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Excessive Smoke

A

Acesneights1

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Location
Northeast CT
I'm getting alot of dark grey smoke on acceleration. If I take off easy ok but hard throttle it belches it out like an Old turned up Mack. No codes. Vac system for wastegate appears to be working. gonna put a boost guage on tommorow but we messed with the timing a few months ago . Could it be timing related or probably lack of boost ? Air cleaner is new. Truck runs fine otherwise and actually seems to have decent power but damn does it smoke under load.
 
4 Inch ex, gutted kitty, no egr. Thanks TD. I'm gonna try to get a boost guage on it as well. I kinda figure it's boost related as well which a TM will solve that problem quickly. I just want to make sure that is what is causing it.
 
OK I put a hand vac pump on the wastegate. It closed partially with 1 inch of vacuum and was fully closed by 2 inchs. it held no problem. When I put the guage on the Vac line I couldn't read the numbers doing it myself but it snapped up well over 10 inches anyway. I tried pumping the wastegate closed with my hand pump and the truck still belched a nice cloud of black and I thought I saw a trace of white but the truck wasn't fully warmed up either. Also when I connect the vac line at IDLE the wastegate very slowly closes even at idle so there is a slight vacuum even at idle. Also I treid revving the truck with wastegate vac line disonnected and it didn't seem to make any difference. I have not been able to drill and tap for a boost gauge yet. This truck is pissing me off. A guy at work is selling an 01 Ram with a 24v and a handshaker. Starting to miss my Cummins.
 
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Sounds like a weak VP to me if you had slight vacuum at idle. Mine would pull the WG shut at idle quickly and it would take a good shove to open it. i had 15 inches of vac at the WG at idle with my new VP.

If you need one let me know.
 
Yeah but should there be vacuum at the wastegate at idle ? Reread what I wrote cause I worded it backwards. I just realized that and corrected it.
 
The PCM holds the wastegate fully closed at idle, so there needs to be 15" of vacuum at idle at the turbo actuator. Check the vacuum line going into the boost solenoid on valve cover. If you have vacuum into solenoid but not out then you just have a bad boost solenoid.
 
15 inches at idle ? I don't have that. it barley had any. It would build 15 inches if I goosed it but idling it barely has 2-3 inches. Now I am thinking more clearly on tis and if the vacuum is weak at idle the waste gate could be opening prematurely and causing the smoke right ? But here's the thing... I manually pumped up 15 inches of vacuum to the wastegate and then went in the truck and goosed it and it still belched Black smoke. I gotta get someone to help me tommorow and goose it so I can be under the hood and see what's moving. I tried to get my 4 yr old to do it but he was scared of the truck.
 
Going by the numbers you've given us, i'm betting your VP is shot is all.
 
You cant tell whats not working right until you break up the circuit. check vacuum right out of the pump, it should be over 20", If not its bad. If it is there then the solenoid is not operating correctly, or a line is broken or cracked (very common).

You probably cant hold a vacuum on it. Otherwise the wastegate would never open, because the solenoid closes the line to the turbo and vents the pump source to open the wastegate. And pressure overcomes it and wastegate opens.

This is exactly what happened to me when a line was cracked. Because when I revved it the vacuum would close the crack or at least pull suction across the crack and turbo would boost high then drop.
 
Even if the waste gate were welded shut it would belch out smoke until the turbo gets up to boost, there is some lag, even with a GMx:rolleyes5:
 
Yeah but mine belches out alot more than a stock truck should. come to think of it it also pulls better than a stock truck should. I wonder if there is a way to tell if the truck has a tune ? I have atM but it's for a GM4. This truck has a GM8 and I need the truck sat so I'm gonna try to fix the vac system if that's what it is, otherwise...Powerstroke to the rescue again...:mad:
 
At idle was getting about 1-2 inches of vacuum at the Pump. I tested all lines, no leaks. also found an ex leak drivers side manifold rear port. It almost looks like the head is worn away. I hope a gasket will fix it. Upon slight throttle truck immediatly builds 15 inchs of vac but not idle.
 
Then that proves it, the vac pump is faulty. Not sure if the diaghrams are repairable, or if you want to bother replacing. I like that system, but I never had a vac pump fail.
 
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