nose pliers if the assembly clips are still in place.
To change the FPR, same 10 mm socket and IIRC its a 6mm to unbolt the FPR
Set of injectors from FIC, FPR from parts store, an hour at the MOST of your time and its done.