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
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.
No... doesnt matter.
Want you to see what the timing is with the FPRelay shunt in so to keep
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
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
6 degrees BTDC with SPOUT sensor out, bumps itself to 10 with SPOUT in,
and yes, the high-pressure inline pump on the frame primes itself at
key-on although i cant hear whether the selected in-tank passive pump
is priming. With the shunt in, all 3 pumps run simultaneously, although
according to the never-wrong Haynes manual <insert sarcasm here>, only
the selected in-tank pump should run.
Backyard Mechanic wrote:
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