New Injectors And Now I have Smoke

[1629dill]

Spent two days changing the injectors and glow plugs on my 6.5 and it still works. My wife did not think it was a good idea for me to be taking on a project that involved taking so many parts off the suburban. The suburban is her daily driver and I only get to drive it when it needs to go to the gas station or after I do surgery on it. To day on the way to work I noticed that I was getting more black smoke when I would accelerate from a stop. Other than that the motor sounds about the same just a little smoother. I am wondering if I did not put it back together correctly or do I have some other problem that I now have to fix.

[More Power]

What sometimes happens is some part of the vacuum system is disturbed during unrelated service work, which then affects the turbo boost pressure. Carefully go over the vacuum lines running from the vacuum pump up and over the engine to the wastegate solenoid, then from the solenoid to the turbo wastegate actuator. Check for vacuum at the actuator. Normal vacuum is 18 to 23 inches of vacuum when measured at the actuator with the engine idling.

Jim

[suburbanK-2500HD]

I guess you should not be able to easy move the wastegate rod when engine idles.
If you do, there is no vacuum.

[suburbanK-2500HD]

Spent two days changing the injectors and glow plugs on my 6.5 and it still works. My wife did not think it was a good idea for me to be taking on a project that involved taking so many parts off the suburban. The suburban is her daily driver and I only get to drive it when it needs to go to the gas station or after I do surgery on it. To day on the way to work I noticed that I was getting more black smoke when I would accelerate from a stop. Other than that the motor sounds about the same just a little smoother. I am wondering if I did not put it back together correctly or do I have some other problem that I now have to fix.

what was the reason for changing the parts ?
What is your km/miles on the truck.

If you get dirt in one or more injector it could be spraying in the wrong pattern.

[1629dill]

What was the reason for changing the parts ?
What is your km/miles on the truck.



The reason for the change was some smoke at startup and raff idle for the first 30 - 45 seconds after staring when cold. After install it has not smoked at startup and no raff idle. The suburban has 175,000 miles on it.

[1629dill]

What sometimes happens is some part of the vacuum system is disturbed during unrelated service work, which then affects the turbo boost pressure. Carefully go over the vacuum lines running from the vacuum pump up and over the engine to the wastegate solenoid, then from the solenoid to the turbo wastegate actuator. Check for vacuum at the actuator. Normal vacuum is 18 to 23 inches of vacuum when measured at the actuator with the engine idling.

Jim

I checked the vacuum tonight and found that I only have about 4 in Hg at the turbo waste gate vacuum line. I could not see any breaks in the line and was confused with the low reading at 1000 RPMs. Is the vacuum pump bad or is there a leak some place else in the system? Any way I look at it I will be learning how the vacuum system works on a 6.5.

[chevytuff]

Like more power said previously you probably disturbed the vacuum lines during the R&R of the Injectors. When I had my 95, The hard vacuum lines became brittle and during one of my repairs they cracked. I couldnt find the break for a while and ended up removing the line. The line broke shortly before where it inputs into the wastegate solenoid Was able to fix it with some heat shrink tubing. The breaks on the hard lines are hard to see until you move the line. Just be careful because they are brittle. You might try pulling the line at the actual vacuum pump and take a reading from there. If it is still that low I would suspect its the pump, if its normal then the lines.

[Robyn]

Check the vacuum right at the pump, it should read 26" and steady.

Now check the vacuum at the line where it connects to the solenoid.
If there is a difference, the line is the issue.

If the reading at the pump is not steady (needle on the gauge wobbles) then the pump is bad,]

If the line are cracked or broken, you can replace these with rubber vacuum hose if you cant find a hard line set.

I have used Rubber hose, hard nylon air line (such as found on industrial stuff) and even small copper tubing will work. Just connect with a rubber jumper hose to the waste gate, the solenoid and the pump.


Readings at the turbo wastegate actuator should be around 15" with the engine at idle

Unhook the vacuum from the wastegate, check it for free movement and then leave the gate lever to the rear.

Hook the vacuum up and the gate should close firmly. If it does not the gate actuator is bad.


Good luck

Robyn

[JohnC]

Also, make sure the vacuum pump is connected to the solenoid fitting with the restrictor in it (front?) and the wastegate connected to the unrestricted fitting.

[1629dill]

I have checked for vacuum on the line that is coming up to the solenoid from the pump and have the same vacuum reading. I can not get my hand down to the pump to get a reading at the pump, so I am thinking I may need to replace the pump.
So I have been looking around the online sellers and have come up with this question. Why am I seeing such a large difference in pricing on vacuum pumps? :confused: I have found a Dorman Vacuum Pump Part Number: 4150-07057869 for $95.54 online and a Delphi Engine Management Part Number DEMNLVP3450 at NAPA for $174.00. Is there that much of a difference in the parts out there?

[16gaSxS]

When my vacuum lines broke the dealer could not find them on his system, I simply put a manual (TurboMaster) waste gate controller on removed the vacuum pump and put a shorter belt on. You can then set the Max boost pressure where you like (within reason). You should have a EGT and Boost Gauge though. Less stuff to fix.