Cold weather and smoke when starting

[eembry]

Seems every winter for about the last three or four winters I have this problem then the weather gets warmer and the problem goes away and I forget about it till next winter. It's the dreaded smoking and chugging when starting cold. I have noticed something different this year though that may shed some light on the problem if I only knew how to read it but I don't know that much about the 6.5. I have changed the injector pump the injectors glow plugs and glow plug controller all within the last 2500 miles. The reason was to try and get rid of the excessive smoke and chugging at cold start. This year I tried starting without depressing the accelerator prior to starting. It actually starts better this way but as soon as you depress the accelerator it actually runs rougher for a little while then clears out. I feel sure it is a sensor or something but I don't know which or where it is. The truck runs great after you get it going and even if you plug it in and let it heat it starts perfect. But it use to start the same way cold. The truck is a 1992 2500 6.5 with 131,000. Serviced regularly, motor seems to be in great shape. I have owned the truck since '96 and it had 80,000 on it when I bought it. Sure would appreciate some help to get rid of this smoke. Also if it makes any difference it doesn't use oil so the smoke is not oil smoke.
Thanks in advance for any help. Eddie

[rustyk]

This is a complete WAG, but I've had a similar issue with the AMG 6.5L TD in my motorhome and the 6.9L NA in my Ford van.

The problem with the 6.5 - after replacing glow plugs (which were from the original engine, so they needed it), controller, and lift pump (which also was bad) - the culprit was ugly battery grounds on the engine.

The Ford's 6.9 had similar symptoms, but the problem with it was the injector return lines' sucking air when the engine stopped.

[DennisG01]

Even though you replaced the glow plugs recently, I'd still check them out - especially if you replaced them with the "quick heat" type. Checking the plugs is always a good place to start. One or two bad plugs can give the exact symptoms you are talking about.

[eembry]

Actually I have had this problem even since I replaced all this equiptment I for got to state this in the original post also I replaced both batteries at the same time as the rest of the work. I know there are a couple of sensors in the block that help control this stuff and I wonder if it would be cheaper to just replace these and see if it will help. I took the truck to a shop that was suppose to really good on these engines after installing all the new parts because I was told it was probably sitll in the pump but they checked it out and said the pump was good the next thing he was wanting to check was compression . I amy be wrong but I don't think this is the culprit because of the way the truck runs the fact it doesn't use oil and it runs great if you either use the block heate or if the tempature is decent. It's only when it is really cold. I espically think the deal with the acting up when you hit the accelerator after starting instead of before is a key to what's causing the problem I just don't know which sensor would have something to do with this.I do appreciate your efforts to help. Anyone else got any suggestions?
Thanks, Eddie

[diesel65]

Check your injectors, I just went through the same problem your having.
I was able to find the bad injector and swap it with a used unit to buy me time till spring when I need a new set
I have 131k miles on my truck.
Pull your cross over pipe, with the truck cold have someone start it and see which bank is smoking. After you isolate which bank is misfiring then each day crack a injector line to see which injector is not contributing causing the white smoke.
I was lucky that it was the drivers side to crack the lines.

[DaveBr]

You might want to check out your lift pump circuit. The lift pump should start working when you turn your key to the crank engine position. If it isn't working then your engine will do exactly what you are describing untill your OPS has enough pressure to start the lift pump working. When it's cold the fuel is thicker so if your not using a good diesel additive you should consider it.

[john8662]

Check for any diesel fuel leaks, if you smell diesel fuel smell under the hood, chances are you have a small leak, which lets some air into the system. This is especially obvious in the cold.

Ditto on the holding the petal. The mechanical injection pumps (like your 1992 and all 6.2's) don't start the engine as well as the later electronic pumps. The best way to start is to turn the key on (glow plugs on) push the petal half way and release (enables the fast idle solenoid to hold throttle), you'll feel a slight click on your foot. The light goes out, crank it till it's running. If it misses a little bit just let it finish and it'll smooth out. Seems that when you give it more fuel it just seems to put out the fire a little bit. If it starts then dies, turn the key off, wait 30 seconds, repeat the process above (including the petal part).

As mentioned above worn injectors (any with over 100k miles on them) and any air leaks in the system, or a failing or non-functional lift pump will hurt starting performance.

J

[Robyn]

With 131K on the beast the timing chain is going to have some wear.
The IP timing is going to be lagging a bit.

If you loosen the three nuts on the IP and advance it about the width of the scribe line on the housing (Maybe a tad more) your issue may resolve itself.

With new injectors/plugs and IP you should see a good running engine.

With timing slow these little critters can get very smokey at cold start and also will be a tad sluggish even warmed up.

You can lose 3-5 degrees of timing easily with a badly worn chain.

Now this said, a fresh chain is "Usually" all thats needed to bring things right up to snuff.

I have had several engines apart that although they had a Bazillion miles the sprockets were fine and just the chain had stretched.

You can replace the chain of a warm Saturday without too much bother.

Yank the accessories, water pump and the front cover.
Be careful of the pan seal area and clean and regoop it well with silicone after replacing the chain.

Best

RC