New (to me) 2003 HO, high idles with AC off?

[cbalthazor]

Hey Guys,

So I read the buyers guide a handful of times after checking out some really bad trucks, and finally found a nice 2003 CCSB 6Sp truck and picked it up. Engine is the 305/555 HO. Is a nice, tight truck, only issue which I'm guessing is minor is that the truck seems to go to high idle if the AC compressor is off.



If the AC is on, the truck will idle right at 800rpm. For example, it will high idle at 1100rpm with no AC engaged, and then if you hit the AC button, the RPMs pull down to the normal 800. If you turn the AC back off, and tap the throttle, it's idle right back up- but with no throttle input it will stay at 800.



Anyone ever seen this/know of what would cause this?



Only other thing that I'd like to do for now, as the transfer pump is in the tank, is figure out how to make a secondary pump assemble/piggyback using the Glacier Diesel parts, just because I will be taking the truck to remote areas and don't want to get stuck.



Thanks for all the help, this is a very informative place!

 

[cerberusiam]

Will the idle pull down when you start to engage the clutch? This was a glitch in the programming in the early trucks that thye would try to guess when the clutch was going to engage and add a little fuel. Most of the time it guessed wrong and usually stayed high idling whne you came to a stop with the clutch pedal in. A reflash might help, it might not. The problem disappered for the most part with the newer trucks so it is not mentioned much anymore.

If it is high idling any time the engine is started or soon after it starts, thats a different issue and may be related to the APPS or ????

 

[JJPage]

Congrats on the truck purchase!

Any fuel related upgrades you are considering, I would call Richard at Glacier Diesel Power for assistance. He is very helpful and willing to "coach" you through an install.

Jess