Start up Smoke

[zeuss]

Originally Posted by cleatus12r

My truck has always smoked for the first 5-10 minutes after a sub 15 degree start. It was -31 here today and it started right up.....but smoked pretty good until I left the house 20 minutes later. I've also got 130K on my truck and it DOES need injectors.

The glow plugs are on for 120 seconds when the engine is that cold. Once they turn off, the engine is relying on compression heat to burn the fuel efficiently.

The smoke, if it smells like raw diesel fuel, IS unburned fuel. The stock setting on the chip DOES NOT use the original PCM for anything.

I replaced the glow plugs in my friend's truck about a month ago....even though they tested fine by every measure of the word. The difference in cold starting is night and day.

Does this problem I am having sound like a injector issue. It seems to me if I am still getting 15 to 17 this time of year they can't be to bad. I will also say that I am on my 3rd relay in 12,000 miles. So I wondered if even though they tested good there could be a problem. ( More resistance equals more aamps) I didn't ask how they tested them. I have thought about changing them anyway.

[zeuss]

I will also see what happens in mornig without chip in. This is the first winter I had the chip in and also the first winter I had this problem.

[907DAVE]

Like Cody said, the glow plugs are off after 2min or less and should not cause excessive smoke after a few minutes............ but there is definitely an issue there if you keep changing relays.

My truck and many other trucks I have been around have always smoked for quite a while when cold.

Does anyone know how long the Air Intake heater stays on for?

Might be worth looking into.

[zeuss]

Originally Posted by 907dave

Like Cody said, the glow plugs are off after 2min or less and should not cause excessive smoke after a few minutes............ but there is definitely an issue there if you keep changing relays.

My truck and many other trucks I have been around have always smoked for quite a while when cold.

Does anyone know how long the Air Intake heater stays on for?

Might be worth looking into.

I had resistance tonite on the aih. I don't think the aih comes on while the gpr is actuated though.

[907DAVE]

No.... but it's intent was to reduce cold engine emissions...

[zeuss]

Originally Posted by 907dave

No.... but it's intent was to reduce cold engine emissions...

I'll have to check it. I'm interested to see what happens in morning withuot the chip in.

[zeuss]

Well it smoked like heck til warm again. Pulling chip did nothing different, just took it out of equation. Next questonis could the glow plugs be bad even though they tested good for them. Not sure how they tested them.

[cleatus12r]

Usually glow plugs are only tested by putting a test light to the terminals. The clamp will go on the positive battery post and the pointy end of the light will go on the terminal for each glow plug. However, this test is pretty hit-or-miss and the proper way is to check the resistance.

My friend and I were bitten by the resistance check though about a month ago. All glow plugs tested good on a cold engine. Once current was supplied to the glow plugs though, some would go open (no continuity through them and hence no heat) and he would have a hard start and rough running once it started.