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Cobbler
05-01-2008, 19:43
When I was setting my timing the other day and went to far the wrong way and it ran really bad and would barely start - lots of white smoke while running. I noticed that if ya gave it enough throttle it would start running fine and rev freely. It seemed like anything around 1800 or more it would run fine even though the timing was way off. I am wondering if there is some kind of default it goes to at either a particular rpm or throttle position if there is a problem.
The reason I ask is it runs like crap and misses badly in the morning, but comes out of it if I really get on it - then will do it again a light throttle.this continues for about 10 minutes of driving then clears up.
I have read complaints on forums of others with similar running problems missing and smoking then ok under heavy throttle/higher rpm.:confused:

Kennedy
05-02-2008, 16:53
As engine speed increases the timing advances for one thing. Then there's piston speed vs cylinder pressure, and possibly more residual heat (less time between combustion events) in the head/piston/chamber.

mtnbikerealtor
11-06-2008, 11:41
My truck is freshly rebuilt (5k). Stud girdle, reworked heads, full cooling upgrade with dual thermostats and KD Fan/clutch. Remote PMD etc....It runs great at idle and full throttle, but light-footing around at 12-1400rpm, it misses and SMOKES. Blue/white...unburned diesel and smells bad. Do I have a computer/timing issue? I already put new injectors in and it did not improve. Since a chip technically reprograms fuel rate and timing advance etc....would that fix my problem without me having to trouble shoot any further? Any help would be appreciated! Thanks:confused:

1995 GMC 2500 4x4 6.5TD Dual Thermos, Stud Girdle, KD Fan & Fan Clutch, Remote PMD, #9 Resistor, Boost and PYRO Gauges, Turbomaster Wastegate,

DmaxMaverick
11-06-2008, 12:18
Try a #5 resistor, and verify your TDCO is between -.5 and -1.9.

mtnbikerealtor
11-06-2008, 12:34
I am not sure what TDCO stands for...??

mtnbikerealtor
11-06-2008, 13:25
OK. I understand TDCO is "top dead center offset". Let me give you a little more info to see if you still think I need to check that... My dad & I rebuilt the engine and it was flawless for a few thousand miles....(I think I have a bout 7k on the rebuild now) then one day I noticed it acting sluggish from a light take off and then noticed it missing at light load 1200-1400rpm driving. When it does this, it smokes really badly smelling of unburned fuel... I can accelerate heavy and it is fine, just a puff of black and it will clear back up. I am running the phaser gear drive timing set, but I was running it (since the rebuild) before the problem showed up...no changes made that might have caused the problem...We cleared any codes this morning, then drove it. Now there are no codes. Any suggestions?