OK somebody tell me whats wrong with it?!?!?!?!?!?

[94f450sd]

ive been chasing this for almost 6 years and ive about had it.this all started after the first emission test.fuel mileage sux.it has a skip i cant find.if it sits for more than a day or its real cold it has valve or 2 sticking open.EGTs through the roof 1 day and cool the next.ive done 3 IPs and 2 sets of injectors.

1 day its nutless and cant get out of its own way.the next it will run like a ***** ape.yesterday with a mazda pickup on the back i let out of it in 5th to get of the exit and a huge very thick cloud of black came out of it.it was worse than my PSDs smoke .couldnt get out of its own way.1050* at 65MPH on flat highway.

today it had more balls than brains.running down the highway with a jeep on the deck at 75MPH flat highway at 800*.now this was the exact same stretch of highway i was on with it at 1050* yesterday.


when it runs out of fuel you better hang on cuz it grows some nuts takes off like a jet.switch to the other tank and its back to being nutless.


boost seems ok.it runs around 2PSI on the highway and itll go to about 6PSI.i havent adjusted the wastegate or pump yet cuz my EGTs are still through the roof even with the ATS junk exhuast on it.


any ideas???????i hope somebody does cuz ive run out them and patience.im about ready to pop the PSD and stuff out of my pickup and stuffing it in this thing.

 

[Diesel JD]

Maybe you need to do the PSD swap or get another IDI motor. This one might be a **** for whatever reason. There are some IDIs and PSD both that are built like that from day 1. It sux if you got one.

 

[yARIC008]

I'd suggest a compression test. That may clue you in on maybe exactly whats going on. You say it has sticky valves... that can't be good for anything. The valves are known to bounce around in these engines because of the lack of lubrication from the valve stem seals...

 

[suv7734]

A couple of thoughts... Have you checked the pressure and volume at the schraeder valve on the filter head. The feeling like a locomotive ran into the back of you is common when one tank is about to run out of fuel. If the lift pump is weak it can feel similar at certain times. Another thing to check is the rubber hose from the frame/tank line to the lift pump. They can get a small kink in them and while not noticable at lower speeds under load/higher speeds it can cause a problem.
Just some thoughts.

 

[geonc]

Rich, have you checked the return fuel line?

At the rear of the eng where rubber meets steel.

Just another thought

 

[subway]

sounds fuel related, had something similer happen with my old bronco. turned out the be the mechanical fuel pump. bugged the hell out of me because it wouldent do it on a regular basis. heck the previous owner chased the problem for about a year and gave up.

i know what you mean with the truck jumping when it is low on fuel, wish it was that peppy all the time.

 

[94f450sd]

Rich, have you checked the return fuel line?

At the rear of the eng where rubber meets steel.

Just another thought

yup

sounds fuel related, had something similer happen with my old bronco. turned out the be the mechanical fuel pump. bugged the hell out of me because it wouldent do it on a regular basis. heck the previous owner chased the problem for about a year and gave up.

i know what you mean with the truck jumping when it is low on fuel, wish it was that peppy all the time.

replaced the lift pump twice as well

 

[Agnem]

Sounds like there is something intermittent going on, and some instrumentation may help. I'd put a fuel presure gauge in on the line from the filter head to the IP. I'd also (and I know this sounds crazy, but it would only be temporary) run a clear line from the filter head to the injector returns, that loops through the cab somewhere so that you can look for air in it. The smoke and surging can't be valve related, but the miss could. You may have multiple problems, that are unrelated, so patience and smarts will be needed to solve them. The change in EGT's and performance definitely sounds like it is timing related, but you say you've changed IP's with no change in symptom, which is why we are all leaning towards a fuel presure problem, since presure affects timing.

 

[94f450sd]

i know i have a couple leaks on the return side.i need orings on 2 injectors and filter head.but it runs like this even when there are no leaks.it needs an IP as well but it will still run like this with a new IP.

 

[wwwabbit]

Have you checked your tank switcher valve? If it is clogged/not switching the return lines correctly it would build up preasure in the return and change the timing.

 

[94f450sd]

ive been through the fuel system from one end to the other.ive replaced most of it.

 

[Agnem]

I'd still fix what you know is broken first. Too much assumption when troubleshooting is a sure way to go broke or insane, and right now it seems to me there is a lot of assuming going on. You need to be SURE by whatever method is necessary.

 

[Diezel_Cowboy]

i know i have a couple leaks on the return side.i need orings on 2 injectors and filter head.but it runs like this even when there are no leaks.it needs an IP as well but it will still run like this with a new IP.

Nothing like answering your own question!

 

[hesutton]

I agree with what has been said above. Certainly sounds like a fuel issue. If you need an IP and there are leaks at the return caps, then that's where I'd start for sure. A dead or dieing IP will do all kinds of weird crap, inconsistant timing, fuel delivery, or both would cause symptoms like you are having.

Heath

 

[94f450sd]

Nothing like answering your own question!

no answer to my problem there.you mustve misread it or something.doesnt matter what i fix or replace this thing will still run the same.always has.