I've been using Shell Vpower (93 octane) since I bought the truck.

Since my last post I've taken off the TB and cleaned it very well. (wasn't too dirty) I also reset the computer as recommended. Still no change.

One thing that I found very odd though, This morning sitting at a red light.. studdering along, I bumped the steering wheel and the rpm's went back to about 700... Finding this rather odd, I wiggled the steering wheel about an inch back and forth.. and the RPM's kept rising. I could probably redline the truck doing this if I moved the wheel fast enough. I tested this in drive as well as park, and found the same results. Could this be connected to my studdering issue


Edit-

Just found this site http://www.dsm.org/how-tos/tttt/tttt3.html - Its exactly what my truck is doing. Is it possible that I got a bad IAC when I replaced it? Before I installed the new one I hooked it up and turned the key to the on position. The little **** in the middle barley moved... maybe 1/8 of an inch and turned a little.. Exactly like this video -
http://www.youtube.com/watch?v=igVQcAq-40M

The old IAC I replaced moved exactly the same amount as the new one. Should I return the new one and try again? Also, does anyone know the part number for this from Autozone or Advance?? Could it be whatever controls the IAC?

 

Check incoming voltage to the TPS to ensure that it stays below 5 Volts while bumping the wheel.

Second if you read on how to properly clean a IAC it will tell you never to move the plunger in any way before install because it will break.........

 

Ill have to find my meter to check the voltage.

Also, I didn't touch the End of the IAC, I just plugged it in and turned the key to the on position to see if it moved any more than the old one.. (which was slightly like the one in the video I posted.)

I think Ill take the IAC back to autozone and try another another one.

 

Don't forget the position of that changes with temp sensor input{open or closed loop}=what was the temp of the motor when you measured it=cold would be more open or shorter in to allow more air in vs hot start which would be out more...how old is your temp sensor=maybe throw the engine into closed loop..No trouble codes is weird=how bout getting the comp reflashed at a dealership or using a realtime scanner=one that logs engine function during usage=carchips are alil on the high side but they work here's alink-I got mine for about 80bucks=shop around=beats chasin your tail and it works pretty good at findin probs

http://www.davisnet.com/drive/products/carchip.asp

 

When you say temp sensor are you referring to the small *** thing in the front of the car near the radiator? If so, I'm not sure. I only bought the truck a couple months ago. Oddly enough I did find that unscrewed from the front and tucked back in under the Air filter box.. I put it back on the front about a week ago.. No change yet.. Might as well replace it.. I've replaced so much so far that the guys at Advance know my truck without having to ask

Also, I've thought of having the comp flashed, would I be able to do that myself with a superchips programmer? Not sure which one would be cheaper.

another thing thought about was adjusting the small screw on the throttle arm (kinda acts as a landing platform) in order to hold the throttle open a little.. Maybe a turn or so just to even the idle out above 500rpms

I took the truck to Autozone yesterday and asked them to test the Battery under load... Unfortunately the guy that tested it didn't know how to test the battery under load... Guess I'll try a different Autozone on the way home.

 

Dragon<------ You got it backwards. More fuel when cold and more air when hot...... It works like a choke but other than that, you got it.


Jmodix<----- The temp sensor he is reffering to is the Air Charge Tem. Sensor The one in front of the radiator is a temp. sensor for the over head display. On a 5.9L and 5.2L it is located on the front ,passenger side, middle, on the intake manifold. This could be your problem.

 

doesn' t the I.A.C. system in cold loop lean or enrich the fuel mixture by air amount inlet=not injector fuel pulse?......and the real time scanner does work from davis

 

Air amount inlet restriction therefore fuel enriched.


Again there is more fuel than air ratio needed when cold. Cold air is more dense=more mass and therefore on cold there must be more fuel.

Think about it, when you have a small engine you choke it to start it which pulls more fuel than air because the throttle plate comes across the intake port.

 

Well.. I give up. I could not find my Volt meter.. So I just went and swapped the IAC for a new one. I also replaced the Air charge temp sensor. Neither have helped the issue.


At this point I've put alot of time and money into fixing this, and I don't think im gonna throw more money at it. Had planned on an Exhaust system being added to it, but this cut a small whole in those plans.

I'll save up and get a superchips flasher and see if that helps, but that will be down the road a bit.


Thanks for all the suggestions.

 

could it be possible one of your injectors may be getting weak? not getting the good pressure release that may be causing the rough idle? Or maybe check the overall fuel pressure?