Gas leaking out through exhaust

[rmurray]

2004 GXi 5.0L with SX drive. Gas is leaking from outdrive while running. It's coming out with the fresh water. I've pulled the fuel pressure regulator and it was contaminated, but not totally blocked (at least I don't think so). I ordered the e-clip to replace the screen as instructed by VP. I've tried checking for issues at the injectors by attempting a drop test by disconnecting the connectors one at a time to see if one is clogged, but after going through several of them, it is very difficult to notice any change in idle. Even pulling the plug wires one at a time makes no discernible difference. AM I not doing it right? Does the engine need to warm up first? I figured the idle would drop a noticeable amount. Maybe I'm not waiting long enough? Can someone tell me how to do this properly? Thanks!

 

[alldodge]

Depending on which GXi it probably uses batch firing. Batch firing turns on more then one injector at a time. While each cylinder has its own injector, it doesn't get turned ON only when the cylinder needs fuel.

With fuel coming out with the water, I would check fuel pressure first, and it could also be that the injectors are stuck turned ON and do not turn OFF. If you get a noid light you can test injectors to see if they are turning ON/OFF

 

[rmurray]

Depending on which GXi it probably uses batch firing. Batch firing turns on more then one injector at a time. While each cylinder has its own injector, it doesn't get turned ON only when the cylinder needs fuel.

With fuel coming out with the water, I would check fuel pressure first, and it could also be that the injectors are stuck turned ON and do not turn OFF. If you get a noid light you can test injectors to see if they are turning ON/OFF

The noid light will just check the signal though, correct? Will it tell me if the injector is stuck open? And if so, how do I check that? Thanks!

 

[chs marine service]

if the pressure regulator has ruptured, it will suck fuel into the intake through the vaccum line., pll the line off and shake it, see if fuel comes out.

 

[rmurray]

if the pressure regulator has ruptured, it will suck fuel into the intake through the vaccum line., pll the line off and shake it, see if fuel comes out.

I pulled it and nothing came out. Should I replace the regulator any way, or is replacing the screen with the e-clip good enough? Bosch regulators are $30 on Amazon.

 

[alldodge]

The noid light will just check the signal though, correct? Will it tell me if the injector is stuck open? And if so, how do I check that? Thanks!

Correct, just listing possibilities
The vacuum line shake the chs mentioned would be a good thing to check also

 

[rmurray]

Correct, just listing possibilities
The vacuum line shake the chs mentioned would be a good thing to check also

Maybe I'll run it again and see if any gas comes out. I should pull it after running for a few minutes? So if an injector is stuck open, will the noid light help me identify that? Will the injector signal be different in that case? Thanks.

 

[alldodge]

I pulled it and nothing came out. Should I replace the regulator any way, or is replacing the screen with the e-clip good enough? Bosch regulators are $30 on Amazon.

Start the motor and if the diaphragm is ruptured fuel will start coming out with the motor running

 

[rmurray]

Start the motor and if the diaphragm is ruptured fuel will start coming out with the motor running

No fuel coming out, only air. Regulator doesn't appear to be ruptured.

 

[alldodge]

Maybe I'll run it again and see if any gas comes out. I should pull it after running for a few minutes? So if an injector is stuck open, will the noid light help me identify that? Will the injector signal be different in that case? Thanks.

If there is no flashes then the ECM is the issue. If you see flashes then the injector(s) may be stuck.

Can pull the injectors and have them flow tested. Cost is 15 to 20 for each, and needs to be tested (if done) to 6000 rpms. Use a marine test facility and not an auto one

Which GXi do you have? This will help advise better as how your motor is configured

 

[rmurray]

if there is no flashes then the ecm is the issue. If you see flashes then the injector(s) may be stuck.

Can pull the injectors and have them flow tested. Cost is 15 to 20 for each, and needs to be tested (if done) to 6000 rpms. Use a marine test facility and not an auto one

which gxi do you have? This will help advise better as how your motor is configured

2004 5.0l gxi-e. I think I can hear all the injectors ticking. I should probably use a screw driver to the ear to check the clicks?

 

[alldodge]

Don't know, if you can your ears are better then mine

 

[Scott Danforth]

Presure test the raw water side of the fuel cooler

Fuel pressure higher than water pressure.

 

[QBhoy]

Hi
i have the mercury equivalent of this engine. Mine will throw fuel out the exhausts until it warms up. They over fuel when cold usually. It also gets worse when the diz cap is on its way to being done.

 

[rmurray]

Presure test the raw water side of the fuel cooler

Fuel pressure higher than water pressure.

Scott, can you elaborate? What would cause that? Thanks.

 

[rmurray]

Hi
i have the mercury equivalent of this engine. Mine will throw fuel out the exhausts until it warms up. They over fuel when cold usually. It also gets worse when the diz cap is on its way to being done.

This is leaking even at normal op temp. Not sure if the cap, wires, or plugs are bad, but the boat only has 70 hours. Not sure if they are possible candidates, but I'm considering changing them all out. I really don't think that is going to fix my issue. I'm guessing its a stuck injector, but I'm open to anything that might help.

 

[Scott Danforth]

you have a fuel injected engine. there is a fuel cooler, specifically the module that the fuel pumps sit in is water cooled. it is a few stamped pieces and a few machined pieces that are brazed / soldered together. there are two locations that if there is a seam leak, will leak high pressure fuel into the raw water stream.

pressure test the raw water side with air, 15-20 psi should hold forever.

 

[alldodge]

To find out if the pump is leaking into the cooling water, disconnect both water lines from the pump and plug or connect them together. Start the motor and see if fuel start coming out of the ports

 

[rmurray]

Thank you Scott and AllDodge. I will check. I'm thinking you guys are right since this fuel pump has been my downfall. Thanks again!

 

[Lou C]

Hi
i have the mercury equivalent of this engine. Mine will throw fuel out the exhausts until it warms up. They over fuel when cold usually. It also gets worse when the diz cap is on its way to being done.

That just does not seem right....even my ancient 4.3 with the 4bbl Quadrajet doesn't do that with the slow-to-open up auto choke!