White smoke during acceleration

[BionicTiki]

I have an 89 Suburban with 6.2L 700R4 Trans. It starts and idles and revs fine in neutral and park but when I accelerate I get excessive white smoke. Have dual exhaust... same amount of white smoke comes out of both sides... It also has a problem shifting from 2nd to 3rd and 3rd to 4th.... I shift the truck into neutral kill the engine, start it again, put the truck back in drive and it will shift correctly... I am fairly new to diesels. Any help would be greatly appreciated.

Thanks...

[Robyn]

First things first here

:D:D Welcome to the Diesel Page:D:D

Now
The white smoke is the result of a fueling problem, timing, Injector pump issues.

If this problem just popped up or even if it came on slowly you may have a plugged fuel filter.

The filter is almost always suspect as it is easy to check and replace.

Make sure you have a good supply of fuel to the IP at about 2-4 PSI with a good volume too.

If the supply (filter) are ok then there is the real possibility that the IP is taking a poop.

This engine has very little electronics on it and uses the DB2 injector pump. This is an all mechanical pump so if there are issues its farily easy to issolate.


Be sure of the fuel supply and pressure and let us know.

Now the 700R4 is a mechanically modulated tranny and has only a small amount of electronics envolved and that is just for the converter clutch.

Turning the engine off and back on should not really have any affect.

What exactly is the issue on the shifts?? Slipping, slow, late, harsh ?????

More info please

Let us know

Robyn

[BionicTiki]

I though about my post on the drive into work this morning and I will admit it's not very detailed...

I bought about 2 months ago...I knew it had some problems... Replaced the FuelTank and Sending Unit because the tank was shot... I just changed the Injector lines and Injectors because two of the lines were leaking... All Injector lines are dry as a bone on the outside (no leaks) I took an ohm meter to all glow plugs and at running temp all glow plugs read between 6.2 and 6.4 ohms. I only get white smoke when I take off.. AKA 1st gear and a little in second. I will change the fuel filter. I didn't think it needed changing because the previous owner had date stamped it 09/07. I will replace it ASAP. I will let you know if it helps...

Transmission... 1st gear rev very high before shifting into 2nd, then 2nd will never shift into 3rd just rev high... Its on and off too. Last night I drove it around town, it shifted correctly about 20% of the time. The turning the engine off and back on again works every time... If I am having the no shift problem, stop then shift into park or neutral, the truck will not shift into reverse... but if I turn the engine off, then start it again it shifts fine...
I read some posts that said to check the vacuum pump and lines so I replaced all the vacuum lines and the pump... there is a bank of 3 electronic switches/devices that all the vacuum lines tie into on the driver side of the engine(Red, Green & White...What are they??) . I sprayed them down with electrical contact cleaner and plugged the wires back in...

Let me know if you need any more information...


Thanks for your help....

[DmaxMaverick]

Definitely sounds like it's starving for fuel, or air is getting into the system. When this happens, the injector timing gets advanced (mechanical throttle input), with no more fuel. With air, it retards the timing, also causing white smoke, as unburnt fuel is pump out the exhaust.

Most common possibilities:

Fuel filter, as Robyn said. This should ALWAYS be the first thing to replace anytime you have any fuel/running issue. More often than not, it's the problem.

Fuel lift pump. When they fail, the engine will run, but only run well and have low RPM power under load, like accelerating from a stop and shifting through the gears. Gear shift points will usually be delayed, because the power output is much less than anticipated according to the tranny setup and throttle position.

Air leak, between the tank and fuel lift pump (a leak between the lift pump and IP would be an external fuel leak). Could be anything in the circuit, including a poor clamp/connection, cracked/corroded line, fuel sender unit, cracked/damaged hose, and the lift pump itself (the braised inlet fitting can become "unbraised" or crack).

Fuel line restriction. Could be a kinked/bent metal fuel line, or a pinched or under-radius bend (kinked) on a hose. Could also be a poor hose/barb connection. Sometimes the hose "delaminates" as it is inserted, and the inner part of the hose plugs the barb (invisible from the outside).

Check your fuel pressure at the filter outlet or where it enters the IP. You should have 4-7 PSI at idle, and any positive pressure at WOT under load.

[Robyn]

Tranny could have a throttle pressure cable issue and or any one of a number of issues.

The best thing to do is to get a pressure gauge on the main pressure tap and see whats up.

The 700 is controlled by the governor and it could have issues.

The first thing I would do is drop the tranny apn and see if there is a load of crud in the pan.

Filter could be partially or mostly plugged.

Check out the pressure and then see whats in the pan.

The 3 solenoids on the VC are the EPR, EGR and the lockup control

The 700 is a mechanical and hydraulic controlled unit so it cant be scanned to see whats up.

Let us know

Robyn