Engine Car spewing fuel

silverlx50 · Jul 3, 2020

I'm trying to diagnose a fuel problem. My car basically went into limp mode and was spraying fuel out of the tailpipes.

Now when I crank it to start it, it literally leaks fuel out of the midpipe at every connection. Something seems to be flooding the engine with fuel.

I bought a new Walbro pump recently but no other changes have been made. I have also had extreme fuel pressure in the tank too.

Running and during priming the pressure would be about 42 psi.

Now, it goes to 42 psi when priming, as soon as the priming is done, the fuel pressure literally falls back to zero in about 1 to 2 seconds.

7991LXnSHO · Jul 5, 2020

What is the pressure key on, line off and plugged?

silverlx50 · Jul 5, 2020

Presssure KO is right around 42 only while priming. I havent taken and lines off. Just lriming it four times and testing pressure caused fuel to drip out of the mid pipe

General karthief · Jul 5, 2020

Check your oil, if it smells like gas don't start the engine. Change the oil ahhh after you resolve the problem.
I would pull the upper intake off then take and test each injector to see which one is stuck open.

Mstng93SSP · Jul 5, 2020

Sounds liks an injector stuck full open. You might be able to pull your plugs and figure out which cylinder is full of fuel and that is the injector stuck open. Like carthief said, do not start the engine like this.Change your oil after problem is resolved.

Chris

7991LXnSHO · Jul 5, 2020

Most people do not mean actually running that much fuel out the exhaust.
check the fuel pressure properly after finding the gusher. Also, no smoking near this car. I hope it did not ruin a cylinder and rings.

Dan02gt · Jul 5, 2020

If the fuel pressure regulator has failed it could be forcing fuel through the vacuum port and into the intake manifold.

General karthief · Jul 5, 2020

Dan02gt said:
If the fuel pressure regulator has failed it could be forcing fuel through the vacuum port and into the intake manifold.

I agree, pull the vacuum line off and smell it

silverlx50 · Jul 5, 2020

I pulled the vacuum line from the regulator but it isn't wet and doesn't smell badly of fuel.

Checked oil, It doesn't smell like gas. Most of the car does now but I smelled the dipstick tube but I don't get a strong gas smell, just slightly from the engine bay.

I pulled all the plug and found the drivers side plugs were dry.

Passenger side plugs, #4 soaked with fuel, #3 about half wet, #2 maybe a couple drops and #1 is dry. All 8 plugs look the same other then the fuel.

silverlx50 · Jul 5, 2020

General karthief said:
Check your oil, if it smells like gas don't start the engine. Change the oil ahhh after you resolve the problem.
I would pull the upper intake off then take and test each injector to see which one is stuck open.

Could 1 bad injector cause several plugs to be soaked in fuel? #4 plug was soaking wet then as I went forward the fuel decreased until I got to #1 which was dry.

I was hoping the regulator went out, it is 27 years old.

General karthief · Jul 6, 2020

Ahh, I would get the injectors checked out. Read this:

Injector Cleaning - InjectorRx

Restore your engine's performance with professional fuel injector cleaning services. Get fast, guaranteed results from InjectorRX.

www.injectorrx.com

silverlx50 · Jul 6, 2020

I'll begin testing these today. I'll use jrichker's method of compressed air, a glass and soapy water.

silverlx50 · Jul 6, 2020

I had zero luck testing the injectors. I'm sure I'm not doing something correctly.

When I pulled my upper intake off, I turned it over and a lot of gas came out in the ground, probably a 8" puddle of gas.

Dan02gt · Jul 6, 2020

silverlx50 said:
I had zero luck testing the injectors. I'm sure I'm not doing something correctly.

When I pulled my upper intake off, I turned it over and a lot of gas came out in the ground, probably a 8" puddle of gas.

Well there you go. The injectors are in the lower intake. The upper should never see any fuel. Only way for fuel to get in the upper is via the fuel pressure regulator.

7991LXnSHO · Jul 6, 2020

Problem found, I hope.
While things are apart, did you do the electrical tests on the injectors? I am thinking about resistance and making sure they click with even a 9v battery, but not near the leaked fuel. It would be a great time for new O rings.

Dan02gt said:
Well there you go. The injectors are in the lower intake. The upper should never see any fuel. Only way for fuel to get in the upper is via the fuel pressure regulator.

silverlx50 · Jul 6, 2020

7991LXnSHO said:
Problem found, I hope.
While things are apart, did you do the electrical tests on the injectors? I am thinking about resistance and making sure they click with even a 9v battery, but not near the leaked fuel. It would be a great time for new O rings.

Man I hope so too. I didnt do electrical tests, I dont have what I need to do electrial testing without the risk or short circuit in the pos and neg possibly ruining an injector or more. I need wire and Id like to have some alligator clips. I'm adding them to my toolbox list now lol.

I will be doing new o-rings while they are out and now I've gotta wait for new upper to lower gaskets to arrive so I'll put this thing on hold until probably Friday. Its a good time for me to dump my used oil and buy new oil to put in before I try and crank it up.

silverlx50 · Jul 8, 2020

The car is not back together yet, waiting on lower to upper intake gaskets and injector o-rings from LMR, but I put my new FPR on last night and the car does hold fuel pressure now.

I'm wondering if the FPR was going bad and was causing my extreme tank pressure after doing the Walbro 255 pump as the return line looks great.

silverlx50 · Jul 8, 2020

Changed the oil today. I'd estimate 2 quarts of fuel was mixed in with 7 quarts of oil.

Dan02gt · Jul 8, 2020

That’s a lot of fuel delusion. Hopefully your mains are OK.
If you’re getting a lot of pressure in your tank it could be the vent line is blocked or the purge solenoid is not working.
The 255 is a big pump, really to big for the stock lines, and can cause some serious turbulence on the return. If could have also added to the demise of your FPR. If you’re making the kind of power that requires a 255, upgrading your fuel lines and fuel hanger the the ProM one would be useful.

silverlx50 · Jul 8, 2020

Dan02gt said:
That’s a lot of fuel delusion. Hopefully your mains are OK.
If you’re getting a lot of pressure in your tank it could be the vent line is blocked or the purge solenoid is not working.
The 255 is a big pump, really to big for the stock lines, and can cause some serious turbulence on the return. If could have also added to the demise of your FPR. If you’re making the kind of power that requires a 255, upgrading your fuel lines and fuel hanger the the ProM one would be useful.

I hope the mains are okay too. I'm not sure how I will know if they arent...

Engine Car spewing fuel

silverlx50

7991LXnSHO

wanna catch the space herp

silverlx50

General karthief

wonder how much it would cost to ship you a pair

Mstng93SSP

You have a nice rear end there Dave.

7991LXnSHO

wanna catch the space herp

Dan02gt

mazing how much gas smell came from that tiny hole

General karthief

wonder how much it would cost to ship you a pair

silverlx50

silverlx50

General karthief

wonder how much it would cost to ship you a pair

Injector Cleaning - InjectorRx

silverlx50

silverlx50

Dan02gt

mazing how much gas smell came from that tiny hole

7991LXnSHO

wanna catch the space herp

silverlx50

silverlx50

silverlx50

Dan02gt

mazing how much gas smell came from that tiny hole

silverlx50

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Engine Car spewing fuel

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wanna catch the space herp

mazing how much gas smell came from that tiny hole

wonder how much it would cost to ship you a pair

wonder how much it would cost to ship you a pair

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wanna catch the space herp

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