1996 6.5TD Black Smoke/Rough Running

[Ed2000]

Need some help from anyone in North Atlanta, Ga. I own a 1996 Suburban,6.5 TD, 4X4, 220+K miles, and the engine is running very rough on start-up. The engine starts-up with NO problem, but blows lots of black smoke and run erratic, as if the fuel peddle has a mind of its own. Its almost impossible to maintain a constant speed on the fuel accelerator, for the truck wants to slow down, or take off. When it accelerates, it blow lots of black smoke!

Question, is this a fuel injection pump issue, or may I have an injector stuck? I do not suspect the FSD, for I have switched them already and nothing. Second, I hooked-up an OBD2 code reader, and NO code being shown.

Last, is there any GM dealer in north Atlanta, GA, or anyone who can diagnose my truck for me? Although, I suspect I will not be able to drive the vehicle to them, for it really runs bad. Also, what is the best company to buy a complete rebuild 5.6 from? I just want to have options.

Any help would be most appreciated. My truck has been down for 6 months now. If I can not fix it very soon, the wife told me to sell it.

Thanks in advance for any responses.

All the best -

Ed
Murphy, NC
figueroa@ellijay.com
706-455-3219 Cell
888-231-2151 Pager

[MrEdd]

Be careful with dealers. Most Chevy dealers in the Charlotte area around here look at my 6.5 like its a Ford.

[Ed2000]

I think I will just sell it, if someone offers me 6K for as is.

Thanks

Ed

[IronChevy]

I'm having the same problem with my 1997 2500 with 270k, no codes either. I had to bite the bullet, I've just ordered a new injection pump. Hopeing to install it in the next week or so. I'll let you know if I fixes it. I've spoken to a bunch of people about it, it all seems to point to the IP. It sounds like it will be fun to install but I figured if it doesn't fix it, at 270k and new IP wont be a bad investment. Good luck.

[autocrosser]

You might try checking your cat converter to see if it's clogged. It happens on them. I have seen a number of them cause a lot of black smoke and power loss etc.

If you take it loose at the downpipe end you can look in the converter and see if there is a soot build up. Also drive it with the converter loose. That will really tell you if it;s clogged.

[beast]

sounds to me like a problem with the waste gate.

[Kennedy]

Erratic fuel delivery and uncontrollable engine speed is more than likely a bad pump. Many have tried to replace peripherals (including APP module etc) without success. A new pump and CLEAN well additized fuel is waht I would prescribe.

[Likearock]

I'm having the same problem with my 1997 2500 with 270k, no codes either. I had to bite the bullet, I've just ordered a new injection pump. Hopeing to install it in the next week or so. I'll let you know if I fixes it. I've spoken to a bunch of people about it, it all seems to point to the IP. It sounds like it will be fun to install but I figured if it doesn't fix it, at 270k and new IP wont be a bad investment. Good luck.

What was your final solution to your fix? Mine is exactly the same.