I have the quad race box. On any setting, I'll romp on it and come to a stop light a few seconds later and idle. My truck will idle at normal rpm fine, but will shake and feel like it is going to die. When the box is off it does not do this. I have had this truck to 2 different dealers to check for anything and of course unless there is a cel the mechanics cannot find a thing wrong. Any suggestions. I have no kitty, donaldson 42" muffler and free flow air intake as well. Fuel filter has been replaced about 2000 miles ago, I have 5000 miles now.

 

I think you answered your own question......

 

How so, Dodgezilla?

Jasco, I've observed that the idle rail pressure sometimes drops very low with the Quad Race on PL1 - but only after prolonged/repeated use of WOT.
Doesn't seem to affect idle quality or RPM, though.

 

xlr8r, interesting. I do not have the rail pressure setup yet on my commander, so I don't know about pressure dropping or not. I guess there could be something wrong with my fuel system somewhere. Does the quad box use enough fuel to need an aux fuel pump? I have noticed that after a cold start the truck starts and immediately kind of backfires like fuel has puddled somewhere. The dealers say they cannot find anything without a cel. How would a fella make an small leak bigger? Run the heck out of it?

 

Before my fuel mods, I would pull down fuel pressure to ZERO with just Quads XZT. I'd say yes you need some help..

 

You pulled your LP fuel pressure to zero on the Quad? Which setting? What did it run stock?

 

I have seen a few different trucks that had some anomolies with injectors. Not that they were bad but, it was like they would go out to lunch from time to time.

You might try an additive or something to see if they are carboned up at all or if you have a sticky injector it might smooth it out?

I have also seen some weak lift pumps that after a hard run have a hard time returning the proper pressure back to the injectors. Most of the newer style in tank pumps are much better but, some just have unusually low pressure right out of the box and then when you tax it with a module it cannot keep up.

The last thing I can think of is that your FCA might be acting up. For some reason these seem to be the weak link on the cp3.

 

XZT box... no settings.... I think I had one of those marginal at best stock pumps that quad is talking about...

That's long been taken care of...