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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29569
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have an 08 duramax 4wd with a bullydog tuner. I think I

Customer Question

I have an 08 duramax 4wd with a bullydog tuner. I think I ran some bad fuel in my last tank fillup. The truck has been running rough, almost like an old carborated car that you have to have the gas pedal depressed to warm up the engine or it will die. My truck does not die without the foot pedal depressed. It just runs rally rough. I have added some high end injector cleaner, and some other diesel additives just in this last 20 gal. fillup. I was on the highway driving 75 and get an error on my programmer saying "TC LOCKED". Then about 30 minutes later it said pyro defuel and a lot of white smoke was coming out of the tail pipe. I pulled over and let it idle, and there was not anymore white smoke, just black smoke everytime I would try to increase speed. I did not have the cruise control on, as the motor seemed to not like that. I completed my 90 mile trip and fuel economy was under 10mi/gal and not towing anything driving 75mph. I have not taken it into a diesel shop, but had advance
Submitted: 1 year ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 1 year ago.

Hi there, I am Cam. Can I get your first name please?

Can you also post your Vin and tell me if your system has the DPF delete program in it?

Customer: replied 1 year ago.
VIN#1GCHK23627F502685. This is a 2007.5 Chevy Duramax. I do not have the DPF deleted. I have it scheduled to go into the shop next Monday. Thanks Tim
Expert:  GM Tech (Cam) replied 1 year ago.

I am thinking you have a failed injector. That would cause the smoke, it would cause the low economy. Which one will take a scanner to find.

It may also be possible that the injection pump has failed. Some had an issue with a ceramic ball inside the pump failing. If this is the case Tim, then a whole pump, and injectors will be needed. I hope it is only a single injector.