94 f150, 4.9 I6 wont start! help!
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94 f150, 4.9 I6 wont start! help!
okay this thing has been being a bastard for quite some time now..
whats been done;
new plugs, wires, ign module, dist. cap rotor, the whole ingnition is new...
fuel filter, checked all hte fuel pump fuses relays
are there 2 pumps on this thing? if so what are the chances one is bad? i can hear it run for a few seconds when i flip the key, but i would think it would keep running until it builds up pressure, i can flip it on and disconnect the line at the filter and there is no pressure on it... just some gas in there
im assuming there is another filter on the bottom of the pump in the tank, could that get clogged enough to choke the whole truck? i mean it wont even gurggle one bit, it just sits there and cranks....
help!!!
whats been done;
new plugs, wires, ign module, dist. cap rotor, the whole ingnition is new...
fuel filter, checked all hte fuel pump fuses relays
are there 2 pumps on this thing? if so what are the chances one is bad? i can hear it run for a few seconds when i flip the key, but i would think it would keep running until it builds up pressure, i can flip it on and disconnect the line at the filter and there is no pressure on it... just some gas in there
im assuming there is another filter on the bottom of the pump in the tank, could that get clogged enough to choke the whole truck? i mean it wont even gurggle one bit, it just sits there and cranks....
help!!!
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Joined: Dec 2002
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From: Fairfax, VA
Need more info. What led up to the truck dying? Were you driving down the road and it just crapped out? Is the inertia switch tripped?
It might have two pumps. If so, one will be in the tank, and one on the frame. Get under there and trace the lines from the tank.
How exactly did you check the relays? Did you bypass the relay and run the circuit hot, or use a relay checking device?
Don't laugh, but does it have gas in the tank?
There is a strainer for the in tank pump, but the chances of it clogging so bad that no fuel at all passes through are very slim.
I have seen situations where everything checks out, but still no fuel pressure. Dropped the tank and found that a soldered connection at the pump had come loose. Even heard the pump cycle on and off while checking it out.
SL
It might have two pumps. If so, one will be in the tank, and one on the frame. Get under there and trace the lines from the tank.
How exactly did you check the relays? Did you bypass the relay and run the circuit hot, or use a relay checking device?
Don't laugh, but does it have gas in the tank?
There is a strainer for the in tank pump, but the chances of it clogging so bad that no fuel at all passes through are very slim.
I have seen situations where everything checks out, but still no fuel pressure. Dropped the tank and found that a soldered connection at the pump had come loose. Even heard the pump cycle on and off while checking it out.
SL
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heres the story; its my brothers truck
it used to just die randomly going down the road, eventually it would restart and be ok, so he took it to some national tire and battery or something where they charged him like 500 dollars for wires, plugs, cap,rotor, and distributor... it still did it... eventually it just wouldnt start at all..
he had it towed to a local garage, the guy looked at it and said it had spark, had fuel, he guessed it was hte ignition module... though he never fixed anything.. it got towed back to my brothers house where it sits now
i went down and threw an ignition module on it, and tried to start it... it chugged for half a second and died again and wont start at all.. i put on a new fuel filter and still nothing, there doesnt seem to be much pressure in the lines
i did not see a 2nd fuel pump anywhere but i did not look that thoroughly, there is a 2nd fuel line going to the engine that says "high pressure fuel" on it, this line is not the line that the filter is on..
inertia switch? im not sure what you are referring to, where is that located?
how i checked the relays- i switched the headlight or radio (i forget) relay and the fuel pump relay since they were the same and thats as far as i went, it made no difference, like i said you can hear hte pump run for 5-10 seconds when you flip the key on, but thats it, even with the fuel lines unhooked it does not keep running
yes there is gas in the tank
i was going to drop the tank and just take that to be looked at somewhere, but thats all i can even think of now?!
thanks for the help!
it used to just die randomly going down the road, eventually it would restart and be ok, so he took it to some national tire and battery or something where they charged him like 500 dollars for wires, plugs, cap,rotor, and distributor... it still did it... eventually it just wouldnt start at all..
he had it towed to a local garage, the guy looked at it and said it had spark, had fuel, he guessed it was hte ignition module... though he never fixed anything.. it got towed back to my brothers house where it sits now
i went down and threw an ignition module on it, and tried to start it... it chugged for half a second and died again and wont start at all.. i put on a new fuel filter and still nothing, there doesnt seem to be much pressure in the lines
i did not see a 2nd fuel pump anywhere but i did not look that thoroughly, there is a 2nd fuel line going to the engine that says "high pressure fuel" on it, this line is not the line that the filter is on..
inertia switch? im not sure what you are referring to, where is that located?
how i checked the relays- i switched the headlight or radio (i forget) relay and the fuel pump relay since they were the same and thats as far as i went, it made no difference, like i said you can hear hte pump run for 5-10 seconds when you flip the key on, but thats it, even with the fuel lines unhooked it does not keep running
yes there is gas in the tank
i was going to drop the tank and just take that to be looked at somewhere, but thats all i can even think of now?!
thanks for the help!
Last edited by seth ferguson; Apr 19, 2005 at 12:41 PM.
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Joined: Apr 2005
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i had this same problem on my 88. i think it has to do with the fuel pickup in the bottom of the tank. mine was a single inline fuel pump with duel tanks. i replaced nearly $200 worth of parts including the fuel filter, and pump, full ignition and ran open throttle bodies too to make sure it wasnt choking. my truck would startup, drive for 3 minutes then either stall or almost stall, then after 10 seconds would start back up again and drive for another 3 minutes. it was really noticable at typical nominal speeds (30-45-60) while maintaining a constant throttle percentage.
however, i went to replace the tanks in the 88 and found my sender tubes were nearly rotted through, the tank was shot anyway, so i decided, $300 in parts to fix that? or $400 to buy a newer truck with a bad motor that had a good tank, newer body, and way less rust. i went that option. anyway, turns out the 88 motor in my now 92 runs fine, and i didnt change anything off the motor while doing the swap. so what im saying, now that my motor has a new tank and a clean strainer, it runs great. so check into that. if your tanks are rusted, the rust collects at the bottom and can clog the strainer.
even if your truck doesnt have an inline fuel pump, ts not a bad idea to add one for ****s and giggles as an auxillary.
good luck man.
however, i went to replace the tanks in the 88 and found my sender tubes were nearly rotted through, the tank was shot anyway, so i decided, $300 in parts to fix that? or $400 to buy a newer truck with a bad motor that had a good tank, newer body, and way less rust. i went that option. anyway, turns out the 88 motor in my now 92 runs fine, and i didnt change anything off the motor while doing the swap. so what im saying, now that my motor has a new tank and a clean strainer, it runs great. so check into that. if your tanks are rusted, the rust collects at the bottom and can clog the strainer.
even if your truck doesnt have an inline fuel pump, ts not a bad idea to add one for ****s and giggles as an auxillary.
good luck man.