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I was thinking about this more last night. Since you die when you switch to the rear tank, even if it's been running for a while on the front (so you already had prime on the fuel lines), that suggests that the check valve in the rear tank is stuck partially open, but closed enough to starve the pump. I wonder if some debris got stuck in it.
I don't know if the pumps are interchangeable between the two tanks, probably not since the heights of the tanks are different, so the pickup tube and the fuel sender arms would have to be different at a minimum.
Yeah, that vent valve was fun to install on my rear tank a while back. Someone had the rear tank replaced, and they used the old vent valve. However, they didn't get a new seal for it and used Permatex grey, which isn't rated for gas. First time I filled up I got a few gallons on the ground. The sealant looked like chewing gum.
So upon testing there was a bad fuel leak - seems the main fuel line for the rear tank was pierced in 3 places, fixed that today, went for a test drive.
No Leaks but - The motor hesitates on the rear tank, fine on the front. In P the motor will run fine, and will rev smoothly, but in Drive will hesitate and if I touch the gas will even stall (flooding the motor?)
Any advice appreciated at this point as its got me stumped.
If it's a fuel pump issue, then you'd be running lean. The injectors could flood the engine, but I don't see how the pump would. Likely that the fuel pump is only giving you partial pressure.
If it's a fuel pump issue, then you'd be running lean. The injectors could flood the engine, but I don't see how the pump would. Likely that the fuel pump is only giving you partial pressure.
brand new pumps front and rear. Tbf I only tested the rear at idle when i found the leaks but had run out of time. Today was the first opportunity to resolve. Had to replace parts of both rear lines
I'd say you should probably get a fuel pressure gauge and test both pumps to see what they're building up to. I think the auto parts stores have them as one of their loaner tools.
OK both pumps tested - both over 10psi each (gauge only goes to 10) and equal.
So assumed it was bad gas - drained the tank
This is the gas that was in the rear tank...
Added 5 gal of fresh and some injector cleaner - still doing it.
Am completely stumped
2 new pumps, no leaks, good pressure on both pumps, hesitates/dies on the rear with load - will idle no problem, but give it some peddle and it will stall.
Vapor locking the tank? I'd assume it would take a while of running on a tank to get to that point if your vent was bad.
Since it will idle fine but dies under load, have you tried running it for a few minutes at a higher speed, but not in gear?
yeah so if I press the throttle that’s when it hesitates and dies, if I lift off before it’s completely dies it will recover and idle but will eventually die anyway… new pumps and new vent seals…
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