I have a 97 1/2 ton chevy pickup 6.es model with an egr system. I had the vo-tech school rebuild the motor with new pistons, rings, injectors, had the injector pump rebuilt and calibrated, new pmd, new primary pump, new rods,mains,cam, turn the crank, bore .25 etc.The heads were completely rebuilt, I took the truck to a chevy dealer to have it "learn timed" and it still smokes like a tire fire. It has no power and if I put any pressure on the accelerator it lays smoke so bad the vehicle behind me dissapears. The school tells me that is just the way the truck is, and chevy said they don't have any idea. We also have a 93 one ton with an F model 6.5 that was just rebuilt by the same school and it is doing great with no smoke. does ANYBODY have any ideas? One more thing the turbo was spec'd out also. Help!

Are you getting a SES light? if you don't have a scanner some auto parts store will check for codes for free. or somethings to check 1st get a vac gauge and you should have ~20" or more of vacuum at the vac pump and ~15 at the Wastegate Solenoid. If all of that is okay most likey it's the wastegate solenoid. I've replace 3 on the 4th now. Also Welcome and please update your sig per the welcome new forum member.

Thanks For The Ideas, When I Cant Figure Out How To Do That I Will. Really Appreciate The Help

Is the truck hard to start?

Sounds like the symptoms of a wastegate solenoid failure. Do you have a boost gauge to see what your turbo is doing. Might be something to check.

Thanks for all the help, no the truck isn't hard to start and it doesn't smoke until you apply pressure to the accelerator then it belches smoke and continuest to smoke until you let up on the pedal. I don't have a vac guage or a manual but it sounds like I better get one.

Since this truck has an EGR and possibly a MAF, The wg solenoid isn't the only thing that controls boost. Check for EGR function by pulling the vac line off of it at idle and putting your finger over it. When you feel the vac and pull your finger off the EGR should click closed. On the other end of the EGR vac line is the baro. It must get ~20" Hg of vac or boost isn't commanded by the ECM.

If you have vac to the EGR and turbo, put a screw in the line to the EGR to block it off. Disabling the EGR is better than getting it to work right.

Your TDC Offset is wrong, take a look at where the pump is, I'd almost be willing to bet that its laid over to the Driver's side too far, retard it to get the ESO about perpindicular and see what happens.

qm, I did the screw-in-the-line procedure on mine and now it runs great but mine is a 95'. Don't the computers in the newer ones (97') throw a code if you do that?

They have the engine timing chain/pump out of time.
Easy for non experience "mechanics " to do.
Have the Vo-tech guys open her back up for exploratory examination.

Okay, I took the vac line off the egr and blocked it. No change, I checked the vac at the waste gate solenoid, 15 pounds at idle. When hooked up the solenoid arm appears to retract about an inch with throttle. but I don't hear any boost. Still Getting LOTs of smoke. I really feel sorry for anyone behind me if I have to speed up. Oh by the way, I had it learned timed at the local chevy dealer and they swear it's right. I think I better have the vo tech guys open it up to have the timing chain looked? Any thing else I can do before that?

try some bailing wire around the WG actuator to make sure it keeps the gate closed and see if that helps... just be easy on the throttle, don't want to overboost the engine...

get some HD intake manifold gaskets with the steel block plates where the egr passages go and install them... that will make sure the EGR system is disabled..

A stiff spring would be better.

I will try wiring the waste gate closed as you suggested and I will be easy on the throttle. I am not sure how to block off the connection between the intake and the exhaust on the egr thoug. Is there somewhere I can see a diagram of what it looks like before I open it up so I can be sure I have what it takes before I do it? This is my transportation and if I can't drive it I can't get parts.

to block the egr, you could make a test gasket out of some copper or aluminum [±0.050" would do for testing], pull your egr valve off, use that gasket as a template to make your new gasket, but don't put any holes in the new one other than for the screw holes, the bolt it all back together with the "test" gasket... if that fixes your problem... well, you could leave it there, or make better gasket or steel blanking plate and use a new OEM gasket. one better would be removing the intake manifold and replacing the intake gaskets with the HD gaskets which i am 99% sure have a piece of stainless steel in the hole where the exhaust gasses should flow from the heads into the manifold to the egr valve... [or do that and swap in a HD manifold???]

man, i miss my 6.5td tahoe.. it was underpowered, but a blast to drive