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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 44403
Experience:  16 years experience
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I have a 1996 f150 xlt 5.8l ext cab with dual tanks (the

Customer Question

Hey I have a 1996 f150 xlt 5.8l ext cab with dual tanks (the front don't work and spews gas out). The check engine light is on and has codes p174 system too lean in bank 2 and p308 missfire in cylinder 8 also p1000 on board diagnostics incomplete. I have changed coil pack, distrubuter cap, rotor button, and plug wire on cylinder 8 within the past month. The spark plugs were changed at a automotive shop about 2 months ago. Please help
Submitted: 1 year ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 1 year ago.

When you say spews gas, are you referring to when fueling? if so then the tank vent is likely clogged or the anti slosh valve in the filler neck base is likely stuck closed.

Lean codes are normally caused by vacuum leaks, low fuel pressure, or a misfire. Since you also have a miss on cylinder 8. Lets verify the compression, spark, and injector pulse to it are good.

You want a excellent 5 star answer & I would like to be rated the same for providing it. Consider I don't know your skill level & I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies. Try your best to respond with good detail so I can do the same. I normally log in at 3pm and work late. A rating is required. Your rating me, what I type. I am not an employee of this website, nor have control over the fees or the time it took to get a response. If you rate negative or not at all you still paid, but I get nothing. I want you pleased with me and my efforts, so let me know if your experience here has come up short.

Thanks Chris

Customer: replied 1 year ago.
The gas spews out when its running. I don't fuel it because it don't work. from what I've read I believe what's happening is the leftover fuel that don't get used is sent back to the front fuel tank. Not really my main concern though, just figured I would let u know in case it could have something to do with the codes.
Customer: replied 1 year ago.
How long do I have to give u the results on the spark, fuel injector pulse, and compression test
Expert:  Chris (aka- Moose) replied 1 year ago.

We have 7 days to get this addressed and rated. if there is no rating before 7 days, then i no longer see your replies. Rated prior to 7 days and still working with me is not a problem. Are you able to run the truck only using the front tank?

Customer: replied 1 year ago.
No it won't start when on the front and when running if I switch to the front it dies out from loss of gas
Expert:  Chris (aka- Moose) replied 1 year ago.

Lean codes are normally caused by vacuum leaks, low fuel pressure, or a misfire. Since you also have a miss on cylinder 8. Lets verify the compression, spark, and injector pulse to it are good.

Can you check these things then we can address the front tank issues?

Customer: replied 1 year ago.
Ok I will get those results to u as soon as I can. Also I want to add that I can't hear it missing but when lightly accelerating inbetween 40 and 60 mph it starts shaking, bucking, or what have u, nothing too awfully bad. That's when it starts missing I believe. I read a lot about this and it seems to be a common problem with something in the ignition, which is all new, so not in my case I don't think. I've also read someone said it could be the dpfe sensor
Customer: replied 1 year ago.
Also read someone with the same problem said it was the fuel pump driver module. Said It collected grime over time and the computer chip inside that regulates fuel pressure was bad thus causing the misfire. I thought this sounded promising because of the extra fuel that gets sent back to the front tank
Customer: replied 1 year ago.
By the way I just got the vehicle about a month ago
Customer: replied 1 year ago.
I found this in front of the rear bumper driver side
Expert:  Chris (aka- Moose) replied 1 year ago.

Thanks for all the info you have gotten from blogs. Repaot back when you can on the tests I mentioned.

Customer: replied 1 year ago.
Ok fuel injector pulse good, spark test good, and compression test was about 120 but I found the spark plug had no gap so I gapped it to .30 and I believe that to be the problem because its driving better. So I just drive for 50 miles and the check engine light should go off on its own right?
Customer: replied 1 year ago.
If that was the cause of all 3 codes
Expert:  Chris (aka- Moose) replied 1 year ago.

You can disconnect the negative battery cable for 5 minutes to erase the code to see if it returns after 4 starts and drives. 120 psi is low, can you check a couple other cylinders?

Customer: replied 1 year ago.
Ok check engine light off and I tested compression again on cylinder 8 this time with the fuse pump relay out and wire from coil pack unplugged then cranked for 10 revolutions and got right under 180. So I believe I'm good to go. Just got that front fuel tank that don't want to work. I siphoned probably a quart or so out a few days ago probably 50 miles and don't think its spewed anymore out since
Expert:  Chris (aka- Moose) replied 1 year ago.

That is good compression.

Below is the wire diagram so you can test the selector and wiring to the pump and pump to see if the front pump is or is not getting power. The front tank will refill from using the rear tank through unused fuel returned by the pressure regulator. Its however overfilling because the front tank should be emptied first before switch over to the rear tank, and your not able to do that because the front tank has no fuel pressure.

Customer: replied 1 year ago.
Is there anyway I could skip all that by just crossing a line or block one
Customer: replied 1 year ago.
I want the unused fuel to go back to the rear tank and just forget about the front
Expert:  Chris (aka- Moose) replied 1 year ago.

You could I guess route the return hose to the rear tank and bypass the front tank. I have never tried or done that though.

Customer: replied 1 year ago.
I don't reckon you could give details or have any helpful pics or diagrams on that would you
Customer: replied 1 year ago.
Also that pic I sent you of the 2 plugs that were unplugged I found on my truck in front of rear bumper driver side could you tell me what it is
Expert:  Chris (aka- Moose) replied 1 year ago.

Unfortunately the age of the vehicle prevents that. Ford purges the non common repair guide pictures after 10 years to free up disc space leaving on the text in the repair guide which is virtually useless without the pictures.

I would need to know the wire colors and where the wires end, meaning what they connect to. All connector views under 5 wires are also deleted from the diagrams.

Customer: replied 1 year ago.
Can I help me find the return hose anyway with a diagram of the fuel lines or something
Customer: replied 1 year ago.
You*
Expert:  Chris (aka- Moose) replied 1 year ago.

On the injector rail is a fuel pressure regulator. The fuel line connected to it, is the return to the fuel tank. Follow that line to the fuel tank.