The truck is a 2003 305/555 engine. Stock except for a quazilla xzillaraider box set on the fuel economy mode.

The truck is a manual and at a light it wants to idle at 1000rpm (which is normal cold idle) even when it's 60F outside and the engine is at operating temp. If I hold the brake and let the clutch out slightly to load the engine, it returns to it's normal 750rpm idle.

I thought maybe it was the throttle pedal sensor or temp sensor so I got my code reader and plugged it in to look at the sensors in real time and the throttle sensor and temp sensor stay at solid values so I'm not sure what the deal is.

Anyone have any ideas?

Thanks,
schu

 

whats the temperature on the motor?

if its a little above the 205-210 mark, id venture to say your fan clutch, further stressing my point, if you see a P0483, id venture to say you might have found your culprit..

 

You could try an new FCA, but my bet is you have an injector leaking. How many miles on the originals?

 

Engine temp is 195ish. The code reader doesn't show anything odd or spiking so I don't think it's that.

Interestingly enough, I removed my quadzilla xzillerator II and I haven't had it happen since. So perhaps my quad box is bad.

Leaking injector is a possibility. Truck has 125k miles. It's had the quad box on for most of that, though I keep it in fuel economy mode, and even when it's not, I don't pour the coal to it.

How much is a set of injectors and were do I get those? Are they difficult to replace? I consider myself a decent wrench, just not up on the cummins so much.

schu