Crazy start seq. after engine swap

[tankertoad]

Replaced 6.5TD in my '97 dually with 6.5TD reman from rolled '94 'burb. Kept wiring & inj. pump from '97. On start engine cranks over really well but doesn't catch fire for a long time. When it does fire, it immediately revs to about 1500, and then dies! Suggestions? I know, but I'm really low on C4 right now! This thing is driving me even crazier than I normally am. Last week, my oldest son, not smartest, ran his 6.2 ' burb out of fuel and after I rescued him, his diesel acted the same way, but after 4 or 5 attempts it caught and ran normally. I'd like to keep trying mine, but am leery of it not shutting down at 1500.

[DmaxMaverick]

It's drawing in air. The same reason your son's 6.2 did the same thing. You'll have to find where the air is getting in. Usually, it's fuel filter related.

[tankertoad]

Thanks DMAX. Finally got it to fire and it runs really smooth, but have a lot of white smoke out exhaust. Too much fuel? On restart, it takes a few revolutions before it lights, but once it's lit it drops to nice flat idle, good rattle. My son has OBD2 scantool with him out of town this weekend so can't check timing, but no check eng warning. Thanks. Now to figure this white stuff out! John

[DmaxMaverick]

If you haven't ran it much, it could be residual air in the injector lines. This will clear up with some running up to operating temp and a drive. Air in the lines causes retarded timing, and white smoke. This problem is the lesser result of an airlock, but is normal as long as it clears. If you have ran it up to operating temp a couple times, read on.......



White smoke only after a cold start? Or once it's warmed up?

Too much fuel (or too little air) will show black smoke. This as long as the timing is correct with good fuel.

If only after a cold start (where it clears up in less than a minute), could be a glow plug issue, or the cold advance isn't advancing (PCM controlled on the DS4's). If you've replaced the OEM type glow plugs with AC-60G plugs, they will require a longer glow time to reach the same temp as the OEM's. If it starts hard now, it'll be no picnic come winter.

White smoke, if it's fuel related, is unburned, raw fuel. Meaning, combustion temp too low. Could be from low compression or retarded timing. Could also be contaminated fuel.

If the "smoke" has a sweet smell, it's probably coolant, which is actually steam, but looks like white smoke. More info on that if necessary.

At any rate, if there's no indication you have a coolant in the cylinder problem, a check of the timing is in order. If it checks out, then a compression test should be done. All of this, of course, is with a tank of fresh fuel and a new fuel filter (which should be done before anything else).

[tankertoad]

Thanks DMax. My son got home last nite w/scantool, no codes stored. Tried the relearn w/ KOKO procedure, and got code for inj. pump timing offset. PO 1214. Loosened pump & rotated toward driver side, but still smokes white, same code. Tried independent shops in area & only GM dealer and one guy who said he " would have to take it apart first, to make sure that I had installed the pump correctly." Then they would put it back together and scan it! Unbelieveable! Trying to see if any of my friends Know a Tech w/ tool who could make some easy money on the weekend. Other suggestions? Thanks, John.

[DmaxMaverick]

You can't really install the pump "wrong". If you did, it wouldn't run, and you'd likely have a bunch of noises that could make you run for cover. Certainly no reason to "take it apart" (except to get deeper into your pocket). The lines, however, can be indexed incorrectly. Verify your firing order. If you are getting white smoke at operating temp, the compression is low, or the timing is severely retarded, which could include timing chain stretch. (all this assuming you don't have a coolant issue). Worn/fouled injectors could be an issue, but usually it's white smoke when cold, then black when hot. If it's running smooth with little noise, I'd suspect retarded timing. Could be the pump is outside the range of PCM adjustment. At any rate, it should be timed correctly now that you have a mismatched engine and pump.

[rameye]

One other possible reason for white smoke,....if its running nice and smooth. I had a dickens of a time re-starting mine with crapped up injectors...long story short..I had filled up the exhaust with diesel and it took about and hour to burn out the unburned fuel. Plenty O white smoke during the process......

[DmaxMaverick]

One other possible reason for white smoke,....if its running nice and smooth. I had a dickens of a time re-starting mine with crapped up injectors...long story short..I had filled up the exhaust with diesel and it took about and hour to burn out the unburned fuel. Plenty O white smoke during the process......

Certainly a possibility. The same principal used by airplanes at the airshow.