Troyphy truck

[M4wdFab]

if it fires on fuel dumped into it that means the PCM is at least functioning and preparing for a start-  you could stick a DVM into one of the injectors harness plug to verify power is being sent to open them (meter will just bounce, but if it does nothing then no power) 

if you get some kind of bouncing voltage to an injector, start tapping on the side of the injectors with something while cranking or feeding it with carb shot.  im guessing this thing sat so long they are just stuck.  you can also pull the rail and crank it to see if they are spraying (be carful)




i

[mr.mindless]

usually no feedback there. but did you jumper the crash switch? I think it kills the fuel pump not the injectors though. check computer ground and check injector power?

[luvmyxj]

usually no feedback there. but did you jumper the crash switch? I think it kills the fuel pump not the injectors though. check computer ground and check injector power?

i still have entire wiring loom for body and have donor truck steering column plugged in to make sure i had key on power, i found the + for fuel pump and ran a wire to it, now fuel pump comes on and pressurizes with key on and i checked the inertia switch and it shuts off when activated. i m pretty confident i have all grounds connected , but not sure how i would check if the computer has power. i have 2 red/white wires from 42 pin engine harness to injectors/ sensors etc that i have no idea where they go, looking for wire diagram to see if they possibly need 12+

[M4wdFab]

if it runs on starting fluid, then the computer is hot and working.  it wont make spark if its not happy with crank signal and maybe another thing or two.


still id go for making sure fuel is coming out of injectors and injectors are not stuck.  very common with sitting for years

[luvmyxj]

i have a feeling your prolly right, might be worthwhile to just get a new set of injectors, $40 on amazon

[luvmyxj]

New injectors in, still no vroom vroom. Still will start on manual fuel power. Still have to check voltage at injectors. Hmm maybe timing or PIP sensor after that?

[M4wdFab]

did you crank with the rail off the engine and confirm the injectors are spraying fuel?

it must be fuel or injector related, if it runs off starting fluid




assume fuel is not 9 years old in the truck supply?

[luvmyxj]

These injectors aren't held to the rail by typical clips, the rail fastens down on top of them, as soon as you add pressure it pops the injector out

[luvmyxj]

Am I doing this correctly? Multimeter set at 20v, red in injector harness ,black grounded, key on sits at .11v and when cranking jumps between .25-.35v

[M4wdFab]

2 wires to injector, one might be hot all the time, as they are usually ground side driven in the ECM, regardless probe both wires on injector harness plug) and you should see jumping on meter when cranking.   (dont attempt to use a chassis ground- could hurt meter or hurt ECM)

the meter isnt fast enough so it will try to average and give you a garbage voltage reading but the point is that you are seeing a voltage pulse or just seeing a constant zero volts.  A jumping meter or voltage pulse of any kind likely means the ECM is calling to open the injector properly.


while you have the injectors unplugged you could also check resistance between the two pins on each injector- should be something like 1.5, 4, or 12ohms.   all should be same value around there.  if any way high, way low, or open- bad time. 

 

[mr.mindless]

pretty sure I didn't pay $25 when I bought this 3 years ago, but it's super useful for exactly this sort of testing. even has mini points you can jam into the connector.

I haven't seen it in a while - probably in Joe someplace.
https://www.amazon.com/Lisle-27800-Universal-Noid-Light/dp/B0002SR57Q

[luvmyxj]

Found one for $14 ,ordered.
So if the red wire is hot ,where does that typically come from? Pcm? Or another source, on a Ford forum guy says there's a 3 prong plug that has 2+ 1- for injector power, but I have no such plug. Is there a way I could hot wire 12+v to them?

[mr.mindless]

on our Rangers it comes from ignition power, IIRC. there's a bundle of wires to tie into switches +12 and it's basically injectors, PCM power, fuel pump, alternator.

not sure how much those have in common with your BIG MOTOR

[luvmyxj]

noid light came and confirmed no power at the injector
had a few hours to kill so ran to j&j and picked up a eec and chassis harness and no change, threw a new ignition coil and map sensor at it and still no change, kinda lost now, should i throw a new distributor at it?

[mr.mindless]

Distrib won’t affect injector pulse unless the dist is where the computer senses cam/ crank position.

No cam/crank pos will lead to no injection though. That might be the next thing I’d chase.