new 700R4 then Black Smoke

[rjerniga]

I have an 82 6.2L Chevy PU with a new (rebuilt) 700R4. My old 700 just quit working so I swapped out this new one.Problem is;I noticed black smoke
coming from the tailpipes as soon as I started off, so I returned to the shop; they kept it another day but when I picked it up they said "its an engine problem,nothing they did installing the new transmission". So now I have tried :
1) disconnecting EGR and EPR - no change in smoke
2) rewiring lead from trans to TPS - no change
3) new filter and fluid - no change
4) new TCC solenoid - no change...this engine did NOT smoke until transmission swap..doesnt smoke at idle..Could it be the TPS? Thanks for any help!

[gmctd]

Likely it's to do with the vacuum hoses and EGR.
700R4 is mechanical shift control via throttle cable.
Check vacuum with gage, then rubber hoses and such - most likely to be disturbed while R&R'ing TV cable.

[ 01-20-2004, 12:07 PM: Message edited by: gmctd ]

[arveetek]

As was stated, about the only thing the tranny swap could have done was mess up the EGR system. Black smoke indicates too much fuel or not enough air or both.

The TPS only controls the lockup torque converter, doesn't have anything to do with fuel regulation on the engine. As does the TCC solenoid, it wouldn't have anything to do with the black smoke.

How much smoke are you talking about? It's normal for the 6.2L to blow black smoke under load.

Casey

[britannic]

Another thought: if the old tranny, convertor and TC C (assuming this was replaced) were worn and slipping, it may be that your engine isn't revving as high and it loads up more at lower revs. Does it smoke in all gears?

[Deib]

Just a guess, are you sure it is taking off in first gear??
If not that will lug the engine and cause black smoke.

[rjerniga]

Thanks for all the quick responses! I'll try to
answer some of your questions. I have tried plugging
the vaccum lines, bypassing and even removing the
EGR without any noticeable change in smoke.
Smoke is Med/Heavy under no load; way past normal.
It smokes in all gears; but not at idle or at shift
points between the gears.I'm pretty sure it starts
in 1st gear and shifts smoothly thru overdrive but
one last thing: if I'm going 35 to 45 mph and really
"step on it" transmission steps down but just slips...will not shift until I let up and battleship
fogging black smoke everywhere....Thanks

[britannic]

The tranny may be a red herring and therefore a coincidence. There may a real possibility the timing is off; when they installed the tranny, is there any chance they accidentally squashed the return line somehow, so that the restriction has retarded the timing?

Is the TCC locking in 2nd and 3rd at all?

Is that new tranny set up for a 6.2L diesel, is it shifting too early, or is it too late? Shifting too early can load the engine up more and lead to more smoke. Is the transmission binding at all? What about the brakes are they free, or binding?

Have you checked the air filter for restrictions?

Thinking logically on conditions that cause black smoke:

</font> Over fueling caused by not enough air, either because of restriction in the air intake or the IP turned up too much for the engine's air capacity.</font> Timing too retarded or too advanced; really retarded timing can result in unburned fuel (white smoke) during start up. A restricted return can cause over retardation. Too much advance can be caused by a sticking light advance mechanism, or return check valve that sticks open.</font>