Identify my (apparently common, but not publically solved) idi smoke problem

I've got an 86 6.9 - bought it after it sat a few months, this truck was possibly known to have an intermittant smoke problem. When I initially got it started it ran okay a few days, but it's been about 6 months and generally gotten worse. I've tried to blow it out on the highway a few times, no change. It's gone a few times, so the engine clearly has the mechanical capacity to run well, even if it's not perfect. When running right it's idled rock solid, not smoked under any throttle position, etc.

But, normally, it stumbles and misses badly, puffs intermittantly more and less white smoke, blows a constant cone of white smoke, fogs up my half of town, etc.

I pulled the injectors a few weeks ago, and about an hour after turning it off, found the whole drivers bank wet and foamy on the tip - replaced all 8 with new delphi injectors and a return cap/line kit, but had no change.

It's a tempramental issue - it hasen't run right in months, but even as it changes, you can tell that it's the same problem, with the same character. At higher RPM it gets a "heavy" feel and really blasts smoke, there's some speeds where you can hold it on the edge of not running right, and it wants to go, but you can feel some cylinders are either being flooded, or not timed right, or something. It's the kind of feel that makes you want to really romp on it and blow whatever's in it out, but it never does blow out, just blows fuel in...

Just pulled a valve cover, it's got spots of sludge spatter on it, but it's soft stuff, all valves tight...

So, do I need an injection pump?

*edit* I also dropped the tanks a while back - I had thought that turning it to the back tank seemed to be linked to it misbehaving, and found brown crud in my filter. They were nasty, but I cleaned them both, filled up, gave it a considerable overtreatment of lucas fuel stuff.... didn't make ant change. Now it's only got the front tank hooked up, to simplify things.

Well first thing I'd do is new filter full of ATF, run it for about a minute and shut it off and let it sit all night. The detergents in the ATF will work on the IP overnight and might help.

After that I'd get the timing checked. Mine was waaay off. Mine's still not set right because I don't have a meter but it's way way better than it was.

I'm CERTAINLY not a professional but it SOUNDS like retarded timing might be part of the problem.

Timing. 99% of the time, when you've got smoke and low power, missing etc... it's timing. I haven't found a single IDI that didn't need timing adjusted; usually on the retarded side.

Stickies say pump time and timing.

Clb said:

Stickies say pump time and timing.

Click to expand...

What I've really been wanting is something confirmed "[resolved]", or the like....

As to the timing, perhaps I'm misunderstanding, isn't static timing just a matter of lining up the marks on the gear?

I can't imagine I won't need a pump, based on my other mechanical experiences and how it's running - I just want to be really sure, it's a big one to swallow - it looks like a good reman is about twice what I paid for the truck.

Also, funds and location dictate that it's not being looked at by anyone but me.

*edit* multi-post

Hit the stickies
Look for timing threads, members in your locale have meters.
100 k is life span on ip and sticks

Idi tech section first.
Second hall of shame
Third search your issues to get a primer.
Its been hashed out here I garontee' it.

Clb said:

Hit the stickies
Look for timing threads, members in your locale have meters.
100 k is life span on ip and sticks

Idi tech section first.
Second hall of shame
Third search your issues to get a primer.
Its been hashed out here I garontee' it.

Click to expand...

Texas is a big place.... I kinda doubt it.

Done lots of searching, but people have a tendency to not report back - in fact, they seem to lean towards giving up on the truck or motor.

mechanicalmoron said:

Texas is a big place.... I kinda doubt it.

Done lots of searching, but people have a tendency to not report back - in fact, they seem to lean towards giving up on the truck or motor.

Click to expand...

I've noticed there's a lot of people that don't have a clue about these old IDIs. There's a guy locally who seems to be well respected and does a lot of work for a major canned foods supplier (Libby's if you're curious). I asked him if he had the equipment to time these and he started talking about pulling it apart and lining things up then adjusting the valves to fire at the right time. He also told me these motors are pretty much junk after 100k which obviously has been disproven many times on here.

My point is, if you find a good shop they can get it fixed, but the shops that know these motors are getting pretty scarce these days.

I am gunna bump the timing thread for you guys.
Ps
If someone has the tools to do the timing right, and has the ability ALSO they will know right off the bat when asked.

Ok Texas....
Bumped the timing service registry for ya..
Cruz thru and look for someone in your parts

I have a shop in ****** ... Ferret adapter and light. There most weekends and some weekdays...welcome to use them, if I'm not too far away from you
I'd recommend the "ATF trick" prior to timing adjustment.
Just my two cents.

mechanicalmoron said:

Texas is a big place.... I kinda doubt it.

Done lots of searching, but people have a tendency to not report back - in fact, they seem to lean towards giving up on the truck or motor.

Click to expand...

Where in this little old state are you? There are places, several close to me.

Also, as much as 'proper' timing tools can do a better job(at least with new IPs - not convinced on worn ones), you can do just fine with some test-and-adjust/by-ear timing.
It won't be number-perfect, but it's not hard to get just about anything running 'well enough', getting good power and mileage... Because the optimal timing for power(aka engine fighting itself less) is generally good for fuel economy too.

Macrobb said:

Also, as much as 'proper' timing tools can do a better job(at least with new IPs - not convinced on worn ones), you can do just fine with some test-and-adjust/by-ear timing.
It won't be number-perfect, but it's not hard to get just about anything running 'well enough', getting good power and mileage... Because the optimal timing for power(aka engine fighting itself less) is generally good for fuel economy too.

Click to expand...

With all due respect, right is right. Everything else is wrong in my opinion.

Kizer said:

With all due respect, right is right. Everything else is wrong in my opinion.

Click to expand...

Well, I disagree for a few reasons:

1. What is right? Even if you have the 'correct' ferret tool, there is plenty of discussion about what number to use. I've seen 6 degrees and 8 degrees, perhaps higher or lower.
Turbo owners tend to run lower numbers than NA owners, which makes sense to me.

2. What do you do when things aren't perfect? A new IP will do one thing, as the IP wears, the timing will change.
More importantly, the timing /curve/ will change. Unless you intend to just replace your IP as soon as it starts wearing(and, lets face it, $500+ for a new IP is a big investment in a truck that can be gotten for under $2K), you may have to 'work around' some of the quirks, at least until you can get the money for new parts.

3. Pulse/ferret timing meters give you a number when the fuel is injected, not when it's actually burned. Differences in fuel(especially obvious between Europe and the US) will change how fast the fuel burns, which may well change the 'optimal' timing point. There may also be differences even within the US.

4. Temperature changes will affect how fast the fuel burns too - so an engine with lower compression may need more advance than one with high compression.
Also, adding boost will increase the combustion temperatures... But only at higher RPMs where you have that boost.

With all of those factors, what is 'right'?