I'm wondering if the lack of black smoke is the key to my whole problem. It seems to me that if I had one bad injector that I still should be able to produce smoke at the exhaust by going WOT pulling the 8K trailer. I've been trying without success. In a properly running truck, should some smoke be easily visible going WOT from 0-55 for example?


I have the symptoms:

1) Unable to get more that 14 PSI of boost. I think this may be reduced to 12 or so under some conditions
2) High EGTs
2a) When pulling a 6-8% grade max speed of 35MPG and RPMs need to be kept down to about 2250 to keep EGTs below 1250
2b) Even with small hills higher RPMs seem to raise EGTs. (better to be in OD at 1800 RPM vs 3rd at 2500)
3) Passenger side EGTs seem to be higher than driver side by as much as 70 deg or so under load, less at cruise.
4) Black fuel filter - only the outer filter seems to have any black on it.
5) Inability to produce smoke at WOT under any conditions


Here's an effort to address each of the above arguing that the issue is a lack of fuel:


1) Can't get enough fuel to the engine to get it to "want" more air - so can't get max boost.

2) As load increases the engine is getting all the air it wants but not enough fuel. This causes a lean condition and raises the EGTS as well. This is why both side EGTS raise quickly.

3) We don't have a baseline with the truck running well. It could just be the probe placement or some issue with the data capture. It could also be that we have a lack of fuel AND an injector issue....

4) There is not a significant loss of oil, maybe the black fuel filter is from junk (isn't there a rubber pickup foot in there?) in the fuel tank and is related to a fuel blockage.

5) Due to fuel delivery issue, we can never get to a condition where there is more fuel than air delivered to the engine so we never get an excessive fuel vs air condition and therefore no smoke.

The one issue with this seems to be that when starting from a dead stop, I would think that even with a fuel delivery issue I should be able to produce some black smoke.

What do you guys think?

 

I guess something like this would not show up in PERDEL data?

 

This is what happened to me on a steep grade:

Going up a grade in 3rd gear. The truck seems to have the umph to continue on, but EGTs are rising and hit 1250 and are trying to reach higher. I take my foot out of it and am forced to 2nd gear. In 2nd gear, I have to keep RPMS below about 2250 or so. If I mash the peddle I can get to 2500 or more RPMs but the rise in EGTs prevent that. So I keep in the 2000-2250 range with EGTS in the 1100 degree area and crawl up the hill.

 

If you have a perfectly matched set of injectors, a proper Hutch mod, and the right CPS, you might see a PERDEL of something like 2 on the offending cylinder, but I suspect we're talking a partial fail. The difference may be barely perceptible at idle (maybe a pup-pup-pup at idle and white smoke with a winter start) - idle is when PERDELs are measured.

Now... install the lead mod on the foot and the heavier throttle will show a real difference. This is one of the buggers of diesels: You can have a partial miss or an imbalanced injector, where gassers are more "digital" - a yes or no on firing at all because of spark.

I'm facing this same problem right now, yet I don't know if I lost a stick, compression in a cylinder, or my mind. I'm hoping a breakout-box will tell me which VC to pop and where to focus.

 

1250 EGT's on both manifolds or just the one side?

 

Passenger side comes up first. The driver side isn't far behind. Here's a previously posted chart tweaked to show EGTs a little better. The X Axis is minutes.

 

What type gauge & probe are you using to monitor EGT's?

 

PLX Devices EGT Module.

 

Where is the temp probe located?

 

 

Not a fuel pressure issue. ~63 PSI at idle/cruise and ~55 PSI WOT. Top port on the fuel bowl.

Here's a question. After shutting down, how fast should the pressure bleed off. It goes from 60 to 10 psi really fast maybe 5-10 seconds. Then from 10 PSI to zero or nearly zero over the next 10 or 20 seconds.

 

Here's a video KOEO. The beeping is the key going on, pressure rises. Then I assume the pump is shut off. The pressure drops, fast. The key was on the whole time.

 

The fuel pressure at KOEO looks normal. What kinda seems a little concerning is the drop off at WOT with a stock setup. Even though it is within an acceptable operating range I don't recall seeing a fuel pressure drop on a stock setting.

 

For some reason I thought they were supposed to hold pressure. Here's a video (turn down volume before playing) of a 30-50 mph WOT run. The best I could get in the dark....

 

I still wonder if the previous owner had a performance tune loaded on the PCM.