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Diesel ?

Brian H

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Joined
Mar 28, 2006
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I bought a 97 gmc 3500 box truck with the 6.5 turbo diesel in it. When I give it more than half throttle and the turbo boosts it smokes black really bad. Is it not getting enough air or to much fuel?
 
I'd have to see that.. How much is a lot? For something like that. a bit doesn't seem like it'd be too abnormal. I don't know too much about what goes wrong with the chevy's. But I'd atleast make sure she's breathing well. Intake is clean. Exhaust isn't plugged up. I remember when my Grandpa owned the truck I have now. He would lug it EVERYWHERE. When we'd take it out for a drive. we'd hit the throttle (bone stock) and it would just billow out smoke. It'd eventually clear up and run clean.
 
I've seen this happen when the pipes and connections between the exhaust and the turbo are leaking or the pipes between the turbo and the intake. If possible you can look for very faint soot marks at connections.
 
Lucky Jeff said:
He said it's when the turbo starts to spool... If it was a leak, he'd notice smoke before it even started to spool.

Exactly, the more pressure (spooling turbo) the more it leaks and the more out of balance the fuel/air ratio gets.
 
PORTER said:
Brian, you hear the turbo spin up?


Well i really cant here the turbo spool up but i can feel the difference in the power so i was just guessing that it was spooling. It does seem to have a bit of and exhaust leak somewhere by the turbo but there is not any any build up in the area that the little noise is coming from.
 
I gotta 6.5 in my 95 suburban with 180K. Never had a problem with the motor. Gone thru several vacuum pumps and fuel pumps. You will never hear the turbo spool up. If you do the bearings are going out or the turbo is going bad. I blew a head gasket at 97K and the warranty replaced the entire engine, plus I got the old one for parts too. Still on the original tranny. Never rebuilt. Used to tow 8K with it regularly. Now it is just the family taxi. The Powerstroke took over tow duties.

Enjoy it. Check out www.62-65-dieselpage.com for more info.
 
So its still is blowing lack smoke.Vacuum presure is only 6" and the waste gate at and idle. What else could it be?
 
This may help Found it on iatn. Sorry about the long post.
1995 Chevrolet Pickup K3500

Engine: 6.5 L / 395 CID / 8 cyl / Diesel / OHV
Fuel: Fuel Injection / DIESEL
Ignition: Not Applicable
Trans: 4-speed Automatic Transmission (Electronic)
Mileage: 180,000 mi
Emissions: Not OBD-II Compliant
VIN: 1GBJK34F0S

Misc Data: TOWTRUCK
Symptoms: Excessive Emissions, Surge, Misfire
Occurs: On Accel, Cruise
More Info: Test results & repair history included below

_____________________ ORIGINAL MESSAGE _____________________

this is our shop towtruck with a 6.5 liter diesel with out
egr. when you accelerate it blows excessive black smoke out
the exhaust. if you accelerate real slow it doesn't smoke at
all. we checked boost pressure under accl. and it gets to
about 8.5lbs. under heavy accl. we checked it with the monitor
and with an actual pressure guage and both readings were the
same. intermittenly the check engine light will flash under
heavy accl. but it rarely happens. it is a code 35 which is
injector pulse width time to short. we have mitchell-ondemand
5 and it doesn't give me any info on itermittent code 35. if
it was a current code it pretty much comes down to it being a
fuel solenoid or the pcm. another problem that we have is when
you get above 2000 rpm the transmission unlocks and the
accelerator pedel is extremly touchy. it's hard to keep it at
a steady speed. you press the pedel and it takes off to fast
so you let off a little and it drops way down in rpm like
their is no midrange when your in the 2000 rpm to 2400 rpm
range. its either 2400rpm or 1700 rpm you can't get it to stay
steady in between them rpm ranges. i checked all the throttle
position sensors on the monitor and they seem to all read good
with no open spots in them. it will lock up like it should
when you're under that 2000rpm range. i watched the throttle
angle when driving and it is normally around 4% to 8% when
cruising below 2000 rpm if you try cruising at like 2300 rpm
the pedal gets real touchy, the transmission normally comes
unlocked and the rpms start to raise on their own and you can
actually be at 3000rpm and only 1% or 2% throttle angle. the
pecentage seems correct because you are barly touching the
accl. pedel. one of my employees was getting ready to do a tow
last week and when he hit the accl. pedel it went to like 1700
rpm and stayed there even after he let off the pedel. its like
somehow it is getting extra fuel. we did notice that the seal
on the turbo must be leaking cause the intake is oily on the
inside, so maybe its burning the oil from the turbo causing
the smoke and causing the throttle angle to be so low that the
trans comes unlocked. but the motor uses very little oil. this
vehicle had a new injecter pump put in at the gm dealer about
4 years ago so it does have the updated pump. also in the
colder(like 40 degrees f) weather when you start it up at
first it will miss for a couple of minutes and then it comes
out of it and runs smooth. smoke problem and accl.touchy
problem came at same time. any ideas would be greatly
appreciated

___________________ TEST AND REPAIR DATA ___________________

MANIFOLD VACUUM READINGS

Idle: 18 in.

COMPUTER CODES AND DESCRIPTIONS

35 - INJECTER PULSE TO SHORT OF TIME

RELATED REPAIR HISTORY

new injector pump about 4 years ago. rebuilt motor a year ago.

____________________________ FIX ___________________________

thanks to all that responded. i rechecked the APP sensor
reading manually and they checked out good. so i looked for
ways that i could get extra fuel and have this run away
throttle feeling like it does. i removed the cdr vavle and
left that unhooked and that was what was causing the oil in
the intake manifold that i had seen, but it still didn't fix
the problem. i finally found the identical problem in the fix
database and that guys fix was an injector pump.in his replies
i found one that states that the normal fuel rate at idle on a
warm engine should be 10 to 13 mm.i checked mine and it would
bounce around between 2 and 4 mm at idle. in his post he
stated that the pumps wear out and bypass internally causing
this run away throttle feeling.when i called around looking
for a pump i talked to a guy that actually rebuild these pumps
and he informed me that it was a commen problem with these
pumps.works great with new pump and trans locks up correctly
now that you actually have to push the accel.pedal down
farther than 1 or 2% when at cruising speed. my close is also
in the replie section by mistake. thanks again:mad: :mad:
 
Now yet another problem. After driving for awhile and then turning it off. When I go to start it (Within 10 to 20 minutes of it being off) it will start up and die.Then it will start up and run fine. Yesterday after driving for awhile I had to stop and deposit some money in the bank .When i went to leave it started and died 5 times. The 6th time I floored it and it ran fine after that. Whats the deal yo? Bad connection at the fuel shut off switch. I know theres not much to keep a deisel from running.
 
I was also told that where the fuel pump is positioned on the top of the engine will cause the fuel to boil in the pump after it has been shut down after a long drive.So when I go to start it the fuel causes the engine to run funny or start hard until that fuel has run through the system. Is this true?
 
Brian H said:
I was also told that where the fuel pump is positioned on the top of the engine will cause the fuel to boil in the pump after it has been shut down after a long drive.So when I go to start it the fuel causes the engine to run funny or start hard until that fuel has run through the system. Is this true?

Nope-----false...


You need to swing by schmucks or who ever and make sure you have no codes pertaining to the injection pump.. Also verify your lift pump is working (on the inside of the frame rail drivers side right about where the back of the drivers seat is)...
 

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