LB7: White smoke on winter startup only

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
Hello all. I'm having a problem with my 01 lb7. 2 years ago, after just buying my truck, I had all my injectors replaced under warranty at my dealer. It was making engine oil and the balance rates were out of specs according to the tech 2. At the time of replacement it was also barely surging at idle and the mech. said to run standyne injector cleaner and it might clear it up which it didn't, maybe. He also said that the pump was working fine and he recommended at that time not to replace pump or regulator which I was content with.

Just under a year later while the injectors were under the replacement warrenty, I had the injection pump and regulator replaced by them cause it was starting to surge more. Pump and regulator were replace (last January) and while driving home from dealer (about 5 miles out) truck blew huge smoke cloud, loud niose, and barely running and wouldn't start again when shut off. Towed back to dealer. They said that the pump must have gone bad, it blew the tops off off the injectors ( I thought that they said only the drivers side bank was affected) and they replaced the fuel pump, regulator, and all the injectors under parts warranty.

When the mechanic was test driving the truck to give back to me, the same thing happened again, loud noise, huge cloud of white smoke, and truck sounded like it had many rods knocking. Shut off and wouldn't restart. Towed back to dealer and tore down and the left bank injectors tops blew off again. After much examination, it was determined that the banjo bolts on the left bank, on the fuel return, had somehow bottomed out and was restricting the flow and that was blowing the injector tops off. Mechanic then again put new, I don't know what to call them but they are kind of like a double banjo washer on the banjo bolt and also a washer to keep the bolt from bottoming out. This banjo bolt has bumps at the bottom of the bolt we assume to let flow into the bolt. He then replaced the bad injectors(we don't remember if they were new or others he replace the second time from the right bank, but the truck ran fine like it did before the first injection pump and regulator were replaced. It was kinda warm when I got the truck back and a few weeks later, I noticed a puff of white smoke, diesel smell, after sitting all night when it got below 40 degrees at night.

I took the truck back ( still last winter, Jan-Feb) and they scanned everything and all the balance and return rates showed fine. He said that his Tech 2 and the lb7 couldn't check these when the engine was could cause of the computer in the truck wasn't set up the check when cold, but the newer truck you could. Said to drive it and check mileage and see what happens. I also had him replace all the glow plugs at this time cause some were bad. It still would puff white smoke just on startup after sitting all night when cold outside.

Fast forward to last week or so. When I start the truck when below freezing, the truck puffs white smoke just on startup when cold outside and clears right up even while idling cold, just puffs for first 2 seconds.

I'm taking it back in Dec. 14th for them to look at it before my parts replacement warranty is up in January and would appreciate ANY help to figure out why its smoking at startup when cold outside. As a side note, when it start my truck when engine is cold it has ALWAYS taken 4.0 tos 4.5 seconds for the glow plug light to go out and them I start it. The last couple of weeks, the glow plug light now takes from 4.5 to 6.0 seconds to go out before I start it when the engine is cold no matter what the outside temp is. Also since last year when the injuction pump was replaced my fuel miliage seems to have gone down about 1-1.5 mpg. I suspect one or two injectors are bad, but how do you determine which one or ones and could it be something else?

I would really appreciate help!!!!!!!!!! Sorry for the long post.

Thanks Rob
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
Thanks. There is no oil level increase and no fuel smell. The "ghetto" washer was installed because the Factory banjo bolt would bottom out with the factory u shaped washer that seals both the top and bottom sides of the banjo fitting and the hose end banjo fitting was loose. If this was the area of leak, and was outside of where the injector sits and if not mistaken is on the outside of the head, how could the fuel get into the cylinder to cause smoke only on cold startup? This fitting is for the return fuel from the injectors. Last year when he did this work, he checked the head for return flow and the only restriction was when he bolted the banjo bolt and banjo fitting for the return line up and then there was no flow. This was tightening to specs. On this part could the head not have been drilled deep enough to allow this bolt to bottom out and cause the restriction.

Actually, I think there were 2 problems. One, the return fuel being restricted after the first pump was replaced causeing the injectors to blow and second, after the return problem was fixed, I'm now having smoke problems with the injectors. Since they only do it when its cold outside and first started, how do you check them at that time. Is there a way?

Thanks
 

Vrabel

TOYAHOLIC
May 22, 2008
3,434
0
0
57
Hewitt, NJ
pull glow plugs, pull injector fuse. crank motor. if you have fuel spraying out hole you have an injector sticking.
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
One other thing I just remembered. Since I got It back last winter, I also noticed a slight rough idle when first started and cold outside. Clears up after a few minutes of running.
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
will try that. Also if I have a bad glow plug, will that cause the wait to start light come on and stay long like I stated in original post.??????
 

Duramax_JP

Active member
Jul 3, 2008
1,088
0
36
One other thing I just remembered. Since I got It back last winter, I also noticed a slight rough idle when first started and cold outside. Clears up after a few minutes of running.



Does the rough idle kinda sound like a chugging sound?


Mine has started to blow white smoke at startup and will kinda chugg for the first few seconds after startup. dont really know what the deal is but I dont have time or money to go searching for the problem so I havent messed with it.
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
Yes, actually it does sound like that for about the first 2-3 seconds and the rough idle continues for a few minites. The rough idle is only a little bit, but noticable.
 

RENODMAX

Dead Wrong
Mar 4, 2008
3,602
0
0
Mine did that today. Even blew a little black smoke. I chalk it up to it being a diesel and it was -11 last night
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
RenoDmax, I would chalk mine up also, but It just didn't do this before the injetectors blew. Still looking to see if there is any way to check injectors when cold. Possibly with EFI live or PPE standard?
 

Duramax_JP

Active member
Jul 3, 2008
1,088
0
36
Try adding a fuel additive and see what happens. Ive noticed when I add diesel kleen or STP diesel fuel treatment the problem is almost nonexistant and it runs much smoother.
 

Ben46a

Wannabe puller
Sep 4, 2006
275
0
0
41
Waverley, NS, Canada
When its -20 My LLY fogs out the neighborhood on high idle. When its cold theres going to be some incomplete combustion in almost any diesel. Especially if you have a different tune then stock loaded in. I found my PPE quite bad for this compared to others but my EFI tune is bad too since i havent tried to dial it out. If your only getting a puff id say its a non issue.
 

duramax-rob

duramax-rob
Nov 26, 2008
98
0
6
mt. home, ar
I never thought about it, but I am running my ppe on the 90 hp level. I will try to set it back to stock and see what happens. I thank you all for your responses. I run standyne fuel additive ALL the time. Get a little expensive, but I would rather do that than blow the moter or injectors. I'm still wondering since my miliage has dropped 1-1.5 if it could be the injectors andis there any way to check the return rates while cold. I can do it with my PPE, but it doesn"t seem to coenside with the tech 2. Can efi live check them while they are cold? And can the PPE check them while they are cold? Also does anyone know if its true that the tech 2 cannot check the balance rates and return rates when cold cause its on an enriched setting? Is this right about the lb7 computer?

Thanks
 
Last edited: