it all depends on whats wrong with the pump to what color smoke it blows internal lt blue to grey blue advanc grey to white but the smell always gives it away unburt fuel stong enough to make your eyes burn but i agree with ya both seen many in my days of schooling

 

Just trying to go in order guys. If a truck rolls in the shop with a problem like this, your not just gonna tear into it and replace the pump. You need to do a little checking things out first. Now if Cheeper comes back and says, "I got it to miss and can't pin it down to one cylinder", then the next phase kicks in. Then we can all try our best to harmonize, "It's the pummmmp!"

 

Exactly. You've obvioulsy got me figured out already, Malcom.

Try the easy, cheap diagnostic things first (especially the free ones), then work your way up to the more difficult and expensive possible causes. I never start with throwing expensive parts at a problem in hopes of fixing it...

BTW, my smoke is pretty white - or at least seemed so to me. I cleaned the CDR too - 'cause with the air cleaner off I could see a trail of liquid oil inside the intake plenum from the CDR orafice. That may be at least a little of the smoke.

Next I'll try cracking the injectors one by one and see what happens - stay tuned....

 

I am more less having these symptoms with my 1994 F250 7.3 IDI 200k miles (pump and injectors are original )- . I removde the injectors and took them to a local diesel shop who tested them and found 3/4 of them bad . I bought a new set of Delphi LJC01101 injecors from them and now it smokes worse with lots of smoke when you back off the thottle . It puzzles me that I have more smoke now ! I guess I need a pump too ?? What do you guys think about the pumps from the Ebay sell Dieselcare ( www.dieselcare.net in Memphis TN) ?

 

Yes, more smoke is strange. New injectors should atomize the fuel better and burn cleaner. Here's the question... what color smoke?

 

Blue-white . Maybe unburned fuel ? Would a bad pump with new injectors make it like this ?

 

There you go dwaymar, that's the kind of thing I'm talking about, and why I don't plan on jumping right into new injectors with my old pump.

Did the new injectors make his pump go - or was the pump already gone and part of the original problem? I don't know - but I don't want to take the risk myself.....

 

Usually the pump has a lot shorter life than the injectors. We've actually only changed a few sets of injectors at our shop over the years. I guess it's possible the new injectors could be putting a higher load on the old pump and make the bad flex ring run further out of time. I think the pump would've already been bad though.

What happens if you snap the throttle and let off?

 

Puff of smoke.
"What happens if you snap the throttle and let off?"

 

now the big ? is are the injecters set up for the pump some shops say that they are all the same injecters but the injecters have a code this code will tell you how much fuel this pump can handle but if 200 on it then change both at sametime but also have new ones tested if getting them from shop sometimes even a new one is not up to snuff

 

jeepers i thought you got a new pump from napa ?

 

I did, but when I figured out (with Spectramac's help) that my real problem was that the pump was 180 degrees out of time, it ran so much better that I returned the Napa pump. A bad pump wasn't my problem - being 180 degrees out of time was.

I cracked the injector lines today. The second one from the front on the driver's side seems a bit weak. Cracking the line on it didn't make as much difference as the other 7 did. So its looking like that may be the problem - correctly diagnosed by Spectramac again

Another question for the Gurus. Will being timed too slow cause one to blow some smoke? If so, will it contribute to the "big puff of smoke when you let off the throttle" type issue I'm dealing with?

The reason I ask is that while I was messing around with it today, I started changing the timing a little. As I adjusted it slower the smoking got worse - especially the big puff when letting off it. So I started adjusting it a little faster. The smoking seemed to get significantly better - and without the clattering getting any worse. I'm beginning to think I've had the timing retarded WAY too far ever since I rotated the pump 180 degrees. I'm just not used to clattery the sound of a diesel.

I'm just going to have to take it to a good shop and have it dynamically timed. Once I know that the timing is right then I can start tracking down any other remaining issues...

 

Here's another one of my Ooop's. When I first got my truck I didn't do to much to it. It seemed to run good and didn't smoke much. I finally decided to check my timing after a few years. It was running at 0! I ran it up to 8 and what a difference! I kept having to let off the gas to keep from speeding everywhere.

 

Well, I got to REALLY take it for a drive today for the first time. Over 200 miles round trip. I'd never driven it more than 30 miles at one stretch before....

It is still puffin', and still doesn't seem to have as much uuumph as I'd like to see. I got to determine the EXACT conditions that cause it to puff smoke. Driving along 65 or 70 mph (2000-2500 RPMs), pedal halfway to the floor no smoke. Snap off the throttle and it will put out a BIG puff followed by a short trail of smoke - then it just stops smoking again. If you start down a grade or just let up a little it will start trailing some smoke and just keep trailing smoke until you put your foot back in it.

At low speeds it won't do it at all now. Anything under around 1800 RPM you can snap off the throttle, ease off it, or whatever and no smoke. Above 2000 RPMs though, snap off it, ease off it, or even start to coast, and it smokes. The smoke all smells strongly of diesel - a smell I'm starting to get pretty used to at this point.

I swung over to my buddy's house this morning and pulled the injectors off the spare motor. Gonna' get 'em bench tested and cleaned and start swapping them out until I get 8 good ones in it and see if I can get the idle to smooth out and if it will stop smoking.

I'm unsure if I should take it and get the timing set dynamically BEFORE I start swapping injectors - or should I wait until I know I have 8 properly functioning injectors in it first? Opinions?

BTW, Spectramac, when your timing was slow, did your smoke at all? Still wondering if the timing has anything to do with it.

 

Like Spectramac, I drove my truck around for a year and half dumb fat and happy, with a bit of smoke, and underpowered. Finally broke down and put in rebuilt injectors and pump. Cold advance on it rattles like a bugger, as soon as it warms a bit, advance off it has a classic diesel quack (NOT rattle) and goes like stink-(might be the headers), but honestly, if you aren't happy with performance, just bite the bullet and put in some known good fuel system components, I wished I had done mine right off the bat, since it saved me a couple of miles per gallon to boot.