Well, a new twist. My 86 doesn't really smoke except JUST when you let off the throttle. Then it blows a good puff of white smoke. When you have your foot in it, or when you're running steady speed, only the faintest smoke trail is occaisionally visible.

Soon as you either lift your foot or start downhill it starts blowing some smoke. When you completely let off the pedal it blows one big puff then stops. When you're kind of coasting downhill, but don't really let off the throttle, it leaves a fairly good trail of smoke.

It also idles pretty rough when its warmed up - sometimes. Sometimes it idles fine. It idles even worse until it warms up pretty consistently. It kind of lopes faster then slower then faster then slower - the repeat frequency is about once a second.

So is this an injector problem, a CDR problem, an air intrusion problem, or some combination of all 3?

 

My guess would be stuck oil control rings if engine sat around not being used and had minimal oil changes by the PO, or valve guides are worn and or valve guide seals are ineffective, hard or just plane gone.

 

Ya' know, I kinda was thinking of those possibilities too.
But, based on my experience with gassers...

1) worn or stuck oil rings usually smoke pretty consistently all the time - and this one isn't
2) valve guides/seals will usually smoke a bunch at startup, and also when you take off after sitting and idling - and it isn't doing that either
3) niether of those things would make it idle so inconsistently

I may be wrong, but at this point I'm not thinking its the rings OR the valve guides/seals....

Anybody got other theories?

 

Sticky injector, Short them out when it's idling rough and you should find it.

 

Yeah, that's kinda' what I was thinking.

I cracked all the lines the other day and every one of them made a significant difference in the idle so I figured they were all OK. BUT it was idling well at the time. Guess its time to pull out the 5/8" end wrench again.

Wonder if maybe a speck of dirt might have got down in one of them and caused it to hang open? I can have 'em bench tested and cleaned for about $5 apiece. Maybe I'll just have to have that done.....

 

Jepper mine does the same thing but i know its alittle of all cause after 300000 miles i'd be worn also but if i'm going to take the ime to pull inj out then i will replace also way to cheep to put back in jmop

 

Well, yes and no. I can replace them with remans for $15-$20 apiece (only 3-4 times the cost). BUT, from what I've read, installing new injectors with an old pump is a recipe for ending up with a failing pump - and vice versa (a new pump will cause failure of old injectors).

Everything I'm reading around here leads me to the conclusion that the pump and all injectors should be replaced at the same time as a set. Since I have a spare motor, I figured I'd have all 8 of those injectors bench tested and cleaned, and if any were bad, I can then have ones from my motor tested and cleaned a couple at a time until I end up with a full set of 8 clean, confirmed, good ones.

 

I had the same problem, it was the pump.

advance it a little bit, if it fixes it, know your on borrowed time, but otherwise enjoy the ride.

 

Gee, um, thanks for the words of encouragement

Seriously though, I'm hoping Spectramac's diagnosis is correct - but knowing my luck it probably will turn out to be the pump

 

id have to say your pump is going out......

 

I'm not sure where these guys are getting their diagnosis. Bad pumps smoke blue people!

 

My 92 WAS doing the same plus plenty at morning start up.

after reading ALOT on it, I tryed the suggestion of useing Diesel Kleen
and it has (knock wood) cured both of my problems, and I have experimented with different ratios and if I use 8 oz. to 12.5 gallons (or better) then I don't get any smoke.

my .02

 

Bad pumps smoke blue people

ok explain that to me. All the db2's I've seen die have all smoked white on letting off the throttle, and idled rough.
db2's are pretty common in farm machinery, our forklift has one, the tractor has one, generator has one, my trucks have them....

anyway, you're the posting guru, so Cheeper, listen to Spectramatic.

 

Now don't get all offended and snappish there DeepRoots. Everyone is entitled to throw out an idea for the possible cause - and its OK to give the reasons why you think your diagnosis is the correct one. Even if it requires stating why you think someone else's diagnosis isn't correct. We all learn that way.

Three things to keep in mind (once you know them)....

1) Posting Guru isn't just a title - Spectramac has earned it by being around here for 3 years and posting (on average) about twice per day
2) Spectramac works on these things for a living (or at least did at one time), and lastly
3) He has already helped me TREMENDOUSLY by correctly diagnosing my pump as being 180 degrees out of time - when the general consensus from everyone else was that it must be dying. Read through this thread to see what I mean - especially pages 3 & 4
https://www.ford-trucks.com/forums/5...olution-3.html?

So, no offence intended, but I will "listen to Spectramac" and at least try his suggestion first. The great thing is that if it turns out NOT to be an injector, what have I lost? A few minutes to test them all? I can always proceed with the other suggestions if that isn't it.

Thanks AGAIN guys....

 

Maybe our definition of white smoke is different. Every bad pump I've seen (and I've seen many) blows big clouds of light blue smoke. Hey, I could be wrong. I've replaced a lot more pumps than injectors to tell you the truth. Just saying you'll feel pretty bad if you replace the pump and it still does it.