Starts on one tank / runs on the other
01-11-2018, 11:02 PM
#1
Member
Thread Starter
Starts on one tank / runs on the other
Hey guys.
This one has me stumped.
1996 f150
300 i6
New rear fuel pump
New rear tank.
New tank selector switch.
All 3 were found to be faulty
Now, with two completely full tanks of fuel,
Truck will only start if I have front tank selected, but it then dies right away.
BUT, if I switch to rear tank just after it fires up, she keeps running fine.
The kicker is... it won’t start on rear tank alone..
So I am mobile, only on rear tank, but every time I start the truck, I have to set it to front tank, crank until it grabs, then quickly switch to rear tank to keep it running. Runs great the entire time otherwise.
Ideas??
This one has me stumped.
1996 f150
300 i6
New rear fuel pump
New rear tank.
New tank selector switch.
All 3 were found to be faulty
Now, with two completely full tanks of fuel,
Truck will only start if I have front tank selected, but it then dies right away.
BUT, if I switch to rear tank just after it fires up, she keeps running fine.
The kicker is... it won’t start on rear tank alone..
So I am mobile, only on rear tank, but every time I start the truck, I have to set it to front tank, crank until it grabs, then quickly switch to rear tank to keep it running. Runs great the entire time otherwise.
Ideas??
01-12-2018, 01:39 PM
#2
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Join Date: Jan 2018
Location: Memphis, TN, Earth, Milky Way
Posts: 11,256
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That's not much description of the truck, its options, or its history. Click this, read the caption, & fill in your signature here with ALL its details:
(phone app link)New Ford/MotorCraft, or new Spectra/Airtex? Who installed them? How long ago (time & miles)? Did each one pass the same tests that the previous ones failed?In exactly what way, for EACH part? By you, or by some shop you took it to? It's highly unlikely for a switch to fail at exactly the same moment as a pump and a tank; and it's even-less-likely for the truck to keep running when either one of them fails, long enough for the other to fail. So it sounds like someone was throwing part$ at it.Full just looking at the gauge? Or full until the pump clicks off? Or full after rocking the truck, and seeing gas standing in the filler necks? What happens to each tank's level if you just drive a few hundred miles without stopping for more gas?
So exactly how long is "right away" that it gives you time to switch tanks?Does it sputter & cough like it's trying to fire up, or does it just spin steadily without running?Put a fuel pressure gauge on it, and check each tank. Don't buy or change any more parts until you KNOW what's wrong.
(phone app link)New Ford/MotorCraft, or new Spectra/Airtex? Who installed them? How long ago (time & miles)? Did each one pass the same tests that the previous ones failed?In exactly what way, for EACH part? By you, or by some shop you took it to? It's highly unlikely for a switch to fail at exactly the same moment as a pump and a tank; and it's even-less-likely for the truck to keep running when either one of them fails, long enough for the other to fail. So it sounds like someone was throwing part$ at it.Full just looking at the gauge? Or full until the pump clicks off? Or full after rocking the truck, and seeing gas standing in the filler necks? What happens to each tank's level if you just drive a few hundred miles without stopping for more gas?
Last edited by Steve83; 01-12-2018 at 01:42 PM.
01-12-2018, 02:54 PM
#3
Martin
Have you tried using the original selector switch?
My recent fuel pump experience. Replaced rear pump. Could hear pump running but truck wouldn't start or run using it. Built a test electrical plug that reversed the wiring and it ran fine. Being as the wiring on new pump is one red and one black wire, I know it was wired correctly. I'm not the sharpest tool but not that dull either.
I included this little history just to say strange things happen. In my case I called a mechanic friend that suggested what he thought was my problem, it had me stumped.
My recent fuel pump experience. Replaced rear pump. Could hear pump running but truck wouldn't start or run using it. Built a test electrical plug that reversed the wiring and it ran fine. Being as the wiring on new pump is one red and one black wire, I know it was wired correctly. I'm not the sharpest tool but not that dull either.
I included this little history just to say strange things happen. In my case I called a mechanic friend that suggested what he thought was my problem, it had me stumped.