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Issues With White Smoke

D

dirtwork

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Chardon OH
I have been having a ton of white smoke issues after startup on my 92 6.5. I just got the truck so after a little investigating decided it was time for new injectors (looked to be original at 181k) and the glows were the original 9g's. The truck would start up easy, but white smoke (eye burning unburnt fuel smell) and rough running and miss until it would warm up, anywhere from 1 to 3 minutes, or more, depending on ambient air temperature. I got the new injectors, and 8 new Duraterms installed yesterday. When we fired it up the first time it started remarkably easy (within 5 seconds) and only a puff of smoke. Ran relatively smooth with some spit and sputter but after 15 minutes of idle time was smoothed out just fine. Shut it down and let it cool down. Went to start later on and we have smoke again. Not nearly as bad as before the work was done but still not right. Clatter is a little louder than before too, which I would expect some with new injectors. Its kinda acting like air, but no leaks, good LP operation. I have only driven it about 2 miles, so not sure if it just needs 'run" a little. Strange that it was fine the first startup after the new parts and not now. Once its warmed up really good it runs great- both before and after, but throttle seems crisper now. If its shut down and started up warm or hot fires ups with a bump of the key. I tried to disconnect the ECT sensor but it seemed worse. Almost seems like it runs better when the cold advance is on. Truck is not rusty underneath and lines all look good.


Thoughts?
 
Couple things to visit, make sure your GP relay is functional first, verify voltage Under Load to all 8 GP plugs.

During wait to start (GP cycle) you are supposd to give the acc pedal a push to set the high idle solenoid.

Check for continuity on the high idle/ cold advance switch, cold engine. Located on the T-stat xover. Should be a Closed circuit below around 100 degrees.

Check base timing at IP, mark on IP should lean slightly to the driver side compared to the mark in the timing cover.. (advanced a little)

Drain off water from the T-valve and bleed air from the thumbwheel on the FFM.
 
Good advice to check the cold start system.

The Duraterms (and worse 60G's) take longer to heat up than the 9G's. Light them side by side in a vise and you will see what I mean... You can also look down an injector hole and see how hot they don't get with factory glow times. Regardless, you need to extend the glow plug time. I use an aftermarket controller from Orileys that screws up and allows a full glow cycle after turning the key off and back on. The factory unit doesn't. You could build an glow plug override switch with a ford starter solenoid.

My next thought is a worn head and rotor in the IP. My 1993 never starts as good as my 1995. However I am throwing another IP at the 1993 now. I can get it to start but it will cool down and start to miss unless I put a load on the engine. It has hot start issues now. It did start good a long time ago before some really bad fuel.
 
Ok Updates so far. Went ahead and checked fuel filter, and swapped in a fresh one to be safe. Lift pump seems to be working fine, bled everything though t-handle and then some to see if engine would sputter with it open. Good there. Hooked up fuel pressure gauge and its good. High idle/ cold advance works. Glow plugs seem ok, will have to do more testing later when it cools off again. Fired it up, and same routine, but I took notice that at initial startup you get a good puff, then that goes away, where the issue seems to arise is when it kicks down the real hazing begins. Took it out and ran it and as expected it clears up. Checked the timing marks at they are basically lined up. I disconnected the ECT sensor and using a jumped the advance switch, even warm when I do that the engine seems to run better, more even clatter at idle. Maybe timing is the issue. Also zero smoke from the oil fill or dipstick tube warm or cold.

Timing Marks 92.jpeg
 
Ummmm... 281K on the timing chain? I would give it at least a quarter thickness of advance.
 
Michaeljp86 said:
Is that something I should look into? would that cause it to overheat?
Click to expand...

Timing chains are guitar string tight when new. After about 30K miles they have 1/2" or so of slop. They stretch a lot when new. Advancing the timing too much will cause excessive diesel rattle. You can time these by ear. Even a dime width advance on a new chain runs well.

Ideal advance is black smoke with the cold advance on and heavy throttle and the smoke goes away when the cold advance goes off. (Not factory or emissions, ideal power.)

Overheating is caused by other things - not like a gas engine where timing causes overheating.

No, I wouldn't bother changing the chain with that high of miles as you likely will need an overhaul including head gaskets sooner rather than later. Change the chain then after seeing if you have mains cracks.
 
I fired the truck up cold again this morning. When the advance kicked down, I unplugged the ECT connector and jumped the terminals to cycle the advance back on. Smoke and idle smooth right out. Unplug, and back to haze and a little miss until warmed up all the way. I assume of I advance the pump a little that "should" not only clear this up but also give me a little more advance when the cold advance is on thus helping the initial cold start also?

Where and how does the 92-93 get signal for glow plug time? ECT sensor? Or other?
 
WarWagon said:
Timing chains are guitar string tight when new. After about 30K miles they have 1/2" or so of slop. They stretch a lot when new. Advancing the timing too much will cause excessive diesel rattle. You can time these by ear. Even a dime width advance on a new chain runs well.

Ideal advance is black smoke with the cold advance on and heavy throttle and the smoke goes away when the cold advance goes off. (Not factory or emissions, ideal power.)

Overheating is caused by other things - not like a gas engine where timing causes overheating.

No, I wouldn't bother changing the chain with that high of miles as you likely will need an overhaul including head gaskets sooner rather than later. Change the chain then after seeing if you have mains cracks.
Click to expand...

The GMC I have runs really smooth, the chevy has a real hard diesel clatter. The chevy also pulls like a tractor. Som Im wondering if the GMC needs to be adjusted since its pushing 300k
 
dirtwork said:
... I assume of I advance the pump a little that "should" not only clear this up but also give me a little more advance when the cold advance is on thus helping the initial cold start also?

Where and how does the 92-93 get signal for glow plug time? ECT sensor? Or other?
Click to expand...

More advance will clear the white smoke.

The Glow plug sensor(s) are built into the controller. You can add a 10 watt 10 ohm resistor to the voltage feedback wire going from the glow plugs to the glow plug controller to increase glow time. (Off the top of my head so don't quote me on resistor values.) The controller uses a resistor to heat up a thermistor of course the resistor is powered off the glow plug side of the relay.
 
Michaeljp86 said:
The GMC I have runs really smooth, the chevy has a real hard diesel clatter. The chevy also pulls like a tractor. Som Im wondering if the GMC needs to be adjusted since its pushing 300k
Click to expand...

I would almost change the chain at 300K. Yes, adjust the timing till it sounds the same or have a diesel shop adjust the timing with antique tools.
 
I advanced the timing moving the pump about .030 to the driver's side. It appears to have cleared up the hazing after the cold advance kicks off. Timing marks are now offset slightly as they were basically lined up before.

ECT sensor may be somewhat out of spec, as I think that the advance should stay on a minute or two longer than what it is, as I don't believe its staying on until the coolant temp reaches 120, seems to cut out a little soon. I plan to replace the ECT sensor as peace of mind.

The truck still puts out a decent puff at initial cold start and runs a little rough until a couple after glow cycles, and I also am leaning towards the initial glow cycle not being long enough. I may try a new glow plug controller see if it helps or if not good PM anyhow.
 
It is called a cold start switch. Supposed to click open at 140 degrees. Dealer item I recall. ECT this truck doesn't have, only a sensor for the gauge.

If timing solved the problem I would leave that fragile crossover alone. Otherwise be very careful changing it out.
 
As per the TTS tech. ref. thread, GM# 10154649 for the above mentioned switch.

I ebay'd mine.

Rock Auto has them for 34 bucks. Copy paste # into the part # search function there.
 
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