Good. I'm glad you found the leak. But in your short vid you say "Gerry you're a f*ckin' genius."

I know you already called me a genius in an earlier post, but c'mon, who told you the problem was likely a vacuum leak and suggested a smoke test?

C'mon. Just sayin' ...

 

HAHAHAHAHAHAHHAHAHA! Geniuses for different reasons. You, because you identified the issue, and Gerry for a simple setup to perform the diagnosis. That better?

I’m glad I don’t have to spend my diagnostic time monkeying with this silliness and can get back on task of resolving all the other stuff.

 

OK, I’m gonna revive this as I’m seeing more stuff.

So recapping the issue, it looks like I’m having a vacuum leak. As I’m working doing strong diagnosis- and I should have mentioned this previously- a little smoke came out of the brake booster line. The red “ring” isn’t there (it is on the parts truck and actually works well) so I couldn’t pull it and inspect, but in lieu of getting the new part in for that, I did the RTV redneck fix around it and going to see if that helps.

I’m also going to do the PCV mod as the hose clamp is not at the plenum side and it don’t think it’s been replaced- but may have.

Getting more to my point, this is what the Nanocom came up with for rough running:



Am I correct in thinking this is the passenger bank? Could the PCV be the source of this? I didn’t see any smoke come out of that orifice, but I dunno.

There are no misfires on that screen. I still get P0734 and P0171 sometimes, but not all that consistently. I’ve reset adaptive values in the fuel system and the transmission.

Of note, it is not showing a speed? Could this be the source of my P0501? Or at least a clue? I know I’m jumping around, but it’s all starting to come together a bit.



Also, anyone know how to change from C to F for temp readings?

 

GOT IT!!! I did the PCV mod and that must have been the last leak. No CEL, no codes, perfect idle, and the roughness per the Nanocom is all gone and zero misfires. No P0171 or P0734 either.

WOOHOO!!!!

Man I love this forum. It has help so much and made have one of these things so much fun.

 

Since you replaced the MAF, I think you ought to re-set your adaptive values (you might have already). Very easy to do with Nanocom.

 

Yep, sure did. Values in the fuel trim and O2 sensors screens on the UG are in good shape now too. The screen on the Nanocom with that one bank having rough idle has now been eliminated too.

I did get the code for the purge valve for the SAI (P0441) and I’d previously put in the one from the parts truck but it came back. I suspect I have other SAI issues to track down because it doesn’t come on when I start it all the time, but I might get one of the alternate purge valves and see if that does it. I also need to replace the throttle body heater plate as it’s leaking a bit I think. I’m going to replace the intake filter in the SAI at some point too, but by and large, I think I sorted the issue I had.

 

So I drove the Disco to work this morning and started monitoring my fuel trim and O2 sensor value pages on the UG. The O2 values are really pretty good and after doing some decent research on those I learned a good bit.

For the benefit of the collective, and since this thread is technically about values of that nature, I learned that for the O2 sensors, .45v is more or less 14 to 1 and a perfect mixture. Above that and you are rich and below it is leaning out. Mine really are hovering around .45 and pre and post cat values are pretty close too.

However, back on fuel trims, the short term is pegging at 25. The truck is running just fine and the economy is more or less the same as it always has been. My only codes are P0501 (the VSS one that I’ve had since purchase and I think totally unrelated) and P0441 for thre SAI purge valve.

I just reset the adaptations in the Nanocom but have about 100 miles since then and I think more than 4 drive cycles, so I would have thought that would have cleaned up. My long term trims are still at zero, but I’m concerned I still have an issue.

Any ideas?

 

I forgot to mention on this tank I put in a couple cans of sea foam and a few months ago did a can into the intake to clean things out as a matter of course.

Think I need to clean the injectors? Could the heater plate and/or the purge valve be contributing?

 

Just to keep adding info here hopefully to help someone out at some point:

I’m replacing the throttle body heater plate and it’s going great, but a couple things I noticed that make me raise an eyebrow:

- the throttle body itself was barely over finger tight. I know it shouldn’t be horked on, but that just plain borders loose

- when I pulled one of the vacuum lines off the purge control valve, I got a bit hiss from one of them. This probably explains the P0441

Both of these I bet are contributing to the fuel trims being so high. I’ll order the valve and obviously mildly tighten the TB to the intake.

 

No way to change it mate. We are stuck with °C on our Nanocoms. Just as we can’t change the Instrument mileage or BCU mileage from km to miles.