Engine/Transmission (1994 - 1998) 96' poor idel/black smoke no power/stalling

[PetesonM]

My brother called me with an issue on his 96'12valve, the truck is stock (that i can tell) except for the star wheel pushed a little. last week the truck started having a lope issue at idle and would not make any power or stall off idle and lots of black smoke. I checked some basic stuff and found that the waste gate acuator was rusted through and the puck was stuck wide open. had him replace that and throw in a boost guage i had laying arround. the truck idles a little better but it still has no power off idle. I have him getting stuff together for installing guages boost, fuel pressure ,EGT. till then I was hoping to hear some thought from you on what the issue could be? heres the issues...

1-Truck in drive or reverse foot on the brake slight lope at idle about 800 RPM

2-Pulling away from a stop little to no power heavy black smoke

3-Truck in drive or reverse and brake torque it and it will smoke heavy black no power no boost building. and the rpms will not come up even when floored. let off gas ped and it dies.

4- test drive down the road very weak off idle lots of black smoke but once moving the truck seems to function normal#@$%! boost levels arround 18psi.



I know I need to get you guys some fuel pressure readings still but any thoughts at this point would be good.



Thanks.

 

[Hoefler]

Check for a intake blockage. Rat's/bird's nest in the filter box comes to mind.

 

[JKosten]

Also check intake connections.

How much was the starwheel adjusted?

Was the pre-boost (smoke) screw adjusted?

 

[PetesonM]

no blockage I had him check that. star wheel moved ??? 1/4 inch?? no adjustment to anything else. it was driven in this configuration for a couple years, and this started out of the blue. fp guage was put on yesterday and i was told it was arround 16psi. a little low i will try to put the squeze on the return line to check the regulator spring. also found out that the throttle linkage lever was fixed because it broke while investigating other things #@$%! (that would have been good to know). What length should the rod be and could this be the issue? i was told it was doing this before it broke and was replaced but i want to make sure everything is right.

 

[PetesonM]

so this is a follow up and something to think about if your having something like this going on. So the fuel pressure checked out. I contacted the local cummins tech and he said to have the trans checked, it was taken to a local shop and they are saying that it is the trans. he claims they have seen this before and that the trans is junk??? said that the TC is bad when asked about another converter he said the whole trans would need to be replaced? I am by no means a trans expert but why would everything need to be replaced?? sound correct to anybody?? im all for throwing a awsome trans in a truck that needs it, like the other two in sig but ths truck is just used for job bidding and some plowing and light trailor towing, cant justify throwing 3200$ at it. I will be contacting Gorend today and see what Dave the answer man thinks. Any other info would be apreciated thanks!!

 

[Bob4x4]

The torque converter can send debris throughout the trans and quickly do damage. Be sure to have both coolers fluid before reassembly