... and I can now read my fuel pressures. I am having a problem with the truck hesitating and what feels like a quick pulsing in the fueling, or something do that extent. I thought that maybe my fuel filter was clogged (it is new) or the LP was going out, but the Commander reads 6psi at idle at the CP3, and rail pressures look good. Anyone know what the symptoms of a leaking or cracked injector are? It doesn't look like anything else is out of wack. Oh, and this happens with the Quad Race OFF, but is slightly more pronounced when it is on. I don't notice it much while under acceleration, but when cruising it is noticable.

Any clues?

 

Nice having Fuel and Rail pressure handy, huh!

Sorry I do not have more to add. Maybe try some injector cleaner or an additive. It seems those things clear a lot of little injector complaints up.

Quad

 

This sounds exactly like what i was feeling when i had the XZT. I couldnt figure it out. After a couple weeks, maybe, it just plain went away and never did it again. It was most pronounced cruising up a hill. When i gave it more throttle, it went away.

 

I run PS Diesel Kleen and MMO in every tank, so I don't think an additive will help. Now that I think about it though, this whole thing started about a month or so ago when I was towing my Jeep up to PA. I was driving normally with my old Juice on lvl 2 and I heard a quick snap, the truck "hiccuped" and then the CEL came on. Turned off the box and it didn't do it again. Turned it back on a couple hundred miles later and it did it again. This happened several times over the next week, and I sent the Edge in for an update but sold it and got the Quad Race box. Now even with the box off I have this hesitation / pulsing. I'm wondering if I messed something up while towing? Quite annoying either way. I'm really hoping this problem doesn't effect my towing of my Jeep on Friday (the first time since this crap started). If I get stranded I'm gonna be mad.

 

Ok, lets start at the top.

Is it light or heavy throttle?
Steady throttle or when you are accelerating?
IF it is doing this and you add throttle does it go away?
How about if you let off the throttle?
Does this happen at any particular boost level?
Does you boost gauge fluctuate when this happens?
What rpm's does this happen at?

That should get us started.


Quad

 

Is it light or heavy throttle? Seems to be much more noticable under light throttle, but is still there at heavier throttle.

Steady throttle or when you are accelerating? Again, much more noticable at STEADY throttle. If I'm getting on it I don't notice it as much.

IF it is doing this and you add throttle does it go away? I can't really tell if it goes away, but it is much less pronounced.

How about if you let off the throttle? Hard to tell if this helps. I'll make it a point to try again tomorrow.

Does this happen at any particular boost level? I haven't noticed but I'll check this again tomorrow as well.

Does you boost gauge fluctuate when this happens? I'm pretty sure it does not fluctuate.

What rpm's does this happen at? My normal cruising RPM while going to work is around the 1800rpm range, but it is noticable throughout the range of 1000rpm through 2500rpm (about the highest I shift at unless I'm getting on it).

I'll check these things in detail tomorrow and note anything I can tell. I think I'm also going to back my tone ring off to stock position just to make sure I take that out of the equation.

 

Check and clean your intake air temp sensor. The truck might be trying to compensate on a rationality problem between the MAP and the IAT sensor.

I see you have the BHAF so this should not be the issue, but I have seen oiled filters cause a problem of sorts.

Basically the truck is fueling and running based on the MAP sensor. Then it checks the IAT sensor which is also a pressure sensor of sorts. If there is a reading that starts to be different than what it is calibrated for the truck will try and compensate and it will feel real funny when you are driving. It feels like it wants to go and then stops itself and then tries to pick up. Not as bad as pressing the accel pedal on and off, but enough to notice.

If it gets dirty enough the engine can and will act funny at idle as well.
Obviously when you are accelerating pretty hard there is enough airflow and pressure changes that nothing is trying to stay in an exact range. When you are cruising at 60mph the truck does stupid stuff.

Just something else to check. I guess I could just blame it on the Juice, but that would not be too fair would it!

Quad

 

You know, that might be something for me to check. When I first installed the BHAF I just had the IAT zip-tied to the outside of the filter. A while ago (maybe 4-5 weeks) I decided to drill a hole in the intake pipe and install the IAT in the stream of air. Maybe I messed something up? I'm going to recheck everything there, and maybe even return that sensor to it's old zip-tied location just to check things out. It makes sense if that sensor got mucked, it could cause problems at cruising speeds, but not when the turbo is really sucking in the air.

 

Let us know if it works.


Quad