Jon, you are absolutely correct. Thanks for reminding me! Now that I think about it...it was last year about this time when I was looking at my EOT and trying to get it warm enough to run a CCT with my AE. I struggled to get it hot enough at idle.

Later that summer, my water pump finally started leaking a bit so I went ahead and changed it along with a new t-stat.

This winter, I noticed that my engine warms up MUCH faster than in previous years. In winters past, I had to drive or 12 or 16 miles before my gauge would even THINK about moving. In fact, I started using my block heater last winter just so I could have cab heat on my drive to work. I don't have to do that any more, I get heat pretty quickly now. I figured that my t-stat was stuck open and I was driving like that for who knows how long...

So, now that I think about it...my t-stat was probably stuck open last winter, which explains why my EOT was so cold at idle. I mean, it was like 165 while driving and then as soon as I parked it dropped like a rock.

So, thinking out loud here....if a relatively stock engine has it's t-stat stuck open...then the EOT would drop at idle in cold weather....the PCM would adjust the timing....etc, etc.

Could also explain the wet stacking issue that some experience when idling for long periods while others haven't had any issues...

Hmmm...

 

Yeah, it was around 40* when I watched the EOT's this year... I remember last year that if I let it idle for 10 to 15 minutes, it'd only take about 5 miles to burn myself up and that was below-freezing temperatures. This year, it was above freezing and it'd take about 20 minutes of driving after a 15-minute warm-up to even get anywhere near too warm. But yeah, my truck is warm now, has it's power back, and is quiet!

 

In my thinking, the PCM doesnt know the oil condition,

It's calculating timing on temperature and RPM's and the fuel table.

There must be a value that the engine MFG uses for an oil condition variable.

So the PCM is able to adjust based on oil temp, but not overall oil condition, as in type of oil, or how used it is.

So I think it's fair to say that a thinner oil would advance the timing while the PCM is making calculations based on whatever number the MFG uses for oil.

Now if you have a problem reading temperature into the PCM, I can imagine a very skewed number being used for timing, instead of what is intended.

This is just my out load thinking.

 

If any VO ends up in the motor oil - its a BAAAAAAAD thing in a hurry. This guy is using a Vegistroke system and therefore never runs VO until engine is at operating temp - theoretically long after any blow-by typical of a cold diesel has stopped.

VO in crankcase rapidly polymerizes. I've seen oil pans that looked like black cottage cheese - but that was extreme blow-by (dead cylinder) and extended oil change. But loooong before you could 'see' anything, these particles are bigger than what fit into the places oil is needed to do its job. I've met a number of VO/diesel 'blenders' over the years that STOPPED after getting a few UOA's back showing increasing wear pattern...

Can we say the star pattern is NOT indicative that there has been a 'problem' or 'abuse'? Is there some reason this guy shouldn't just rebuild the top-end and put this engine back in the van and hope for another 300k trouble-free miles??

 

I could be wrong...but I always thought the star pattern occurs because the fuel burns on top of the piston landing (crown or whatever it's called...) vs inside the bowl itself. Before I took my injectors apart, I always imagined the injectors sprayed fuel down into the cylinder but that isn't the case. The injector pattern sprays sideways out of the nozzles (or nearly sideways at least). This leads me to believe the piston should be pretty high up in the bore so the fuel is sprayed into the bowl area, below the landing (crown).

Am I close or way out in left field here?

 

There will still be a little vapour always getting in the oil.

The VO burns a lot slower than #2.

I had a waste oil truck way back.

If I did it again, I'd remove the intercooler so it's getting hot air while driving. I'd also have a air intake exhaust heat exchanger on a switch, so the air intake air is hot while idling too.

I believe this might fix wet stacking issues while running WVO, but at a sacrifice of peak HP. On the bright side, without an intercooler it should boost up a tad quicker.

 

Actually, I'm saying that the timing is advanced in stock tuning... even when the engine is fully warm. They do it for emissions purposes.

And yes, on a cold engine, timing is advanced even further to greatly reduce white smoke.

As for the star pattern.... in stock tuning it's most likely not going to be an issue. In order to make timing a real problem, you also need fuel to go with it. Too much fuel at the wrong time makes bad things happen very quickly. Since fueling is quite limited in stock tuning, these engines last a long time even with the timing advance.

In regards to your tuning comment, not all tuners eliminate the timing advance. Actually, quite a few advance timing slightly over stock tuning, and most leave the cold timing advance alone. I went the opposite direction with my tuning. I knocked down the cold advance, and I also pulled the timing back to run less timing than stock. The result from that is I can switch back and forth between my tune and stock tune... and stock is louder. You can hear advanced timing when it's present.

 

Correct, there is an injection delay table that works with oil temp.

 

You are dead on. And your picture is a good visual representation. Now although these injectors don't spray sideways, they do spray at an angle, and not straight down either.

Go with injectors that have larger nozzles, and they spray at a wider angle. Meaning timing has to be knocked back even further.

 

Yeah, I noticed that when I uploaded the photo...looks like about a 30 degree pitch down from horizontal, does that sound about right?

Your last comment is interesting. I never thought about larger nozzles having a wider pattern but that sure makes sense. So, would the reverse also be true? Do the early '99 120cc injectors have smaller nozzles then the later 140cc units or was there something different with the internals such as the intensifier piston?

 

Nozzles are the same. The differences are internal.

On edit: Sorry, forgot to answer the first part. The picture looks almost horizontal. But that just might be the photo more than anything else. I don't know what the actual spray angle is for the PSD injector, I think it's somewhere between 130-150 degrees. But I'm going off of really old memory here.

 

Nice pic Greg, thanks for sharing that.

 

I'm interested in hearing your reasoning for this move.
I'm very picky about pump timing when I work on the old mechanical pump VW's because there is a very fine line between too much and too little advance on those engines.
Not enough advance and you can't get over a hill, too much advance and the engine will sound like a rock tumbler.
I'll work with it until the dial indicator is dead on when setting pump timing.

 

Threads like this one is what started me down that path. That and a really hard look at the stock timing tables in the programming made me realize that it's emissions based. I did some studying a while back about general diesel theory regarding electronic fuel injection and emissions control, and found the general idea behind modern diesels is to advance timing a bit for reduced emissions. Then the stock timing tables started to make more sense to me.

When threads like this started popping up, I put 2 and 2 together. Rather than advancing timing a bit more over stock along with added fueling, I wanted to do the opposite and try pulling the timing back. What I noticed was the engine got quiet. I then compensated a bit by massaging the ICP to ramp up a bit quicker for better atomization and to use shorter injection pulsewidth to keep the smoke under control.

What I did was change the timing tables to more closely follow RPM's and ICP, rather than specifically address emissions only. It's modeled more like the older mechanical pump diesels. It got rid of that clatter noise from advanced SOC, and my engine runs much smoother with very little smoke. I didn't pull the timing back too far, because when I did, I found that the truck smoked more and felt sluggish. So I kept playing with the timing until I found a nice balance. It took only a tiny bit of trial and error, but once I understood what Ford was doing, it was actually insanely easy to rectify.

It's the exact same thing you've found with the mechanical pump diesels you work on. Too little timing, and you lose power. To much, and you can distinctly hear it. The key is to start with less timing, then slowly advance it until you just start to hear the SOC rattle, then pull it back again until it goes away. At that point, you're dead on.

The only thing I did notice on these trucks is that at very low RPM's (below 1500), and at low ICP, these trucks do need a bit more advance or they won't get out of their own way when taking off from a stop (it's even worse at high altitude). So on my truck, that's the only time you can hear a slight bit of noise. However, I can switch back and forth between stock tuning and my tune, and my tune is still slightly quieter, since I'm still running a tad bit less timing at that range. At higher RPM's, there's a much bigger difference in noise.

Anyone that runs a chip or programmer... ever notice how some higher HP tunes rattle more than some of the lower HP tunes? Often times, those tunes are running more advanced timing than stock. Pull the timing back, and the rattle goes away. Find the sweet spot, and there's no power difference, yet the engine can still run quieter.

 

Ever get a chance to throw the truck on a dyno, Curtis?