gunracer1

ok i find this truck the other day, 248k on it starts and runs great but no power. it feels like it is just getting very little fuel. so we check the pedal travel, it is fine. then we check the turbo and it is fine. then the intercooler and no leaks. then make sure the fuel cut off solinoid is getting full travel, it's fine. check the waste gate and make sure it is not hanging open, it was fine.pumped the lift pump and it bypassed at the banjo fitting so it seems fine.checked the line from the manifold to the afc and its fine. i am starting to run out of ideas on whats wrong.
i checked out more stuff that i am forgetting about. my buddy ended up buying the truck this morning, the guy just went too cheap[96 3500 ex cab 5 speed 4x4 with everything and a texas rust free body 7500.00 and it has never had a goose neck hookup]. it still has the factory converter and muffler on it so it may be clogged.
we are going to put a fresh fuel filter ,set timing to 16, a 4" exhaust on it right away with a bhaf . anyone got any more ideas on what may be the problem?

gunracer1

I could not get it to smoke at all, except a small black cloud at start up. the truck has very little crank case blow by, i have seen way more in good running trucks. mike

MDW

Check fuel pressure

BoldtsWagon

Timing slipped and/or overflow valve?

torquefan

Blow shop air (25psi. max) into the wastegate actuator and make sure it's not leaking boost pressure through a ruptured diaphragm.

MnTom

Sounds to me like the cat is plugged. I had the same problem with mine. No power, egt went through the roof. Drove me up a wall till I found it. I even put a differant turbo on it to no avail. Start it up and go listen to the exhaust. Have someone pick the rpms up while you are listening. If it has any kind of a hiss to it then the exhaust is plugged somewhere.
Tom

dsljunkie

Check the fuel plate position. It may be cocked or slid all the way back (past stock). Slide it forwards about 3/8 of an inch and adjust the afc spring or just cut it in half (if you dont mind the smoke ;D). If the pump hasnt been touched, or possibly been touched "incorrectly" this may be part of whats wrong. You may want to plug the waste gate as well (Worked great on my truck before I went crazy ) Also pullin that cat and muffler off wont hurt a bit.
Good luck
Scott

97Dually

Very easy answer depending on your answer to this question.

Does the RPM gauge indicate you are getting a full deflection up to close to 3000 rps? (2900+) If you cannot get past say 2200 on up I would say you definetly have an Overflow problem. if not, based on your miles I would say your Kitty is plugged.

How about your RPM's?

TJ

gunracer1

i can spin it to 2900 or so, we cut the cat and muffler off it and it is still the same. going to change the fuel filter tonight. mike

dsljunkie

Let us know what happens. Ya know we dont get much excitement in the ol 12valve forums .
Good luck
Scott

RCW

Definitely check your overflow valve. It is located on the inside of the injection pump, next to the head. Sometimes it is necessary to take a die grinder to the head to remove a bit of material to get the overflow valve open. If that is necessary, be sure that the fuel system is closed before you grind, and then clean all the grindings away before removing the valve. If by chance you have a one piece overflow valve, do not even check it, it will be bad and you are lucky to have got this far - just get a new two piece valve from Cummins.

There are a few other things to check if the valve is good. The flexible fuel hose clamps are sometimes replaced with airplane type (the ones with screwdriver adjustors), be sure they are tight. Be sure your fuel hoses are not over three years old, they get pin holes and will leak air under suction. You can pop the drain hose from the return line and look for air in the fuel as the engine is running, it will generally be milky if there is air. Also check your fuel heater for air leaks at the gaskets and the plug where the wire harness connects (put a dab of grease on the connection and replug it to stop air leaks there). Sometimes people do not change the filter screen in the bottom of the heater for years, and it clogs.

dodgeman01

What about the fuel screen on the sode of the engine? I took mine off and it had a layer of crap on it. MPG went up2 and truck ran and smoked a lot more.
DM01

tmiller24

The rollover vent in the top of my tank was plugged and causing me trouble.

gunracer1

well we changed the fuel filter, still no better. then i checked the fuel plate, pulled it out and reground it to a #10 profile. then cycled the arm and checked it location to the plate. it has some power now but not as much as i think it should have. i put the plate in 30k back from stock just to be safe. then we did the timing, it was at 13.5 and we bumped it up to 16. it runs pretty good now, about like a new h.o. i want to put a set of gages on it before i move the plate again. and we have to pull the front cover off it to fix a oil leak. and we will pull the fuel heater apart to see what that looks like. i did crank the star wheel forward, but it still does not smoke. i think we will also put in a new over flow valve. mike

DuallyJeff

How do you check the wastegate to see if it's working properly, or not hanging open?
Thank, Jeff