Excessive smoke & missfire

[R. Spence]

My '96 / 6.5 TD is putting out loads of black smoke at low speed. It seems to clear when the turbo kicks in.(1500 rpm) Below 1500 it is sluggish and when it hits 1500 it feels like you have mashed the excellerator to the floor.
It has on two occasions while running at steady throttle rattled like a gas engine spark knock and blew a large cloud of black smoke.
Is this dirty injectors or do I have an EGR problem as well?
EGR replaced last spring as well as all three solenoids. (Boost-EGR-Waste/dump)

Bob

[More Power]

Sounds like an EGR problem. Any codes?

Jim

[R. Spence]

The SES has not came on, so I did not check for codes. I will go out and check for codes.

Thanks,

Bob

[R. Spence]

I just checked for codes and there are none stored.

Bob

[RJ Performance]

Sounds like your turbo might be going. The black smoke is either from over fueling or not enough air. If it clears up like you described I would think that might be the problem.

Thanks,
Jonathon

[R. Spence]

I just discovered the EGR is not opening. I put a vac gauge in the line between the solenoid and the EGR. Went for a 5 mile ride and had no gauge reading at all. The EGR opens and closes when operated by a hand pump.

I have plenty of Vaccum (30in) at the pump and at the first of the three solenoids. Havent checked the input side of the EGR solenoid yet.

What sends the voltage to the EGR solenoid?
Does the solenoid activate at any temperature or only in running temperature only?

Thanks,

Bob

[R. Spence]

Vaccun line to the EGR has been replaced and EGR is operating properly.
Boost is working as per GM specs.
The black smoke ans missfire problem still exist..
Any ideas?

Bob

[ECMProgrammer]

Have you checked the vacuum supply at the wastegate ?

Lyndon.

[R. Spence]

Lyndon,
I have not put a gauge on it yet, I just observed it changing position as the engine started and assumed it was ok..

I did check the waste gate actuator with a hand pump. Movement was good as well as a standing test for 15 min.

What kind of reading should I expect?

When I put the gauge on the main line from the pump it was doing a little dancing but it was staying between 21" & 22".. Could be the gauge??

Bob

[R. Spence]

Problem solved.
Replaced 3 vac lines and there is a real difference.
The pump is next. One time the reading at the pump is 22" the next time the needle on the gauge dances with 3"-6" fluctuation.

Bob

[Robyn]

The pump should show 26" HG and be steady. The system on these is very sensitive anyway and when the pump goes away the whole thing goes south.
The 1500's may be more sensitive though with the more complex emission system.
Im not sure if these use an EPR valve to get exhaust over the top during Idle or not but if they do make sure its working right.

The turbo wastgate actuator should have good steady vacuum at idle.
Full vacuum there is normal. Once the system reaches max boost the system pulses the vacuum to allow the waste gate to blow open and hold the boost in check.

The problem with these setups is the boost can fluctuate a lot due to the pulsing action of the wastegate.

Idealy the waqstegate should open just enough to limit the boost but yet keep it steady.

Heath diesel has some interesting point on this subject at their web site.

The turbo master is by far a better way to handle this issue.
You can tailor the boost to come on and hold steady just where you want it without all the vacuum and electronic gadgits that give all the grief..

Good luck and glad you are getting a handle on it.

Robyn

[R. Spence]

Robyn,

The EGR appears to be working as well as expected until I change out the vac pump.
The emission system on this truck has been a royal pain from the start. 190,000 miles later and it remains the same. (reminds me of a 57 plymouth)

This is my first diesel and other tham the emission system & oil line drips, I have no complaints. Although I would rather work on my TPI '87 Choo-Choo SS Elcamino.

Bob