first time to own, sluggish, help

[mjwells78]

i just bought a '95 gmc with a 6.5 turbo in it and it seems to be a nice truck but it is my first diesel to own even though i've driven big trucks for 10 years. it is kinda sluggish and has little top end power, i never can hear the turbo whine that im used to with other light trucks and was wondering if thats normal or where i should begin the work. it has a little white smoke from the exhaust on starting and if it downshifts on the highway during normal driving to maintain speed then black smoke comes out of the exhaust at what i consider an excessive to moderate level. should i be able to hear the turbo at some point or do i need to install a boost pressure monitor of some sort to see if it is boosting?

[Shikaroka]

Sounds like the typical, NO or LOW boost situation.
Search around here and you will find lots of info on the topic.

A boost gauge, even if temporary, would be a good first step.

[mjwells78]

ok heres more info on my truck.



stalls after running to temp then shutting off for about 5 minutes then hard to start back up.

no sound from turbo anytime that ive found.

first start on cold mornings it will sputter and run rough for a few seconds.

due to it being a farm and road truck, after farm use of not much more than idle most of the time, when i get on the highway it white smokes a little but clears up quickly.

just not much power on low end rpm but gets much worse at over 2000.(think it may be the turbo since i never hear it)

'95 GMC x-cab Z-71 6.5 turbo with automatic trans

obviously i got work to do on the truck but i hope to be able to make it into a really nice truck and any help or advice is greatly appreciated.

[Shikaroka]

With everything stock, you won't hear the turbo much. You would really have to listen for it.

It sounds like you may have some bad/weak injectors. Do you know how many miles are on them?

[mjwells78]

not sure of whats on the injectors but it did put out an error code having to do with the step up pump motor. the truck has 263k miles but i dont know how much is on individual parts. i purchased the truck from a wholesaler so i expected some issues. whats the best thing to do for more turbo boost or will that help because i spoke with a gentleman who has a similar truck and he said his has plenty of power for highway use and low end and he has done nothing aftermarket except for put a hot wire from the ignition to the in tank fuel pump to bypass a relay, or thats the best i could understand from him on the phone.

[Robyn]

Welcome to TDP

You have several issues going on here.
The first thing to check is to make sure you have 26" HG at the vacuum pump and then also at the waste gate solenoid on the LH valve cover.
make sure you have good steady vacuum, if the gauge needle is wobbling all over when hooked directly to the pump its bad news for the pump.
Make sure you have a nice steady vacuum at the wategate actuator too.

The solenoids are notorious for taking a poop.
The PMD can and does cause stalling issues so this very well may be in your future.
The stepper motor code refers to the IP and this is not a simple issue.
I am going to venture here that you may very well be needing to get the IP freshened up.
You need to relocate the PMD (black box on drivers side of IP) to a remote cooler. Long extension cables are available for such things.

I would do the quick stuff first like the vacuum and then take a close look at the IP issue.

If the miles are correct its probably time for an IP.

If you do a freshen on the IP install a fresh set of injector nozzles too.

Hope this helps.
Robyn

[mjwells78]

gives me lots of places to begin work, thanks for your help, not good with all the abbreviations though, first diesel remember, but im lookin it all up...lol