Ok guys, know some of you have some ideas here. I posted up about this last week or so, but still having the same issue. This all happened after the e-fans crapped out on me and engine started getting hot. Got the fans working again and they work fine now, I did raise the temp that they cut on at, not much though.

But the high idle is still happening. Once the truck gets hot, the idle raises way up. Like way up to 850-900 rpm. It usually idles about 635-650 rpm. I thought I had it fixed but then again this morning got in some badass traffic on 45 south, the engine temp started goin up, I cut the a/c on to help drop the temps, and the idle shot up. Temps started lowering, but the idle continued. I notice this too mostly when the a/c is on. But once I cut the a/c off it stays/stayed up high, until I got out into some open road. The bad thing is that when its like this, the engine races and then stays in gear longer and surges and I can especially in low rpms like 1st-2nd let off the gas and the speed will stay the same or even sometimes increase. Its almost like the Throttle body is sticking open or something. I don't know if it has to do with the tune or what. It wasn't doing this at all before the problem with the efans. I have talked to Allen Nelson and he checked my last tune and there was nothing there that was wrong unless something could have changed since then which he thinks is unlikely. I cleaned my Throttle Body this past Friday, I have a new one getting ported right now anyways. I have checked every spark plug and plug wire. Now I do have a plug wire that the very end of the plug boot has been against the header and burnt a little bit off of it. Its not showing any wire or anything, but think this could be the problem? I also thought that maybe it could be the MAF. I descreened it a long while back, but maybe its taking a dump on me? I also, changed out to a 160 thermostat when I did the cam install. Since this seems to be related to the A/C, electric fans maybe the stat is faulty. I really have no idea. I have check and disconnected and reconnected and cleaned every wire and connection and visually checked everything that I can think of here.

Any suggestions would be great.

 

Im coming back into town sunday if you want to try a new maf I have my stock one if it will work for your truck. Sorry to hear about the problems man but I dont have a clue you have done everything that I would. The spark plug wire seems like it should be fine too. It just so happens that i have a set of msd plug wires that I havent put on yet and we could try putting one of those on the "bad" one and see if that helps too.

 

Yeah, I've actually got the stock wires that came on the truck, I think I'm gonna go home tonight and try that one just to see. I really don't think thats it, but maybe.

 

you know, i get the same thing on occasion with mine, i think its something to do in the tuning. dosent bother me that much, i have mine idleing at 715 though, it usually shoots up to 850 according to the hpt scanner.

 

No expert but have you tryed spraying starting fluid around intake to throttle body just to make sure throttle body gasket is still sealing and might as well spray all over just to make sure you have no leaks .double check cruise cable adj & throttle cable routing.

 

look at idle rpm vs ect and idle airflow vs ect

 

Do the 04's still have the IAC or does the computer crack the throttle blade a little bit? (I'm assuming 04=drive by wire)

 

Ding Ding - we have a winner! Sounds like a vac. leak to me.

 

Yeah, 04=Drive By Wire. No cable adjustments to play with. I will try spraying starter fluid around the intake to check for leaks. I tried my extra plug wire, replacing the one that had been touching the header. No change so I'm narrowing it down. Any other areas to check that a vacuum leak could come from on these motors?

 

Hey guys, I know there are some of you that had been trying to help me out with this and I appreciate it.

Think that Allen and I have found the source of the problem anyways, although its kinda weird and I really don't understand how it could affect the idle. Anyways, Allen suggested that I try to run the truck up to operating temp without the use of the fans and see if it happens, basically disconnecting power from the Flex-a-lite VSC thinking that it could be causing electrical malfunctions. You know the VSC has never had any problems right?

Anyways, so I did this on the way home last night from work and got it up to the temp where this would normally occur, had the vsc unplugged pulled into the home depot parking lot for my experiment and low and behold, no high idle, even with the A/C on, the idle was slightly higher because of the a/c running, which is normal, but not the 850-900 rpm idle that had been occuring. Plus I let it sit there for quite a while and it never duplicated it, so I know it would have been hot enough to do it. The a/c was blowing hot air. Then just for giggles, I plugged the vsc back in and after it 4-6 second startup period, bam the engine RPM shot way up. Strange but true. I don't really understand it, but I really hope that the VSC is the problem, because thats an easy fix.

I just need to get with Allen for one of his fan harnesses. I will keep posted on this and let ya'll know the outcome of this.