hey guys Im back again looking for some help with my 7.3. it has 170000 miles on it totally stock, just before xmas started to act up.... it has following symptoms..... on cold start up will stumble and hunt for rpm starts no smoke then after bout 3 to 4 min starts to throw white smoke when warmed up to temp gauge move smoke goes away and rpm smooths out but still seems like it is only running on 6 or 7 holes. at times when pulling away from stop pedal moves and truck barley responds and then catches and goes like hell. at highway speed it will cut in and out at times but never quit....not all the time especillay if im on it aver 2200 for any length of time..... then it will run really loud like the exaust is exiting right under my feet and have huge lack of power.... then if i go down hill and get off pedal for any length of time when \i get back on it it will be nice and quiet and pull like crazy.....which it should cause ive replace just about everything on it to try and fix this. so far ive done the following so you guys that have the experience will know where Im at with this thing.... 2 new batteries....new alternator....COMPLETE fuel system from tank to rails with x-over....new ICP.....3 new cps (two grey one black)....new injector #8.....all injector o-rings......compression test all between 375 and 400....new UHVC gaskets and harnesses.....new IDM (that one hurt$$$) all wiring was ohmed and checked out excellent .......ccv mod (intercooler was full of crap and cleaned it out)....new throttle pedal assembly...... taken it to 3 dealerships so far and each one has taken my money done scan tests and told me they dont know what the problem is.....only codes it has thrown is once high side open on #2 bank and then again later it was both banks high side open. never ever a SEL light ever... Im out of ideas of what this is.....need some help if its possible....... oh ya I dont have an AE and now just about out of money but did get dealer**** to do a IPR-ICP run for me and the numbers looked good topped out at 2875 at 42% but then again the truck was running well at the time it went to that dealership.... thats the problem.....this comes and goes thanks in advance for any help

 

Well you changed out alot of parts only to still have the problem. What yr is the truck? Did you check all your wiring harness for chafing. Look real close at your pigtail for your UVCH. Too me it sounds electrical, wiring chafing somewhere and causing your intermedite problem. What was the code number it threw? Do you have any boost leaks?

 

both pigtails were replaced and soldered on, forgot to mention that both up pipes were replaced aswell, I did take a real close look at the large connector that is said to be prone to chafing but it looked fine no rubbing on it....i didnt get a print out of the codes it threw but I believe it was 1293 and 4 I think..it said high side open bank 1 and high side open bank 2......curious~~~ just noticed tonight for the first time that my fuel cross over lines I got from Clay pulse hard when the truck is running,,,,that doesnt seem right to me.....could this be compression getting into fuel rail? they have a definate hard pulse that speeds up as rpm increases.

 

X 2.

You might have GP or GPR issues, but that's just a startup thing. Plugging in might help this one, give it a whirl.

Loud, eh? New ups, but old manifolds? The driver-side manifolds notoriously leak near the firewall (mine did). Is soot lurking around your engine? When you experience your power loss, is anything happening at the tailpipe? When were the ups replaced? Was anything done to your truck at all - just before Christmas?

 

Was anything done to the throttle(petal) position sensor, cleaned or checked that ? That sucks to do all that & still have the problem. Edit - Sorry - just re-read op & saw that was replaced

 

truck is an 2001, gpr was replaced in october and glow plugs were checked and ohmed when o-rings were done on injectors....... no soot on engine....only soot was on the up pipes so they got replaced.....when the loss of power and or ruff running happens at idle you can hear it missing in the tail pipe...... thanks for the input so far you guys

 

Do you have a chip or tuner installed? If so take it back to stock. Have you ever pulled your PCM out or disconnected it? If you have you might have a recessed/bent/loose pin. Did you check your 42 pin connector and harness real good for chafing.

 

no turner at all everything is stock, checked harness really well no chafing, have not disconected the pcm, that is one of the few things that has not been replaced yet.........was still wondering about the fuel rail crossover from riff-raff that I installed..... its is pulsing hard I just noticed it yestersday so I ran it up today looking for bubbles in the fuel bowl or dirty fuel from possible combustion getting into fuel rail and everything looked perfect in the fuel bowl.

 

Put a fuel pressure gauge on it and see what it reads, at idle and while driving, also it might be a hole in the fuel pick up line in the tank, or clogged, you would have to drop the tank to check, also the line you said is jumping, is it going from head to head under the turbo, across the valley, if so that's a oil line, the fuel line would be at the end of the heads. Also check and make sure the warm up butterfly is not sticking shut. Just trying to throw some things out there that might help, hang in there, these guys and gal's on here are the best.

 

Do what jwhitetail said, put a gauge on ur fuel bowl to see what kind of fuel press ur getting. The FRx should not be pulsing like that.

 

thanks for the help..... the tank should not be an issue I just did the tank mods and put in new pump with pre filter as tank stuff was gutted and new pick up put in..... the lines that are pulsing is the FRX line that I got from Riffraff.... the line from the drivers side head seems to be hitting harder than the one from the passenger side which would lead me to beleive that the sourse of the hammering is coming from the driver side head. Im gonna call Clay in the morning and bounce it off of him to see what he thinks. Ill put a pressure gauge on tomorrow will let ya guys know what I find.... once again thanks alot you guys

 

If your FRx drivers side line pulses alot, make sure its not rubbing on the turbo. Give Clay a call and bounce it off him. Maybe something is wrong with the regulator. A fuel gauge will tell you.

 

ya thanks for brining up the rubbing on the turbo as Im sure it will be doing that Ill get some armour guard tomorrow when I pick up the pressure gauge....thanks..

 

Just checking to see if you found the problem or got it fixed yet. Did you talk to Clay?

 

Darryl, the problem at first start up could be the AIH(air intake heater), it comes on for the first 2 minutes on start up. It will stay on if you don't touch the go pedal, if you touch the pedal it turns off the AIH. The AIH is run off of the other relay next to the GP relay. HTH's Lee