got a 98 ford f150 4.2 2wd im in a bind here and figured someone mabey delt with somthing like this before .. i have no fuel pressure, no spark ,and no injector pulse ?? ive done some testing only to find question marks ????.. i jumped power right to the pump and the pump will run and build pressure just wont start still ..so i replaced it just to be sure could it be a eec ? im lost here its a customers car and dont want to waste his money hes a good freind ya know any help would be apreciated on what to test or check or mabey someone knows whats the deal from experiance please help gotta get this wrapped up got other cars to do !! PLEAAAASSE HELPPP HAHA

 

Might sound silly, but I,d start checking all the main fuses.

Got power to the computer?

 

Reset the breaker, it's blown. The inertia behind the passenger side kick panel. Just push to reset.

 

not the ineria switch ive replaced it its not blown and ive checked all the fuses already very wierd but thanks for the replays any other ideas ??

 

man 150 hit on this thread and only 2 poeple wrote back ? come on guys i know someone has some ideas for me i really need some help with this

 

crank sensor?

 

Any codes? Any communication with the computer? Does it have an anti-theft system at all?

 

cant pull codes up with my scanner it wont connect to it for some reason so i tested the diag port and it has power and my code reader gets power from it but its reading link error ?? it dosnt have a theft system that i know of unless its a factory installed but i doubt it its a very very base model truck ya know it seems like everything is dead no spark no injector pulse no power to fuel pump i just dont get it im not even sure were to start testing hah

 

ya could be .. but would that effect the fuel pumps operation ?? it could effect the injectors and ignition bieng able to wok properly i guess i could get one and try it out just dont know why the fuel is inop .. someone mentioned somthing about a eec could be bad ?? im a gm tech so im not to aure what the main function of a eec is on a ford any ideas ???

 

The EEC (PCM) does the same thing as it does on a GM - OBD2 is OBD2.

Have you checked the 175 amp maxifuses on the firewall? I think that has them.

 

That would be my next guess.

 

Being that your not geting any communiction with the computer (PCM, EEC) I would look at that since if it is dead it wont be telling anything to work, you might want to see if someone managed to unplug it. Did your friend have this truck sitting for some time or did this just randmly happen?

 

did it while he was at a stop light .. truck is drivin everyday .. how do you check a eec if it **** the bed or not just test it like gm for outputs and what not ? i also checked the big fuses all still good but i thank you for all the replys i think you guys are gonna be able to help me

 

It wont be the crank sensor. The pump will run with a bad crank sensor.

If it was me I would be making sure all the connections at the pcm (passenger side behind the battery box on the firewall) and wiring harness/s on firewall as well. If that fails look at the grounds. If that fails try to source a used pcm from either a 97 or 98 v6 with the same trans (auto/manual). There is no PATS (anti-theft) on the 97 or 98's.

By chance there isn't a blue superchip (or any chip) on the back of the pcm. They can cause problems like this if the contacts have not been cleaned properly or the chip wiggles loose.

 

Here is the basic power circuit to the PCM.
Fuse 19 powers the fuel pump through a relay and the inertia switch.
Fuse 30 powers the PCM relay through a PCM power diode as well as ignition.
You have a power failure at some point if everything seems dead.
There is a seperate engine fuse module.
.
It would pay you to get a copy of the HAYNES manuel and look at pages 12-20/21/22 at the power inputs to these circuits for the V6.
It's a bit difficult to keep trying run these circuits on a board.
Obviously no Power you can't look at the PCM for any info codes..
Scanner power comes from an outside source and often powered from the cigar lighter ckt so you might still see power at the data connector but still not get anything from the PCM.
Good luck.