Engine/Transmission (1994 - 1998) wastegate repair and test help...

[Hootguy]

Hi all,,

The truck in question is a 96 3500 dually 4X4 automatic,

i have suddenly lost power under boost condition,,if i drive in low boost,,,say 10 and under and accelarate slowly it goes fine. . same if i acclerate in 1'st and 2 gear... then in drive it starts to loose accellaration,,in OD it hardly accelarates at all,,very slowly,,,the fuel filter is only about 5 tanks old,,,but i'll change it just to be sure it's not fuel related,,,the turbo is original to the truck,,and i believe the wastegate may be seized,,,i use the truck daily so i would have thought that would be enough to keep it from seizing,,,but i would like to look at all the possibilities,,,so if anyone can give me some tips on how to test,,,remove,,or free up the waste gate i would sure appreciate it... if someone can tell me if i can do this without removing the turbo itself that would be great. . also,,i remember reading years ago about a wastegate repair kit that was available,,a few members on here had used them with succes... thanks for any help.

 

[fox]

Can you move the wastegate arm? It could only be stuck open to cause this issue.

 

[MChrist]

I don't know if this will help, but on my '06 the waste gate has gotten stuck closed twice from not using that skinny pedal on the right enough. I disconnected the air hose going to the actuator and blew a quick blast of air with my air hose. I watched it move, then it was OK. If yours is stuck open, that won't be any help, though.
I would think that if your gate was stuck open, and if you floored it, you could still see max boost at high load or RPM. If not, you may have a different problem.

 

[Hootguy]

Hi thanks for the replies... can the arm be moved by hand??,,does it need to be disconnected?? if so,,how do you disconnect it while in the truck??

I kinda feel it might stuck partially open since i can get about 15 lbs of boost in the 1'st and second. . i'm really hopping to get this resolved as this is my only vehicule,,,

 

[cerberusiam]

If your making any boost the WG is not stuck open. Can you get 15 psi all the time or is it lower in Drive and OD?

 

[Bob4x4]

Check your fuel pressure first,if it is ok check for boost leaks

 

[Hootguy]

Hi guys,,,,it makes up to 15 in 1 and 2,,,drive 10 max,,if i floor it,,,i get a lot of blue smoke but no power,,feels like a partialy clogged filter,,but why would it be good in the first 2 gears,,,???,,,,,the filter is onyl about 2 months old,,,i do run bio diesel that i make,,but my filters usually last a year,,,,,,so if i make boost at all,,my waste gate should be working???. . is there anything in the AFC that could be messed up??? i allready check the supply tube,,i replaced the plastic one with a metal one a long time ago,,got tired of replacing it after it metled when the grid heaters would stick on,,LOL... i also instaled a switch to keep the grid heaters from sticking on,,,now they only go on when i switch them on...

I hope i get this fueling issue sorted out soon,,

Thanks for all your help.

 

[cerberusiam]

Hi guys,,,,it makes up to 15 in 1 and 2,,,drive 10 max,,if i floor it,,,i get a lot of blue smoke but no power,,feels like a partialy clogged filter,,but why would it be good in the first 2 gears.

Better mechanical advantage and it will spin up even though the engine is off.

Change filter first and see if that helps. If the filter and fuel supply is all good, check your timing. Really sounds like it has slipped retarded. Thats generally the source of blue smoke when everything else is good.

 

[MLee]

Not wanting to hijack this thread but--

Another question to through out there on the waste gate, Would the Exhaust brake cause more sooting in the waste gate area? I know he has a auto trans.

My waste gate is blocked. But depending on rpm my boast is 15-20. Seems to pull better @ 12-15

thanks for your replies

 

[MLee]

Have you check your fuel plate? maybe its sliped back some. How about the afc boost line connection? tight? hose connections?

 

[Hootguy]

Hi guys,,,i have taken the truck for a run this morning again,,after beating on it as best i could yesterday,,,i did drain some fuel from the filter while the truck was running,,and let it settle,,there was some debris in the bottom but not that bad,,,during this morning's run,,i did see i can get pretty decent accel and boost up to 24 in drive,,but then in OD,,the fuel seems to starve and draw the boost down to 10 and worse,,,i guess i'll change the filter and eliminate that possibility,,i hate changing out $25. 00 filters for nothing,,

 

[Bob4x4]

If you only have a few tanks of fuel through that filter and you have debris in the filter housing already I would clean the tank.
Also I see alternative fuels in your signature

 

[Hootguy]

well. . ichanged the fuel filter,,,and no change,,i still loose boost and power in OD,,,if i baby it under 10 lbs,,it run go down the road ok,,but if i step on it,,nothing,,it falls flat on it;s face,,at this point,,i'm not sure what to do anymore,,and on the week end no less,,,i'll try and find things to check again tomorow,,the tank was cleaned about 2 months ago,,along with brand new OEM lines,,,if anyone has any idea what else i can check,,please let me know,,

thanks for all the help

 

[cerberusiam]

Timing. Sounds like the slipped on the shaft. Blue\white smoke is uncombusted fuel from very late timing injection. Either the pump, timing, or fuel supply causing it. Since the P7100's had a habit of doing that very thing, start there.

 

[Hootguy]

is it possible for the wastegate to let go under boost,,,,,and is there a way to keep it shut so i can test it with full boost capabilities,,,i heard of members wire the wastegate sgut somehow,,,i could at least eliminate the wastegate diaphram from the problems.

 

[Bob4x4]

Quit guessing and start testing.....

 

[Hootguy]

i'm going to do just that tomorow,,,i'll plug the boost elbow with a pipe plug and see if that helps,,then i'll take the AFC appart and check the diaphram,,and see if the fuel plate is loose,,,then i'll check back onhere and hopefully get more ideas,,,if not,,i'll drop off the truck at a diesel place and go shopping for another truck,,

 

[S.Morris]

Is there more to this story? Why was the tank and lines just cleaned 2 months ago? You need to get some test guages set up to monitor fuel pressure... ... . seems like that is at issue. Maybe a partial blockage of small screen right at pump inlet.



At any rate... ... like BOB says... ...

 

[MLee]

Have you pinched off the return fuel line, a quick check on the overflow valve.

Maybe you got a bad load of fuel after the tank had been cleaned and there is gunk plugging the pick up filter.

 

[Hootguy]

thanks for the help guys,,i'm off to try and test stuff,,a little background on the truck,,,i make my own biodiesel,,,these P pumps will tolerate just about anything,,,and before someone starts with the "i'll damage my truck and cause engine damage"... . this truck has had all kinds of fuel for the last 500,000 km's,,from biodiesel,,to canola oil/diesel or jet fuel mixes,,,always ran great,,and i always changed filter regularly,,,the reason for the tank remove and clean was because i do it every few years as preventive maintenance,,,i also had a friend give me brand new dodge OEM lines,,,so why not put them in,,mine were pretty rusty,,,i ALSO,,removed the whole pre-screen heater assembly that always seems to give older truck trouble,,,and the big truck running the same motor combo as us dont even have that assembly,,,instead they run a simple inline filter before the lift pump,,,now here's where i MAY have gone wrong,,,i plumber the supply line directly to the lift pump using JIC fittings... . i was SUPPOSED to install that little inline filter the next day,,,BUT,,,i didnt of course,,so now i'm wondering if i might have scored the inside of the lift pump preventing it from giving me full pressure when i need it in the high boost high load time,,,I KNOW,,IKNOW,,,LOL. . i'm shopping around to get a fuel presuure gauge today,,,i want a permanent install in the cab if anyone has a GOOD reliable suggestion,,i would like to have a pre and post type set up so i can monitor fuel filter condition,,,so if anyone knows of a good set up,,please let me know,,i hear a lot of failures with FP gauges,,would a good old mechanical set up work better???,,,i know most dont like diesel in the cab,,but bio isnt that bad... i'll try and see if i can make a temporay pressure set up today with my transmission line pressure test setup and line...

Thanks again... . hopefully i can fix this soon,,,also,,the overflow valve was changed 1 month ago with one from Larry B's. .