I was noticing about a week ago when my 99 F350 would get to about 40 mph , I would get vibrations like a wheel was falling off or something but couldnt find anything... but last night around midnight on I-70 , my truck missed a beat , then another , then it started vibrating very badly , shuddering and would barely pull itself.... All I could do was mash it to the floor and it would shake violently but would hold 35-40 mph like that . I had a dead phone and dint want to freeze to death (-11 ) so I kept going as long as I had to to get to a town... (about 15 miles) ... when this happened I noticed the EGT gauge that always cruises at 800 degrees was stuck down around 200 degrees... so I pulled into a truck stop and as it idled it was banging loudly .. after getting someone to follow me , I decide to try and get home , I restarted the truck and noticed I had 400 degrees egt and it had a touch more power , then I had 800 again and it started to clear up , then it was fine for the rest of the 50 miles to home.. ??? Runs fine today , but dont want to go through that again ... any ideas .??? Pulled 2 codes today P1280 and P 0475 , cleared them , restarted the truck and P0475 shows up again but it is still running fine .. Help ...

 

at -11 could be fuel jelling, do you run any additive in it? like the white bottle of powerservice.

 

I had already driven about 125 miles when this issue started, thats why I didnt think it was a fuel problem??it was 2 degrees actual and -11 with windchill.. Never had any gel problems in the last 7 years and 200+ thousand miles as the northern fuel suppliers usually keep the fuel treated, but It could happen..... What do you think the EGT dropped to 200 degrees for for those 15 miles while it was shuddering with no power?? It seems like it would be really rich on fuel to cause that ????

 

It certainly sounds like fuel starvation to me. Been there, did that, hated it.

 

If it not getting enough fuel to burn then the egt gauge won't read high

 

Oh , I never thought of that , I was thinking rich on fuel would drop the temp.. I didnt know lean would as well ... I just had a new fuel filter (leaking a bit) , and a new CPS put on 2 weeks ago at Shied diesel when it died on me and had to have it towed in .... They said fuel had some algae in it ? and gave me a fuel treatment to put in it ....now this .. Ugggghh


come to think of it , the fuel gauge has been acting up for about 3 weeks now , yesterday when this happened I had a good reading of 1/2 tank, after I started it back up at the truck stop it showed full , for about 30 miles then went back to just under 1/2 .... any connection ???

 

If you have algae in your tank and it's being treated, after you've completed at least a full tank...you probably ought to open up your fuel bowl and remove the fuel heater element to see the bottom of the bowl. Make sure it's not full of sediment, algae, whatever. That can block fuel flow as well. Clean the bowl out really well and put everything back in.

 

What he said, when you treat the fuel for algae you need to do a few filter changes. As the nasty stuff breaks up it clogs your filter.

 

[QUOTE=bigb56;13840875]What he said, when you treat the fuel for algae you need to do a few filter changes. As the nasty stuff breaks up it clogs your filter.[/QUOTE

Ok I'll have a look inside the filter assembly tomorrow,,,,

 

Sounds like a loose UVCH to me, but you're not getting the tell-tale 1316 code for that.

The P0475 code = Exhaust Pressure Control Valve Malfunction.

Is your EBPV gutted? If not, is it possible it's getting stuck closed?

Stewart

 

no , nothing has been modified from original ..... i did however replace the tube that goes from the EBPV sensor to the exhaust manifold a couple years back , as it had a hole rusted in it ...

 

That was what I thought when it happened to me. After ohming out the injectors at the 42-pin connector countless times, and spending $400 at a dealership without getting it fixed, I finally found a small inline fuel screen the PO apparently installed. It was plugged up, causing the fuel pump to suck air at the suction side o-ring. I finally figured it out when I pulled the fuel filter cap off, and the bowl was nearly empty. I proceeded to gut the little screen-filter-thingy and went on my way without further issues.

My EBPV has never closed, so I don't know what it would feel like but my gut tells me it wouldn't cause symptoms of a misfire. Also it should cause the exhaust temp to spike, rather than fall, especially at WOT.

All things considered, I'm still leaning toward fuel starvation on this one.

 

a truck I work on had a similar symptom, they could go for hundreds of miles and never miss a beat and than would randomly loose power. they would have someone come get the horse trailer and have the truck towed to my shop, only to have it start and run perfectly. after several of these and many hours of troubleshooting I told her that I was going to drop the tank and check the fuel pickup, she suddenly remembered that she had it at another shop and they had dropped the tank to clean it. I went ahead and pulled the tank and found a red grease rag in the tank laying flat on the bottom. apparently it would randomly work it's way under the fuel pickup and starve the pump. when the roll back tow truck would pick up the truck the rag would go back to the back of the tank and the problem was gone until next time.

 

on my sister's excursion it would randomly loose power and shutter, turn it off and re start it and it would run fine for a while. it turned out to be a uvc harness unplugged under the valve cover but not all the way unplugged.