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1983 GMC Jimmy smoking blue

1999gmc

1999gmc

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Location
Carmichael, CA
A couple years ago my daughter picked up a 83 Jimmy with a turboed 6.2L It was kind of lacking power and smoking some at idle and when you would get on it. The truck had an electric lift pump on it that was dead. I put on a new lift pump and all was good. Power was pretty descent, the smoking was gone at idle, and there would be just the usual puff if you got on it, but did not smoke continuously like before. She drove up this weekend to where we were camping, and said after she came up some 6% grade hills and came to a stop, it was smoking pretty bad out the exhaust covering a Prius. And then she said all of a sudden it quit smoking. She said the smoke looked blueish. Said the truck didn't sound any different and was idling fine before and after the bad smoke at idle. Any ideas???? She said exhaust temps never went past 800.
 
What can you say 6.2 diesels hate Prius's... or was the the driver blue smoke cursing over the 'damn smelly diesel'? :hihi:

Recheck the lift pump. Recall they used to have a mechanical pump so hopefully it was removed out of the fuel loop.

I would check the timing. Then check the CDR, oil level, and suspect a turbo oil seal.

Still running EGR on it? If so maybe it sticks open?

Coolant levels fine and steady? Possible head gasket?
 
Mechanical pump was removed for the turbo oil drain, egr is plugged off to install the upper intake for the turbo setup. coolant level is always good, no bubbles or loss of coolant, CDR is new. I did that before I found the lift pump not working. I was thinking the lift pump quit, and then started working again possibly. Guess she can just keep an eye on it if it does it again.
 
I was thinking maybe worn valve guides. Top end might have picked up some extra oil working hard (rpm wise) to get up the 6% and it went thru the guides until it caught up.
 
I have smoked going downhill with a little throttle. Usually downhill sections are after grades like this. maybe it was just clearing this cold precup condition up?

Again I think the timing is a little retarded. Worn chain? Lift pump pressure or vacuum makes a difference on IP timing.
 
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