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PMD troubles?

J

jrsavoie

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Location
Rural Clifton, Illinois
!998 K2500 Suburban 3.73 gears

We overheated 3 times between Pagosa Springs and South Fork on Rt 160 while pulling a lightly loaded trailer - about 1200 lbs. - plus the weight of the trailer. We were blowing plenty of black smoke.

I'm going to have to jack the trailer up and make sure the wheels were turning freely - though there was nothing to indicate they weren't.

We ran the whole trip at normal temp til the big hill with the trailer.

Subsequently we warmed up over 210 when driving up to Zapata falls

About 2 1/2 hours from home the Check engine light came on. It went back off before I took it to get the code read.

I didn't get the number in history but the code was something like turbo high voltage.

The Suburban was still blowing black smoke when revving with no load.

Other than that it seems to be running fine

We couldn't figure anything else out that would be wrong. The PMD is an older Flight Systems. I'm going to try one of my spare PMDs

I got very lucky on my trip. I tried the spare PMD we had in the counsel and found that it was the bad PMD from the last time I changed it. I must have forgotten to pull the resistor, toss it and replace it.

Any ideas or suggestions? Other than to make sure your spare PMD is GOOD and not the bad one you previously replaced.
 
Air filter was new 5,000 miles ago. I haven't checked it but I haven't been in a bunch of dirt - almost all paved roads. I will check it soon.

I had the same thoughts on the turbo. I haven't hand checked it but when it was on the computer the tech said it was working fine.

Has anybody had a PMD cause black smoke?

Hopefully I'll get to the Suburban in the next few days
 
The PMD usually give you some unexplained stops, and then dies.
Thats what mine did some years ago. It started as poor trottle respond a couple of times, and didnt start after been stopped after that.
 
Had a runaway PMD cause grey smoke.

You need to diagnose the boost problem,a boost gauge would help a lot with that but check the vac lines,MAP sensor and boost solenoid for starters along with the vac pump.
 
racer55 said:
Had a runaway PMD cause grey smoke.

You need to diagnose the boost problem,a boost gauge would help a lot with that but check the vac lines,MAP sensor and boost solenoid for starters along with the vac pump.
Click to expand...

The Tech did that with me watching.

At idle and normal running conditions there is no black smoke. Only when revving

What other things cause black smoke if the turbo is working?
 
Can you check the injectors while in a 1998 or do you have to pull them and get them tested as always?

Any checks for the IP?

I'm leaning towards the PMD so far.

I'll be looking at it in the morning.
 
The best way to test the injectors is to pull them.
But you could try cracking each injector line loose 1 at a time and note how the engine responds-no reaction would indicate a bad injector or low compression.
 
Gotta be injectors....Need to at least pop test 1 or 2.....

Sorry if it's already been asked, but how old/miles/brand/quality on your current squrits?
 
No way, the tech can check the turbo with a computer!!!

I would put a TurboMaster and see if it is still blowing black smoke.
I got the feeling that it is not the turbo itself, it is probably all the parts supporting the turbo.
If you want to keep the vacuum system, make sure you check all the vacuum components like pump, lines, solenoid, etc.

I know I will get flamed recommending TM so be it.
The funny part about it is all the people that follow that suggestion, thank me.

JMHO.
 
The injectors are at least 5 years old. They were rebuilt injectors. I learned the hard way on using rebuilts, I've had to prematurely replace injectors in the 3 vehicles I used them in. No problems in the vehicles with the new injectors.

Where is the best place to buy new injectors? And What to buy?

The vac system was tested with a pump and hooked up with the Burb running. It showed to be good>

The turbo moves freely with engine not running and doesn't move by hand with the engine running.

The smoke issue seems to have cleared up some with the recent tank of fuel.

The fuel filter was in need of a change but not terribly bad. The air filter seemed fine. I blew it from the inside out and got very little dust. Less than I expected, even.

The SES light came back on when I reached about 80 mph.



Brooklyn Tow said:
Gotta be injectors....Need to at least pop test 1 or 2.....

Sorry if it's already been asked, but how old/miles/brand/quality on your current squrits?
Click to expand...
 
Run the vac pump straight to the turbo (Bypass the WG solenoid)......Just join the orange and black lines at the solenoid w/ a piece of rubber hose.....Or just tie the waste gate shut, that'll take the pump and solenoid out of the equation....Or do both methods to eliminate each part of the system.
 
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