First let me say that this is one great forum. Lots of good heads here.

My problem: My 1997 7.3L suddenly started severe missing while pulling my 5th wheel across Wyoming. I dropped from 70 mph down to about 25 mph and it quit missing. Not wanting to be stranded I replaced the fuel filter. It had about 10,000 on it. Also I opened the fuel water drain just in case it was water. All went well for another 2000 miles. Then the other day, I was driving with out the trailer and it did it again in exactly the same manor. I am baffeled. Any ideas?

Thanks.......Don

 

WAG = Bad fuel??
Did you replace the filter again?
Drain the housing, see what comes out.

 

have you cleaned the fpr screen?

 

What is the fpr screen? Where is it?
Only changed fuel filter once.
If it was bad fuel, wouldn't the problem be more constant?
& thanks for the quick response.....Don

 

under valve cover harness......

 

the fpr screen is in the fuel filter bowl your have to take the filter out and drain some fuel out to see it, its on the side of the housing there be a small hole. just use a q-tip with the cotton taken off to gently scrape the crud off the screen.

 

I would also listen to what coonhunter joe is saying and at least check the under valve cover harness. A neighbor of mine had the exact same problem as you have and he chased it forever and even the local crappy FORD garage couldn't fix it, they wanted to replaced the whole engine. Finally he asked me to look at it, so I removed the air filter assembly and everything I could to get to the UVC harness connections and sure enough I could stick my head down there by the harness and smell the burnt connection.

It is a very easy test and will save you a lot of chasing if that is what it is. You have to remove a few things to get down there to them, but once you can get close enough , you can just sniff the connectors (once pulled loose) and even sniff in the area of the UVC Harness and you should be able to smell the burnt electronics/plastic smell if they are bad.

I know it sounds wierd but it is a really easy test to see if they are bad.

You could also pull everything off to get to both sounds of the harness and check it for continuity across all the pins, but I have yet to find one that is bad that didn't have the burnt smell that let me know that I needed to go ahead and pull the valve covers and replace the UVC harness.

hope that helps

 

Does the check engine light come on while its acting up? If not its unlikely to be a wiring issue.

 

I meant both sides here , not "sounds" as I typed. I mist have been listening to the wife ramble while I was typing. I have a bad habit of typing what someone is saying instead of what I mean to type, if someone is talking to me while I am typing. I guess it would be a handy trait if I was a dictationist.