Good evening and happy holidays -

98 F150 5.4 4x4 155,000 miles

Well it all started this morning on my way to my favorite duck hunting spot. I had just gassed up and headed down the freeway. The ol'ford started to miss like a bad COP and CEL was turning on intermitantly. I turned around and went home to get my scanner to find out the problem. I was unable to pull any codes but i cleared the PCM anyways. I drove around after this for couple hours, no more codes,and the truck was driving very smooth.

I decided to go back out duck hunting. After 10 or 15 miles at 75/80 mph, the truck just died with a solid CEL. This time i kept the scanner in the truck but the scanner was returning an error indicating communication error (display read check the connection) thus no codes again.

I attempted to restart the truck and it would turn over but it sounded like it was out of gas. I had to call my dad to tow me home. This is the first time my ol'ford has left me stranded and to add insult to injury i was towed home by a chevy.

After doing some research, I think I have limited my possible issues
1. PCM fuses
2. PCM fried
3. Faulty fuel pump
4. Fule pump fuses

Since it is late and raining outside, I will start my trouble shooting tomorrow but If anyone has experienced these symptoms please offer your input - as always it is greatly appreciated.

 

Sounds waaaaayyyy too much like a alternator, buddy of mine has a 98 4x4 4.6 and just replaced one, battery too but I think just cause on that. It worked for him longer before it just went kaput. Pretty sure he had the battery light come on too. Just rule that a possibility.

 

Sounds like a fuel filter as well .

Easy to tell if it's the fuel pump - you should be able to here it charge the line - ignition in run position before start. - I have to say , my 98 pump went out at the same milage you have - way back when lol.

It might be a fuse NOW - since it won't start. Mine acted funny before the pump locked and blew the fuse. If the fuse is wasted , that's not the root cause.

You can just about rule out #1, #2 and #4 - I seriously doubt those would be the root causes.

BLUE20004X4 mentioned a good posibility as well.

You'll figure it out pretty quick I bet.

 

Specifically, check F24 and F30. Both have been commonly found to be blown due to short circuits and will cause your symptoms. Since your scan tool will no longer communicate, you can be certain that this is an electrical fault, not a fuel filter.

If the engine cranks, the alternator also is not at fault since the battery would have been dead from a "no charge" condition.

If F30 is blown, check for shorted RFI caps.

If F24 is blown, look for O2 sensor harness that are melted on ehaust components or that have rubbed on moving drivetrain/suspension components.

Steve

 

Thank everyone for your input.....

It turned out the little negative cable ground to the firewall was loose. I tightened and alls well.\

I did test all fuses and they were all fine. I also took the truck to autozone to test battery and alternator - both checked out fine.

I drove it 60 miles - went duck hunting - and she drove just great.

thanks again for everyones expertise!!!!!!

Happy Holidays :santa:

 

How is that possible ? You have anything else as to how you determined ?

I'm pretty sure what cable - There only one comming from the manifold , but mine ran without it ????

Never heard of this one - are you sure?

 

I dont know for sure, but thats the only thing i did to truck this morning. It could have been a fluke, but i cant explain how my truck started up this morning.... Trust me i was completely shocked. I had planned on working on my truck all day. I guess i could try to recreate the syptoms by disconnecting the cable and see what it does.

I just hope it does erase my radio stations

 

Yeah, that would be cool if you could do that, because that wasn't quite the solution I would have pictured either...

 

Will do 98Lariet4x4, but it might be a day or two because of the holidays. I will post the outcome of disconnecting the cable.

 

You don't have to go out of your way lol. If the prod crops up on yuh again just post back here.

Thanx.

 

Probably the one right above, and behind the top of the battery on the firewall. That's a major ground. That's the one that grounds the cab (and thus the PCM). It's also the one we always upgrade to 0 gauge for running big amps that ground to the cab. There's one more ground that comes off the negative, but I can't recall where it goes off hand. I'll look tomorrow and post it.

 

I thought he was talking about that green one -

 

hey do you know where the green one connects to? i broke mine ansd cant see where it went