Ive been having problems with my 97 ford. it has 187,000 miles on it and it doesnt have much power. at times it will act like its missing on 2 to 4 cyl. if i push the throttle over half way its really starts to miss and run rought but up till then it runs good and smoth. I replaced the fuel filter and it didnt help at all. had it to a local shop and they put 3 injectors in it but it still dosnt run any better. they came to the conclusion that it needs the main wireing harness replaced????? also when in netureal if i floor it it will rev hard up to 2200 then stumbles, misses and creeps up to 3200 and blows blue smoke. just wondering if anyone has any ideas of things to try.
Thanks

 

Under valve cover harnesses. (UVCH)

 

They replaced both of them back in january when it acted up the first time, sorry i forgot to say that in the first post. I also should add i got the pickup back in 09 with around 132,000 on it and in my opinion it has never had the power that any other 7.3 early powerstroke had had that ive been around.

 

Check the fuel and filter in the bowl, see if it is black or if it is clean. If it is black, it could be injector o-rings on the ones they didn't replace.

 

when i changed it back in january it was really dirty and black. didnt run at all better with a new filter tho...... if the o rings are out why would that cause it to run so bad? looses compression? and why does it act up so much when it gets over half throttle?

 

That 2200rpm stumble I think is indicative of inj-o-rings. Black fuel filter is indicative of inj o-rings...I am thinking you need injector o-rings. I would do ipr o-rings at the same time. If they are original,save yourself the hassle and do them.they are cheap!
You can also start the engine with vc's off.Look at the inj bases where they go in head for oil bubblig out oil.

also remove idm and shake to check for water.

 

with the stumble and black filter sounds like injector o-rings, is the check engine light on?

 

Another vote for injector orings

 

No the check engine light never comes on. I will look into getting O rings tho. Thanks for the help? It never starts hard tho which is weird.

 

x3 but only if you can believe for sure the uvch's were changed.

 

black fuel filter....

 

i just looked up my bill on it and the only replaced the drivers side gasket and harness. I will order the passenger side one tomorrow and put it on. are the injectors hard to pull and mess with on the powerstroke? Ive only messed with the ones on my IH DT466 pulling tractor. im sure they are way harder to replace then them are.

 

If you do a search you should find a few how to write ups or at the top of the page in tech I think one at least it there or someone will throw up a link.Its not rocket science....YOU CAN DO IT!!!

Also,Welcome, I see you are new.

 

Thanks for all the help, and the welcome. I cant wait to see if this fixes it. Its just my farm pickup and it runs good enough for what i use it for but i really would like it to run like a normal powerstroke should. I have a edge chip for it and have had it on and now off for the last coulple months. I put in back on last night to see how it acted today but seems to be more noticiable with the chip when it starts missing and cutting out over half thorttle. I keep checking it for codes but the edge never pick any up.

 

Maybe we just found your problem.

https://www.ford-trucks.com/forums/1...rogrammer.html