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Fuel delivery issue---Help!!

I have a 1988 F-150 4x4 with the 4.9L inline-6 and manual tranny. I recently replaced the timing gears and when all was reassembled, i found i was getting no fuel. When i ground the the fuel pump slot on the diagnostic connector, the truck will run but it will not idle and if i unplug the shunt the engine will race a bit as if i just leaned out the mixture and then dies immediately. I have replaced the fuel filter and fuel pump relay but this has not changed the situation. The truck has dual tanks with in-tank passive pumps and an in-line high-pressure pump on the frame rail. The truck IS in time, running smoothly (if a bit loaded-up sounding) as long as the shunt is in the diag. connector. Any suggestions as to what to try next will be greatly appreciated since i am now beyond the limit my technical expertise...(way beyond...) Thanks

Reply to
robbinsjr1
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What is the spark timing when you have it running, shunted?

I think you have more than one problem, but start there.

Reply to
Backyard Mechanic

Timing set at 10 degrees BTDC according to Alldata.com specs (the emissions sticker is gone from the engine compartment). I dont know what it is without the shunt because it dies within about 3-4 seconds after removal but i am sure i can manage to find out. Will post as soon as i get it.

Reply to
robbinsjr1

No... doesnt matter.

Want you to see what the timing is with the FPRelay shunt in so to keep it running.

If it's 10 deg with the SPOUT connector installed or not, that tells us something. That the timing pulse isnt getting to ECM.

You didnt mention if Fuel pump ran at key-on cycle

Reply to
Backyard Mechanic

Doooohh. no sooner posted that than I realized you wouldnt be getting injector pulses if no spark signal to ECM Would hurt to check anyway.. but I think we need to know if FP runs initial key-on

Backyard Mechanic wrote:

Reply to
Backyard Mechanic

Reply to
robbinsjr1

Well, that spout-in timing doesnt sound right.. but I'm thinking you have a problem with your tank selector/relays/solenoids

And I dont know where they are.

Reply to
Backyard Mechanic

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