trying to learn about diesels as I go. Thought that doing a head swap on a 85 6.2l would be a great way to learn. Boy was I over my head. I know absolutely nothing about diesels and am not ashamed to admit it. THis is the best diesel site I have found for replys to inquiries so here goes.

Swapped heads out, put new ones on. Followed all torque proceedures and specs. Did everything right out of the book. Went to crank it over, would not start. Started to do research and learned about air in lines. Thought I would have to do all the thing necessary to bleed air out, this is all strange to me as I am used to gasoline engines where this is not an issue. Well, also learned about the importance of cranking RPM, and the starter was not even trying to roll over at a speed necessary for these baby's to roll over. SOOOOOOOOOOOOO. replaced the starter. Weighed 10 times what a gas motor starter does, wow. Well thought MAYBE just MAYBE this bbaby would get enough jujice now to roll it. Well it scared the hell out of me what a good starter sounds like compared to the old one. Still would not start AND run though. Wanted to roll and kick but not run. So called it a day and came back 2 days later. Glow plugs cycled......... bam. The thing fired. Then died. WEnt again at her. bam fired but had to floor the accelerator to keep it going. And OMG the smoke. I have never seen anythning smoke like this thing. I mean actually made me run out of the garage hacking the amount of smoke that was coming out of this pig. As soon as I let off the gas, it died. Thank god. I would have died in there. I never dreamed that anything could puke smoke like that. So figured, hey changed the heads due to moisture, maybe water in the exhaust in the cylinders, in the pan. I do not know. Fired it up agaqin. Let her run <FOOT time whole the gas on>and ran like 5 minujtes. Let off it dies. And the smoke.......... thought they would call the fire Dept. Honestly. AMazing. I had to laugh regardless of the frustration. BUT, that is my problem in a nutshell. Am lost and ready to send it to the bottom of one of our Minnesota lakes. Any help would be great guys. THANKS

Holy Cow, sorry, I'm working on a response but I need a second to laugh...
I had a similair experience, swapped a set of heads in a parking lot actually in my old 6.2 blazer...never do that again. Smoked just like you described, I took it for a brief test drive, why I have no reason, but it ran so poorly I couldn't outrun the smoke!
That was a few years ago, but to the best of my memory all I did was advance the pump timing a hair and drive it and it cleared right up. Did you have to loosen the pump mounting bolts for any reason? All the compression washers under the injectors are in place? I think it also could be something to do with the hydraulic lifters. When all the tension is off them for a long period of time they drain all the oil out and take a while to start working properly, and until they do, its like driving a big truck with a valve set way out of whack. Thats what I was told anyhow.

Now bear with me I am a rookie. But by mounting nuts you mean the three nuts on the firewall side of the timing chain housing? THat take a 15 mm socket, and a wrench. Hmmmmmmmmmm, yep took em all off. Though I could get the pump off that way. I was wrong!!!!!!!!!. now what????????????

Thats probably your problem then. The injection pump mount is made so that you can 'tilt' the pump either to pass side or driver's side to adjust your timing. Look to see if there is a mark on the mounting flange of the pump right where the top mounting nut goes. There should also be a coordinating mark on the timing cover. In a perfect world, they would be line to line and everybody would be happy. But because a 6.2 is a chain driven engine, the pump must be advanced to compensate for slack in the chain. If you find both marks, you want to set it with the injection pump turned about a lines width toward the DRIVERS side, which will make it slightly advanced, this is a good place to start and you should be able to operate the truck OK with it timed like this, if you have difficulty still you can advance it some more, but don't get too carried away. Make sure all three bolts get tightened back down, if they're loose, then the pump will 'fall' to full retard position and run like you describe, good luck!

oh you are a god!!!!!!!!, will try that for certain tomorrow. If that works I will be the happiest man on earth. What if I cannot find the marks? Do I this with the enigine off? Can I fine tune it while running? That would cause this thing to billow smoke rings like the indian signals? To the point of no recognition of the back of my garage?

Do not for any reason try and set the timing on a 6.2/6.5 with the engine running. IF you rotate the pump with the engine running the sudden movements of the orientation between the injection pump drive gear and the head inside the injection pump can cause the head to bind. If the head binds, you'll get to see a spinning injection pump momentarily with loose mounting bolts, hopefully you don't get caught up in it (I've seen pictures).

There should be a scribe mark on the timing cover that continues accross the mounting flange of the injection pump. All 6.2's have the timing marks (late model California emissions models have a circle to align).

thanks a million guys, will try this after work today and post my findings this evening. Thanks again, hope this is all it is.

Do the timing as the others have suggested. Then take her for a spin and get some heat built up. Many times after R&Ring the heads there is oil or solvent present that will smoke until some fire gets built to clear it out. What color is your smoke? Usually timing related smoke will be grey or blue. Keep in mind that 6.2's with bad injection pumps will start to slowly loose performace over time, fuel mileage will also suffer and smoking will increase due to worn internals. Get her running a little better and then we will see where you are.:grd:

all of you guys are gods. The injection timing was absolutley what was wrong with it. I timed it a hair past the line tp the driver's side, fired it up, and pow the thing ran and idled. Few more questions for you guys though. Help me if you can. A: Turn the truck to on, glow plugs cycle, turn key and truck starts, release the key the truck runs but the glow plugs cylcle again. any ideas?B: the truck still smokes some at idle and under a load. Am I advised to run it for a week or so then fidle with the timing again? Adjust it now? possible there is just stuff in the exhaust-intake-heads? Just did the head swap. Let me know guys. Again you guys are awesome. !

The glow plug controller (in the left rear head) will cycle the glow plugs back on momentarily on a cold engine at start up. I hope you have the Delco 60G glow plugs. You mentioned head swap. Were the old ones bad and are the new ones good. You mentioned that you were inexperienced so I wonder a little about your heads. A good 6.2 shop will check the heads out for cracks and do the proper mods.

I replaced the glow plugs with new ones. just went to our local Checker auto parts and bought replacemnet ac delco plugs. Did not know there was a difference. WE had the heads cleanen a fluxed at a head repair shop and they say they are good heads off of a Suburban. Do not worry about the glow plugs then? Even after the engine starts? The smoking?

Don't worry about the glow cycle. You will get the initial 8-10 second glow cycle, then after you start the engine you will see the "afterglow" which will be up to 3 short cycles lasting about 2 seconds.

As for the smoke, you will see smoke under a load, it's a diesel, and a non turbo diesel at that. When under a load you will see smoke. At idle you shoudn't get much smoke once the engine is up to full operating temperature. If you do get smoke at idle, it will be cold but the smoke will be white (the kind that burns your eyes).

Hope this helps! Enjoy your Diesel!

As always with a diesel, the color of the smoke is important, black = over fuel, blue could be timing related or other injection problem. These engines are OIL burners and sometimes when something is wrong on the injection side, the engine will actually use the oil on the cylinder walls for combustion which will result it blue smoke and oil consumption. White smoke is usually unburnt fuel on a cold start, could be somewhat blueish. The blue smoke that is questionable is when you see it under a load.:exactly:

If your smoking at idle, it must be white smoke, and I assume your getting whitish smoke at all RPMs. Advance timing another line's width, verify that you have good fuel supply pressure and we'll go from there. I'm assuming since this is an old 6.2 that had cracked heads, that the engine has quite a few miles on it. If the injectors haven't been done in the last 100k miles, they're due. If advancing the timing a little more doesn't fix it, then you could be looking at injection pump trouble or a really worn out timing chain. Start the truck and pull the oil filler cap and have a listen, if it sounds like a chainsaw, you need a timing chain, that will correct your injection pump's base timing and cam timing.

ok, new scoop. Going to try to advance the timing a little more. Still lopes a little at idle, and smoke that burns your eyes. New issue though, in the morning the thing starts right up. LEft it running to get warm and then my friend's wife shut it off. When he tried to restart it the starter would not turn over. Very slow to turn over, then nothing at all. Charging issue, or the starter getting hot? Is there a cable that goes straight from the alternator to the battery? Before I got the truck the previouse owner redid all of the wiring between the batteries, to the starter, and to the alternator and glow plugs. So I am going on all the wiring off of theories and ideas on gas motors. No diagrams to go off of.

Start with the simple things first. Clean all the battery conections and grounds. Check to make sure alt. belt is tight. Get it started and check charging voltage at the batteries, should be above 13.5v. Check battery cable connection at the starter. Every thing needs to be clean and tight. The double battery cable connection on the right battery is a big source of corosion. Take the spacer apart and clean well. Let us know if this helps.:grd:

Batteries and cables are all new. Corrosion free. Have a side-top in the passenger side- the main one. The top post I have going to the 2nd battery and the second batter grounded to the air conditioner bracket. The side mount on the main one I have going to the starter and such below. I have a wire running from the positive-top mount to the alternator. Is this correct? I am lost, went home at lunch at jump started it and it fired right up so it has to be a charging issue.

new status, checked the voltage at the battery- 11.5 volts. Removed the alternator, brought it to Checker and had it tested. FAIL! Purchased new alternator- installed, 13.5 volts at the battery. So now we are back to the smoke issue. I am going to try to advance the timing just a hair and see where that puts me. If I can get that right, THEN I AM DONE!!!!!!!!!!!!!!!

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