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REMF
05-05-2009, 08:38
My Son’s 93, GMC 6.5 just had the tranny re-built (you all know who paid the bill :mad:). Was running fine engine wise when we took it in, but now it's throwing a lot of white smoke on normal acceleration and idle, and it has a very rough idle. I have read other posts on white smoke but have found nothing on a 93. There are no vacuum lines that I can see. It seems to have lost some power as well. The turbo seems to be spinning fine and ramps up on acceleration.

Trying to keep it out of the shop as I don’t want to pay another large shop bill.

Any suggestions would be great.
DaveBr
05-05-2009, 19:27
Check to see if your lift pump is working. It is on the frame under the drivers door. Looks like a fuel filter with 2 wires coming out of it.
Robyn
05-06-2009, 07:08
Check the fuel filter.
More issues have been traced to fouled filters than I care to think about.

Could have a bad injector.

As mentioned, lift pump

Robyn
REMF
05-06-2009, 08:25
Thanks guy's.

Have replaced the fuel filter same outcome, just looking for a lift pump now.
REMF
05-06-2009, 14:07
Lift pump changed, idle seemed to smooth out a bit, but still white smoke on idle and black smoke when you hit the accelerator. Added some conditioner injector cleaner.

Do I need to have him take it out on the hwy to blow any residual soot out of her?

Thanks
DaveBr
05-06-2009, 17:25
If you drive it and stop at a light are you still getting white smoke or is it just on startup?
REMF
05-06-2009, 17:38
If you drive it and stop at a light are you still getting white smoke or is it just on startup?

Yep. White while idling and black on hard acceleration (more smoke than normal it seems).
REMF
05-11-2009, 08:35
Any other suggestions/ideas before she goes to the shop?
DaveBr
05-11-2009, 17:00
It's really hard to say what's going on. It's a 93 so there may be a lot of miles on it. White smoke is unburnt fuel unless you a loosing anti freeze and you can't find an external leak. Could be the injectors and/or IP has gone about as far as they are going to go. My 93 has 200,000 mi. and the pump and injectors need replacing. I only get excess white smoke on start up.
Robyn
05-11-2009, 19:14
Could very well be that the injectors are dribbling and allowing for excess fuel to slop in an thus the white smoke.

Yank the squirts out and have them checked.
I bet the pop pressure and the spray pattern are trash.

Possibly a fresh set of squirts will heal its Ill's


Robyn
REMF
05-13-2009, 23:12
Took the truck to a shop, they said it has zero compression in the #8 cylinder. He said the motor was dead due to that and it would have to be replaced or re-built.

Does that sound right? I’m no mechanic but I don’t want to get screwed either.

Thanks for any input.
rameye
05-17-2009, 15:50
If you dont have compression you dont have much of an engine...gas or diesel..

The question is why doesnt it have compression?

Could be a valve...doubt it..would be making all sorts of cool sounds!...most likely it something much worse.

If you pull the dipstick is she blowing like hell?

Sorry, It's just not an easy (or cheap) fix regardless
JohnC
05-18-2009, 09:04
Find out why, first.

(Maybe there's a part from the trans stuck in the intake valve... ;) )

OK, it's a long shot, but know the problem before choosing a cure.