99 6.5L Hard Start, Black Smoke, no power

[Rh31379]

Hello All,
I am new to the forum but have been monitoring a previous post from a friend. He's on vacation this week so I do not have access to the account. You guys saved us on this thread: http://www.thetruckstop.us/forum/threads/hard-cold-start-on-1999-6-5-chevy-p0251-code.47206/

Truck has been running pretty good, no starting problems but lacking power it seemed through a . Now back to hard starting and a check engine light is back. I get P0251, P0236, P0380, P1656.

I think the glow plug controller is bad. I get a WTS light but do no here the click and no power to the glow plugs. That'll cause my hard cold starts again which makes sense because I am not seeing any air in the clear line on the return and once it is running it's not acting like it had before. It seems like I have some extra soot on the air cleaner so I may have an exhaust leak keeping the turbo from spinning but I haven't had a second person to help so I could look.

I didn't get a chance to check the vaccum because it started to rain but the vaccum pump was replaced less then a year ago.

Can anyone offer any other insite into these codes? I do no here the turbo spooling at all and definetly seem like the truck is lacking acceleration.

Thanks for any suggestions you guys offer.

 

[ak diesel driver]

check the air filter?

 

[Rh31379]

I did. It's not to dirty. Only a couple months old

 

[1994ch]

Sounds like you listed off most of the first things I would check.......... get the glow plugs running and make sure that you have vacuum to the turbo waste gate controller. Unless you want to put a spring waste gate controller on it.......

 

[snarl95]

Try to move the waste gate rod while the truck is idling. It shouldn't move.

 

[WarWagon]

Check the grounds!!!

The glow plug controller is just a dumb relay on your year. Check you have 12v on one terminal with the key off. Friend turns key on and you have a click and 12v on the other terminal. Cold engine.

I suggest you have a vacuum problem including the vacuum control valve (common failure) for the WG controller on the turbo. Vac pump working and all lines in good shape?

 

[Rh31379]

I did have 12v to one side of controller and nothing on the other. I did not get to look closer yet to make sure I'm getting 12v from the signal wire to throw the relay.

 

[WarWagon]

12v signal and GROUND to the controller. Sounds like you have a handle on the glows otherwise.

 

[Rh31379]

Well before I replaced the controller I decided to check for signal power to the controller. I had none. Found a blown fuse in the fuse block. Replaced the fuse and turned the key on and saw a spark at back of the valve cover. I found 2 broken green wires that seem to have been broken for a while based on there color. But also found one of the wires for the turbo vacuum switch had very slight wear and must of been grounding out and blew the fuse and also killed the turbo. Fixed the wires, tied things up and the truck started right up/
Went for a few mile ride and everything seemed good then all of a sudden the truck lost all power again and was just pushing out black smoke. I pulled over and pulled the air cleaner and it was filthy (only a few months old) my guess is when the vacuum actuator was not working the exhaust was pushing out the mating surfaces between the turbo and the manifold and the manifold and the exhaust pipe. Used a blow gun in the tail pipe and soapy water to figure it out. The exhaust pipe to manifold surface shows signs of age. Anyone make a gasket to help that? We changed the gasket under the turbo, sealed the air cleaner up (clips had been broken) and things seemed much better again.
Gotta 40 min ride this morning so we'll see how things go.

Thanks

 

[WarWagon]

You mean the crossover to passenger side manifold (Should be a doughnut gasket there) or turbo to exhaust pipe (Just a v band clamp)?