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Jose9640 · 05-02-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

I have this cm870 that has a white smoke at startup. Definitely smells like raw fuel. It will only do it after truck has sat for some time and goes away after about 10-15 seconds. Starts good, idles food. I had done an injector leak test and found 2 leaking so I replaced all 6 injectors. Smokes less but still does it. Can a metering actuator cause this?

Rawze · 05-02-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

age, compression loss, leaky valve seats till it warms up, and/or leaky valve guide seals all can contribute towards it, or a combination of them all. - That is what they do when they get older as the head wears.

Also, if the timing actuators are worn out, it can cause some of it too.

Personally, if it does not cause any problems, no need to worry too much about it.

just my own thoughts on it any ways.

DarrenEW · 05-14-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

Have the same issue with the cm870. Rebuilt engine which hasn't seen anything at all. One of my metering actuators was badly worn so I replaced it. Now it smokes white for about 15 seconds at startup and then it gives a little acceleration and a poof out the exhaust, and then it's good. Also did an injector leak test. Any idea what it could be?

Waterloo · 05-14-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

(05-14-2020 )DarrenEW Wrote: Have the same issue with the cm870. Rebuilt engine which hasn't seen anything at all. One of my metering actuators was badly worn so I replaced it. Now it smokes white for about 15 seconds at startup and then it gives a little acceleration and a poof out the exhaust, and then it's good. Also did an injector leak test. Any idea what it could be?

Could just be water condensation in the exhaust...

DarrenEW · 05-15-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

Could just be water condensation in the exhaust...
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Sometimes it starts and then stops as well only to start rough after I step on accelerator while starting. Could it be an air leak or something like that before the fuel pump? What are your thoughts?

Waterloo · 05-15-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

Do you have an Inline reader and the Insite software?

How old are the batteries?

When it is up and running, take a rubber mallet or screwdriver, use the screwdriver handle, smack the ECM a few times and see what happens. Not real hard, but hard enough to get its attention.

If you have a Davco, and it has been serviced lately, it could be a leaking o-ring too. But in that case, the truck will normally not start, but still something to inspect.

I would start at the batteries, check the connections and chase the wires, especially up to the ECM. Any corrosion, clean it up. Check your connections at the starter too, may be time to run all new cable from the batteries, grounds and power. I had to do that on my 08 ProStar, much of the cable was green. Wiring and cables only last so long.

For a fuel leak, inspect around the IFSM for fuel, you could pressurize the fuel tanks too, I forget the PSI, someone will chime in. Or it could be one of the fuel metering actuators, if one fails, they are probably all due for replacement. They are normally good for around 800,000 miles, if you are there, may be a good time to replace the rest, along with the lift pump. Again, they only last so long...

Sounds more like an electrical issue to me...

Chamberpains · 05-16-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

Was your IFSM rebuilt during the overhaul? What warranted replacing only 1 timing or metering actuator? How do you know that the rest were good?

I'm not a huge fan of just doing something unless its warranted in some way. But you do have to look at the components of an, at least 13 year old piece of equipment and say "ya, its time to pull that apart completely and see if its all still good or maybe its just gonna get rebuilt or replace"

There are check valves and baffles on the IFSM that get clogged and wear out due to dirty fuel over many years and many gallons of fuel. Its not at bad idea at this time to start going over things with a fine tooth comb and freshening everything up.

Here's 2 video of the fuel system of your engine. Maybe they'll guide you in a direction.

Part 1 https://youtu.be/HvvFElrc5ak

Part 2 https://youtu.be/_WeiDC6S8Lw

Rawze · 05-16-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

(05-16-2020 )Chamberpains Wrote: ...
Part 1 https://youtu.be/HvvFElrc5ak

Part 2 https://youtu.be/_WeiDC6S8Lw

For anyone reading this post that is interested in keeping these videos handy ... Youtube has been known to block/hide red engine training videos like these on and off for unknown reasons including the one's linked above. I would suggest u get a download helper and keep local copies of any official training videos like this for future use, just saying.

DarrenEW · 05-18-2020, **(Subject: Cm870.white smoke, raw fuel smell )**

(05-16-2020 )Chamberpains Wrote: Was your IFSM rebuilt during the overhaul? What warranted replacing only 1 timing or metering actuator? How do you know that the rest were good?

I followed rawze's instructions on how to check if they're worn out and cleaned them. The one metering actuator was really bad. After I replaced it with one that is still good, it started and ran a lot better.