1988 F250 7.5L engine issues
 

Brief back story:

Truck is an old tired farm truck that I have been working on to bring it back to life. It is a family treasure so throwing a match on it isn't an option.

The truck would start and run great up until a few months ago. In October I took all the front fenders, grill and hood off to replace them with something nice. At the time I took pictures of the solenoid wiring and the wiring harness in general.

With the fenders off I tried to start the truck so that I could move it out to the pressure washer. It would crank but wouldn't start. Moved it around with a chain and didn't think about it anymore.

Fast forward to now: Truck turns over fine but no fuel pressure.

List of checks and fixes:
New battery
Solenoid replaced
New positive and negative battery cables installed
checked for spark at distributor
replaced fuel pressure module
replaced ignition switch
temporarily hard wired rail fuel pump and it came on and fuel pressure looks good at the shrader valve on top of engine.

After all of that the engine turns over fine and the starter sounds good. I'm still not getting it to start even with the fuel pump hard wired.

After reading multiple threads it seems like my ECM might be fried. I will remove it and order the replacement.

Is there anything else that you guys can think of that I might be missing??

I have even considered spending the money to replace the entire engine wiring harness but both Painless and EZ Wiring have told me that complete replacement kits aren't available. Buying a used one isn't something I want to do. I would rather replace/build a new harness as necessary.

Please help if you can. I'm hoping to have this truck back on the road this spring but I'm getting frustrated with this issue that I seem to have caused when I pulled the fenders off and tried to start it.

Thanks

When you disconnected the ground at the right hand fender you probably lost the ground for the PCM (computer) and a few other systems. At the very least tie those leads back to the negative terminal on the battery.

G101:
https://www.supermotors.net/getfile/...und-g101-2.jpg

X2 on this...

Thank you both for the quick replies.

Currently I have those leads on the positive battery side of the solenoid?? From memory that is where I remembered them being when I took the fenders off. The only thing I remember disconnecting from the fender was the solenoid bolts.

Should I move these leads and try again?

One other question; is the PCM next to the Fuel pump module on the driver's side by the air cleaner box?

PCM location courtesy of subford:
http://i54.photobucket.com/albums/g9...CMlocation.jpg

Start by checking if there are smaller leads coming off the negative side of the battery. That photo came from a 1990 Bronco. Sometimes Ford moves grounds around a bit, but obviously they kept they PCM ground in the same location from 1990 and later trucks. More than once I found out a connector on an earlier model was in a completely different location.

Does PCM stand for Power Control Module? I asked at Oreilly's and they couldn't find anything on their computer.

Tonight I will pull the computer and get it a new one ordered. Might as well while I have everything torn apart.

I'm going to take some pictures this evening and get them posted up. Hopefully that will help everyone make sense of the mess I have on my hands.

Thanks again for the advice.

Duplicate post..

As others stated, get those leads to a good Ground. PCM may be perfectly fine and you won't know if you get another and swap for core.

Post pics of the front clip area and those leads you said ate tied into the positive.side. Let's try to work on a budget and not throw money away.

Will do.

I can appreciate working on a budget but making it run correctly and my wife not calling me stranded is priceless.

Ugly pictures to follow this evening.

Have a nice day

PCM= Powertrain Control Module, correct. It refers to the EEC-IV computer.

so the module sends power to the EEC computer? I guess I need to check for power at the EEC and check if there is any resistance in the wire between the module and the computer?

The grounds talked about above should run from the NEG post of the battery to a plug C104.

Make sure the small black wire with a green stripe has a good ground there. That wire is the Computer ground wire going to pins 40 & 60 on the ECM Computer.
I do not think the Computer controlled the transmission in 1988 so it was not a PCM but an ECM Computer. They may have it list as a EEC Computer also.

G203 is at the right hand side (passenger side) of the engine block.
http://i54.photobucket.com/albums/g9...ps30dd35da.jpg

/