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Smoking IDI

9K views 15 replies 4 participants last post by  Michael_V8 
#1 ·
Hey. Got a 94 e350 with the 7.3 idi. How long do the stanadyne db2 pump last? It smokes quite a bit and has a bad exhaust smell. Im replacing everythin necessery on this van to make it run as good as it can. So the pump has 140 000 miles on it now and has never been rebuilt. New injectors at 120 000 miles.So whats the life expectancy on these pumps? Im going to turbocharge it with the hypermax pulse kit, soo was considering the moose junior pump, or any other suggestions?
 
#2 ·
What does the smoke look and/or smell like? Sulfer smell usually means that it is burning oil. If it is fuel, I would look to the injectors possibly leaking as opposed to the IP having trouble. Does it smoke at idle, or does it only smoke under load? The life of the IP depends on how well it was cared for. Meaning clean fuel, the proper fuel, things of that nature. I have seen injector pumps last for more than 300,000 miles, then I've seen them last less than 50,000 miles. It really just depends on how they are treated.
 
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#3 · (Edited)
A few years ago I was in the Stanadyne authorized injection shop and I mentioned I also had 140,000 miles on my pump since it had been rebuilt and asked how long they will go (using only clean diesel fuel). The answer was, "They'll go a hell of a lot longer than that". I agree, we had loaders, trucks, and other diesel equipment where I worked and most would go decades and never have the pumps in need of a rebuild. Just looked in my maintenance log and I've got 173,800 since the rebuild in '95 and my pump performs like when I bought the truck new in '91. There's keyboard mechanics on other sites that say pumps/injectors only last 100,000 miles, their commercial diesel experience----zero.
 
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#4 ·
Its smoking at idle when cold(which my previous idi also did) but still smokes a bit grey when its warm, cant see it in the mirrors but when parked i can see a bright grey/blue smoke and it smells bad,my wife gets sick of it. its not using any oil as i can see. Change it every 5000 miles. Maybe i dont use it often enough, only about those 5000 miles a year. Its car nr4 and only used as a holiday car and some weekends, but since my father bought it new and i really want to take care of it i want it to run as clean and good as it can, so i really want to find out whats the cause.Im a bricklayer and no mechanic but these engines are quite easy to work on but need some advice from ppl who have more experience than me. Do you think injectors can go bad after only 20 000 miles? I hear that the diesel in norway is dry, what do you think of adding 2 stroke oil in the fuel? Could it help to turn fuel pump up a bit as i allso going to turbocharge it?
 
#5 ·
When you turbocharge it you will have to turn it up a little. What does the smoke smell like? Oil, or partilly burned fuel? It could be that the metering valve is getting a little worn, but it has been my experience that worn or sticking injector nozzels will cause the excessive idle smoke, because the fuel isn't atomised correctly. When starting there is usually a little puff of smoke, sometimes while idling cold there will be some smoke. Usually not after warmed up. A little oil (transmission fluid, Marvel mystery oil, 2 stroke oil sea foam) won't hurt anything, but it probably won't help much either. I woudn't put it in the tank, I woud prime the fuel filter with it, then let it sit over night after starting and running for a few minutes.
 
#6 ·
smells more of unburned/partilly burned fuel.No oil smell..yea might be incjetors, took it to my mechanic who is working alot on Mercedes Benz diesels and he thought so as well but i was a little sceptical since they recently are changed..I have 2 old rusted out vans with the hypermax kit innstalled so might as well just swap dieselpumps from one of these part cars first and see how that turns out, if it still smokes then i buy new injectors
 
#7 ·
The IP timing on these 7.3 engines is very critical, a bit of retard will cause the white smoke. When replacing injectors the IP should be re-timed, if it's know what the pop pressure is on the replacement injectors, should be 1850 PSI + or - 50 PSI, you can start at 8.5 to 9.5 BTDC and go from there to see what the performance is, smoke and power.

If you don't have a reliable timing unit like a Ferret and a programmable timing light or a Kent- Moore unit, you can set the timing on a cold engine so it cackles a little until the hi idle solenoid de-energizes and it comes down to 650-700 RPM and smooths out with no cackle.
 
#8 ·
I have never had the timing equipment. I pull the IP with the lines still attached, and all of the clamps in place. Then I hook the lines up on the replacement pump, that won't let the pump go in any way but where it was originally timed. Not very scientific, but it works for a poor boy. I've never had any timing troubles when I did it this way. Let me add that it is sometimes a trick to get all of that mess(pump and lines) out and back in, but it can be done, and it has worked every time I've done it.
 
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#9 ·
Or if you're removing then reinstalling the same pump just make index marks on the pump housing and gear housing. I had my original pump rebuilt so my original factory marks are what I used and to this day that's where the pump sits, lined up as when I bought the truck new in '91. And you CAN replace injectors without affecting the timing.
 
#10 ·
And you CAN replace injectors without affecting the timing.
That would be like the OEM just threw a set of injectors in an engine and ship it out without actually timing it.
If you install a new/remaned set, and never check the timing, you have no idea of where the most efficiency of that engine is. On a 6.9L/7.3L truck there is a timing quartz transducer on #1 cylinder, on a Van, it's on #4 cylinder, that is used by the factory to time the engine to there designed 8.5* BTDC fuel injection with injectors set at 1850 PSI + or - 50 PSI.

In 1982 I was GF of maintenance at the LEP, we did run the 6.9L on of our three Dyno for many tests including WOT destruction. The 8.5* BTDC was found to be the ultimate production setting, some engines had a little higher Dyno output at 9* BTDC .

But I guess my recommendations are mote.
 
#11 ·
No you are absolutely right. I was just giving a way to do the same thing and achieve the desired outcome without having all of the necessary, and I might add expensive equipment to time it and know exactly where everything is. Like I said my methods aren't very scientific, but they work every time they're tried. Replacing the injectors and timing the engine is something simmilar to replacing spark plugs on a gas engine and timing the engine. All of the books advise it, but it is rarely done. I might also add that since I never move the clamps, I have never had an injector line break. That doesn't mean one of them won't break tomarrow, but one hasn't broken in the 25 years that I've owned a diesel powered vehicle.
 
#12 ·
Wasn't saying timing shouldn't be correctly set. Point is, just replacing injectors which pop off at only 1800-1900PSI triggered by an IP that's putting out 20,000 PSI (that's why IP lines are steel) isn't going to affect pump timing. Matter of fact, there's quite a few diesels out there and the only way to change the injection timing is tear the front of the engine down and replace a gear.
 
#13 ·
#14 ·
Thanks for the input :) Just fired up the donor car 3 days ago, had been standing for 3 months. Had some white smoke for 2-3 minutes and then nothing. So there is deffenatly room for great improvement on mine. When you say that timing is ''good'' at 8.5 to 9 BTDC, is that the marks where the pump should be? Will it in time move back or what causes it to smoke or move over time? sorry for my stupid questions but im totally blank on this..
 
#15 ·
Do you know anything of the history of the engine. For instance has it been run on straight vegetable oil, or used crankcase oil? Because of the much heavier viscocity, using oils as fuel can cause some pretty bad things to happen to the injector pump, which would be indicated by the symptoms you describe. Mot to mention there really is no way to remove all of the particles from crankcase oil. It doesn't seem to hurt the engine much, but it can riun a good injector pump. Vegetable oil can be done, but it is a lot of work, and involves using some pretty harsh chemicals. Crankcase oils should never be done.
 
#16 ·
My father bought it new and had it for 10 years, i found it online 2 years ago and bougth it back straith away. The years in between i dont know so much about other than that it has had an oil change once a year at a shop, but diesel isnt that very expensive over here and the car has only 225 000 KM. But i might just send it to a diesel specialist if i cant make it rund good with either pumps, when im finished with the turbo swap and exhaust so i can get it running like it is suppost to do for a long time.
 
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