have a 98 2.5 stick ran yesterday went to start it today all it does is turn over I checked and no power to the coils so no spark ,no power to the fuel pump ran a hot wire to the pump and it filled the rail all the dash lights work .cleaned the battery cables tried to start it with 400 amp boost still does not start

 

PCM relay or fuse? Might try swapping those around to see if the problem goes away. Only thing I can think of at the moment that would effect both the fuel and spark aspects.

 

I switched all the realys and checked all the fuses

 

Tractors, I'm not far from you. PM me if you'd like a hand trouble shooting. I have all wiring diagrams and stuff for your truck.

Greg

 

do I dare put the pcm from the 98 and put it my 04 4.0 and see if it will start my 04?

 

Don't do it. The PCM coil drivers, ignition timing, and EFI sequencing logic are different between a 4 cylinder and a V6 engine.

When you first turn the key to the "on" position, do you hear the fuel pump prime for 1-2 seconds?

There may be a pending code stored in memory even though there isn't a CEL. Try and get a code reader on there.

 

If you can jumper the fuel pump & have it run, then power to operate it isn't being switched by the fuel pump relay for some reason. Seeing as how you don't have spark either, sounds like the PCM relay isn't switchng powr either.

SO, do you have battery voltage to the under hood power distribution box, to be switched by the fuel pump & PCM power relays????

If not, the problem is likely in the wiring, between the battery & the distribution box, as the distribution box is suposed t be "hot" all the time.

If you have power to the ditribution box, but the relays aren't working, then make sure the in cabin/dash fuse panel fuses, for the fuel pump & PCM relays operating coils are ok & those fuses have power to them.

If the fuses are ok, but you still don't have power to the relays or their fuses, when you go to "run", or "start" on the ignition switch, then look between the ignition switch & relays for a wiring, connector, or ignition switch problem.

Let us know where you're loosing power.

Just some power probe thoughts, to try to narrow down the problem area.

 

I hooked up a reader and it said it couldnt find the pcm .

 

Look to the PCM power diode fuse, located in the cab fuse panel on the left end of the dash. On my 99 it's position 19 & 25 amp mini fuse.

If it checks ok, then look to the under hood power distribution box, located on the drivers side inner fender close to the firewall & check the Electronic Engine Controls Diode & make sure i hasn't opened up.

Then check mini fuse #6, the 10 amp fuse the PCM power relay. If it's blown, te PCM power relay won't work & switch power to the PCM.

If this fuse is ok, then test both sides of it's contacts for battery voltage. If that checks ok, then move to the PCM power relay & try thumping it & see if you can wake it up.

If not, try swapping it with the A/C power relay & see if the PCM will power up. If not, then do a voltage test to the relays solenoid contacts, to see if you have power to them, coming from the relays mini fue you just tested. You must have power to operate the relay & have it switch operating power to the PCM.

If that checks out & the relay is working, then check for battery power at the relays output terminals to the PCM, as it must have this switched power to operate.

It seems to me, because you don't have spark, or fuel pump & the scan tool says it can't find the PCM, the PCM isn't getting power for some reason. So check/test, or swap out, the PCM circuits fuses & power relay, to find out where power to the PCM is being interrupted.

Let us know what you find.

 

I changed #19 fuse and it started up the fuse looked good but it wasnt thanks for all your help

 

OK, good trouble shoot & feedback.

Good to hear it was a simple fix & your "On The Road Again"!!!!