I have a 94 3500 manual, with straight pipe.
The other night I was hauling to a rodeo when there was a loud pop sound, like I had a tire blow out. I loss power and there was a rattling sound in the exhaust system. The engine idles fine but is slow taking off, like no power. When you get up to 2000 rpms it starts blowing white smoke, and acts like it is cutting out. I have changed fuel filter, and checked rubber boots on intercooler and turbo. Also checked the turbo, and it spinns free with very little play in it.

Does anyone have any ideas as what to check for?

 

if you have a intercooler , I would pressurize the whole system and check for leaks.

 

Check all of the rubber elbows that connect the turbo to the intercooler to the intake manifold. Sounds like one of them is loose or leaking or ripped. Same thing happened to me. Tightened the clamps and all was good again.

 

all the hoses may be alright , but pressurizing the system will be able to see if the intercooler itself may have blown a weld apart.

 

The bottom passenger side boot on '94-'96 is prone to getting cut by a sharp edge of the fender. It looks like there is room but when the boot puffs out at high boost it rubs. This can make a cut and leak that is hard to see when there is no pressure to expand the boot.
On most every earlier 2nd gen I work on I check this spot and bend the sharp edge back from the boot.

 

same thing is happening to me 97 dually at aprox.the same rpm it stars to cut out and will die unless you back off completely then its ok unless you go further into the throttle

 

The white smoke sounds to me like slipped timing. Black smoke would be a turbo boot from my experience.

 

What are your EGT's doing? A boost leak would result in low power with high EGT.

My truck did something similar a few weeks back, but without the white smoke. Check your fuel pressure.....

 

egt were norm. but I noticed since this prob occurred my pyro has stopped working.I havent owned this dually too long .but Ihavent even hauled a load worth mentioning sinceIve had itand the egts have never even gotten warm never mind hot

 

Yesterday I had a buudy follow me. He said it is black smoke coming out the exhaust.

How do I go about doing a pressure test on the intercooler system?

Also notice that the engine seems to ideal faster that it use to, and that the turbo use to wined down when you would turn it off. Now as soon as you kill the engine you do not here the turbo winding down.

As far as boost or temps, I do not have any gauges on the truck to check.

 

First off....you need some gauges.

Sound like a boost leak to me.......

 

Chech the turbo and see if it still spins. You may have a blown turbo.