air leak

[LordAthey]

ok guys im stumped. So after replacing a head gasket in 1969 put everything back together. When i tried to start it the fuel pump wouldn't quit priming itself. So i left the key on and I heard a hissing sound on the fuel rail keep in mind the fuel pump is still going. Its hard to tell if its coming from the injectors or the fuel rail, but the car will not start. I don't know what else to check, but I'm still stump on where this air is leak any help would be great-full.

Thanks,

Scott

 

[Lancer99]

Did you check the little gaskets on the injectors? I had that happen to me with my moms car. I know it's not a mitsu but its a start.

 

[LordAthey]

I checked the o-rings and replaced those i'm still stumped on what it could be /ubbthreads/images/graemlins/dunno.gif

 

^^Did you check the insulators as well? make sure all your intake mani bolts are tight. Do you smell fuel when doing this?

 

If its not leaking any fuel out then i kind of doubt its air leaking out of the fuel system. Do you see any fuel leaking?

I would bank on a vacuum leak around the fuel rail area. A quick test for vacuum leaks is to spray some brake cleaner around the leaking sound and see if the idle raises.... if so you have a vacuum leak.

 

[LordAthey]

Alright well i cant smell fuel you just hear air and the fuel pump keeps going. So when i get home tonight i will check to see if there is a vacuum leak and let you guys know happened.

Thanks again,

Scott

 

The FPR is actuated off vacuum so it could make sense for the fuel pump to act strange if you have a large enough vacuum leak.... /ubbthreads/images/graemlins/dunno.gif

 

[LordAthey]

Ok guys heres the deal. 1. I figured out that the fuel is flowing through the fuel rail and down the fuel return line. 2.thats why the fuel pump doesn't shut off is cause the fuel just keeps flowing through the fuel rail. 3. starts with carb cleaner and stays running. Timing is dead on so i'm still stumped.

 

[Barnes]

Do you have an extra FPR you could try? Almost sounds like the FPR is broke and is wide open. Perhaps you aren't building enough pressure in the fuel rail. Do you have a fuel pressure gauge? Might be worth buying a cheap bolt on pressure gauge just to make sure that isn't the problem.

 

+1 on the FPR.

Be sure it is hooked up well to the vacuum source, and I know the autozone by me rents fuel pressure gauges you can use to check the system......

 

[LordAthey]

Well I used a FPR off my other galant and its doing the same thing. I made sure all the vacuum lines are hooked up correct. BTW its completely stock, so what do you guys think that it could be?

 

so, it starts with carb cleaner, and will keep running.... sounds like the fuel pump and injectors are capable of delivering enough fuel then. Wonder if its a sensor and the car isn't even trying to deliver fuel when you are trying to start it up, but once it starts it is delivering fuel. /ubbthreads/images/graemlins/dunno.gif Not too sure if thats even possible.

Do you have any type of logger or ECU modifications? Has your dead timing been messed with at all?

 

[LordAthey]

I swear it won't start, but once there is carb cleaner in there it fires right up and stays running i let it run for 30 mins. Now you see why I'm confused, cause i have no idea what it is. The car is completely stock, no ecu mods, no mods at all for that matter. No, I don't have a datalogger I wish I did. I had to replace a head gasket so I don't think i messed with the dead timer. I have replaced a head gasket once before on my friends galant and when we did that it started right up. So I'm wondering like you said 92Galant926 if there is some sort of sensor that has gone bad?? /ubbthreads/images/graemlins/dunno.gif /ubbthreads/images/graemlins/dunno.gif /ubbthreads/images/graemlins/dunno.gif

 

[Barnes]

After you get it running does it drive?

 

[LordAthey]

Yup I drove it a mile down the road and back just shifting at 3k.

 

very strange.... Dead timing is the time at which your injectors fire in each rotation, so just doing a head gasket couldn't mess with that, its a setting in the ECU.

Even while you are driving no fuel leaks out, or it doesnt smell like fuel when you get done driving? It is still leaking air right? I would try to stop that leak first cause until you know where that is coming from its hard to pin point the problem.

If the leak either gets fixed, and its still doing it then my best guess would be that something in the ECU is messed up, or that some wire got snapped under the hood while you were working on it.

 

[LordAthey]

Well its not leaking air at all. The fuel is still running. From what i think is that the fuel is running through the fuel rail then down the fuel return line. No wires got cut or anything i went back and check all the hook up's. I unplugged the wires to the injectors, turned the key and you could still hear fuel running through the fuel rail. This point i think it is some fuse or something, because it seems like the system isn't getting pressuried. Once again today my friend is bring over a fuel pressure gauge so we can look at it. This has been one hell of a problem. /ubbthreads/images/graemlins/banghead.gif

 

Sounds like it. I would try to test the fuel pressure in the line going to the rail and in the one leaving. That will help determine if your FPR is doing its job.

One other thing to try would to be to take the CAS off, but leave it plugged in and turn it over by hand. (you need the key in the on position) You should be able to feel the injectors click as you turn it over. If they are not clicking then something is wrong.

 

[LordAthey]

Alright when i get home tonight i will take the CAS off and see if the injectors are clicking. Let you guys know what happened tomorrow.

 

[LordAthey]

Update well took the cas off injectors are clicking. I took it for another drive last night and when I floored it the car didn't go any faster just kept moving foward at the same speed (like if you barly pushed the gas down it was accerlating the same as when the pedal was to the floor). Now I have a couple other guesses 1. fuel filter 2. fuel pump. and 3. ECU. now we did get the pressure test and it was only at 15 psi.