I posted this and emailed to Allen Nelson yesterday afternoon. Still no answer yet, but thought some of the guru's here might be able to help.

Of course all mods in sig. I am running the FAL #292 efans and 160 degree stat. Anyways, two weekends ago, driving thru town, noticed my truck getting hot, had a/c on and all. Temp eventually got up to like 230-240, got it into open roads on way back to house and temps dropped. Once back home, noticed the fans aren't working. So get out the FAL directions and start going thru check list, I've got the updated fuse block. Wire was loose from negative battery cable wire. Re-wire and connect all this stuff and its working fine. No problems with fans since. While I was at it went ahead and dropped the efan on temp to work with the 160 stat, it was never done before. This is the first summer season that I have run the efans on this truck, but had some on my 2000 trans am when I had it. Anyways, fast forward to now. At idle with my cam under normal conditions, it idle's about 650 rpm. It has idled like this with the a/c on or off since the last time nelson tuned it. But since the efan ordeal, when the a/c comes on and the fans are running it idles up to like 850 or so. At stop lights and signs the engine just races, I'm sure that every one thinks I'm trying to race them. In traffic, its hard to slow down without using the brakes, can't just let it idle to slow down. I know that with the summer here the engine is running hotter and that there are 2 speeds on the efans and that they are running at 100% capacity more often now, but is this normal? Should it be causing the idle speed to increase that much. I mean it used to increase a little when the a/c and the fans came on, but it was only like 35-50 rpm. Could something have reset the PCM when the wiring came loose on the fans or what?

I know I had installed exhaust cutouts on the truck the same morning that the e-fans went out on me, but I can't see that causing any problems pertaining to this. Sorry for my rant but I am all out of ideas here.

 

Does this only happen with your cutouts open or does it matter? I installed a single cutout on my truck recently and the other day while in traffic is started idling very low. It went down under 500 rpm and I thought it was going to stall. Maybe something related with Oxygen sensors? I capped the cutout and no more problems. Just a thought.

 

Well, to tell the truth, I haven't really thought about that. How close are you cutouts to the 02's? Mine cutouts are all the way back on the exhaust. I have the mufflers and dumps right at the rear axle, and the xpipe about 6" in front of the mufflers and then the cutouts right in front of the x-pipe. I doubt thats the problem, but I will check it out. I'm pretty sure its with the tune though, cause it doesn't idle that way all the time, just when the fans turn on full power or with the fans/A/C on. Something with the extra voltage being drawn, causes the idle to raise way up and race.

 

My cutout is right under the extend cab seating location. It should be far enough back to not cause problems. I don't really think they are causing your issue though.

 

I am almost certain that you have an issue with your idle air flow settings & throttle decay, I had a similar problem tuning this last cam I had, some paitence & logging should fix it

 

sounds like you have two different issues. got to agree with crazycutter on the air flow and decay for the hanging/racing idle. the AC issue sounds normal. there are four idle settings, one for in park/no ac, one for in park/with ac, one for in gear/no ac, and one for in gear/with ac.

 

idle air flow-idle air vs ect

values should graduate down as ect goes up, I would adjust that first

 

Well, I played with it last night, not the tune but the truck itself. I went and did adjust the efans cuton temperature, cause they were set way too low. I had messed with this when I was trouble shooting them not coming on. And then I also took Storm5.3's advice and checked all wiring and plugs and wires. Looks like I may have had plug wire #8 a little loose. When I pressed onto it at the plug itself, it just ever-so-slightly moved and popped into, like it wasn't sitting on the plug just right. So, far so go, I haven't had any issues with it idling high yet. And I let it idle last night for about a hour, with the a/c on and off and in drive and park. And it didn't do it at all this morning coming into work. So, the issue may have been solved. I knew it was running fine prior to this happening. Allen Nelson had tuned out all the Idle issues on this cam a coupla months ago nad ran fine for a while until this. Lets hope this took care of it.

 

Yeah, I don't know why these trucks do it but it took me 2-3 days to figure that one out when it happened to me. On mine it also changed the shift like it was stuck in Tow/Haul mode. I had a guy at a shop put it on his Mac scantool and it only showed an occasional missfire, no SES light or codes, just high idle and shift patterns. My brother found the problem after I had gone over all the plug wires. The no. 2 plug wire at the coil found its way loose, after that the truck ran fine. I had just changed plugs and wires about a week before this happened. So hopefully you can use this info one day to troubleshoot yours if it should happen...Zed

 

Well, I will say that I had my doubts about the plugs/wires causing the issue, but seems that may have been it. I had the idle and shifting issues, and had thought yesterday on the drive home that I may have heard an occasional miss.

Never threw codes though. Maybe this thread will help others in the future.