boatbum
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boatbum
! I have a 89 f150 4.9 6cyl efi twin gas tank, 90000mile-- Well I have 2 problems, first my motor starts missing (bad) after it warms up ( i am showing low fuel pres. when it starts missing) and second my fuel tanks will not switch. It shows the front tank when I switch but will not take gas from it. I have replaced the back tank and the filter,and fuel pumps lo and hi. I have replaced all the sensors (including map and thurmostat )and next the computer box and dist.with its imc that fits on it. it has new wires plugs and cap and rotor, and coil, I just can not find the problem ? I am ready to shoot it but then I would have a bigger problem LOL It runs great till the motor gets to temp. then runs like ship!
any one got a thought ???? THANKS boatbum
any one got a thought ???? THANKS boatbum
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Thanks for the help !
I changed the 2 relays for fuel pump and pc box first then I put a a new ford icm on a new distributor on but it still dies when hits run temp,,, next I put a new PCM box in and a coil. Still no change. Next I put a Hi press fuel pump and filter on (d.s. under the truck). still no change, Next I put a new rear fuel tank with sinder and new low press. pump in and still no Change, I have ordered the dual function switching(6 port) bowl( Driver side on Frame rail by door) that is used to change fuel tanks, should be here Fri. I found no electric solenoid on frame the repair book has tank switch by pressure in 6port bowl), I am getting around 40 lbs on a fuel press tester at the fuel rail so i would guess the pressure regulator is working ok! But I did see a drop in fuel pressure when the motor gets warmed up and starts missing. ???? I am trying but this truck is killing me LOL ! Thanks boatbum
I changed the 2 relays for fuel pump and pc box first then I put a a new ford icm on a new distributor on but it still dies when hits run temp,,, next I put a new PCM box in and a coil. Still no change. Next I put a Hi press fuel pump and filter on (d.s. under the truck). still no change, Next I put a new rear fuel tank with sinder and new low press. pump in and still no Change, I have ordered the dual function switching(6 port) bowl( Driver side on Frame rail by door) that is used to change fuel tanks, should be here Fri. I found no electric solenoid on frame the repair book has tank switch by pressure in 6port bowl), I am getting around 40 lbs on a fuel press tester at the fuel rail so i would guess the pressure regulator is working ok! But I did see a drop in fuel pressure when the motor gets warmed up and starts missing. ???? I am trying but this truck is killing me LOL ! Thanks boatbum
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reply I found problem
From boatbum!
It was a bad wire on the dash gas tank fuel switch. I put a lot of parts in but would no longer run at all. I checked for Spark and it was good, I took off my hi pres. pump and it would suck gas from a plastic cup up to the pump, bot there was no gas coming to it. So It looked like a bad low pres. intank pump, or pumps as I have 2. Feering replacing these as Pulling tanks sucks I traced the 6 wires at the on the dash switch. I found no power at the tank motor wire, I did a quick jump for power and the truck charged the fuel lines and started but Ran great. I took it for a long ride and things are A ok. HOPE THIS HELPS Some one boatbum
From boatbum!
It was a bad wire on the dash gas tank fuel switch. I put a lot of parts in but would no longer run at all. I checked for Spark and it was good, I took off my hi pres. pump and it would suck gas from a plastic cup up to the pump, bot there was no gas coming to it. So It looked like a bad low pres. intank pump, or pumps as I have 2. Feering replacing these as Pulling tanks sucks I traced the 6 wires at the on the dash switch. I found no power at the tank motor wire, I did a quick jump for power and the truck charged the fuel lines and started but Ran great. I took it for a long ride and things are A ok. HOPE THIS HELPS Some one boatbum
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