This has been going on since I bought the truck however now that it's getting a little colder it's more and more irritating. When I start my truck in the morning or if it's been sitting all day it has a really rough idle and the throttle sticks for about 3-4 seconds when i shift when I redid the plenum i replaced all of the sensors on my tb and used a voltmeter to check the one on the intake and it was fine, this always stops about 5 min or so after driving any help would be great. ( the 180 tstat, cai, duals, and kegger are really the only engine mods I have done so far.)

 

Check the injectors and see if they are a little clogged. As a routine maintenance I run injector cleaner through my tank every couple of months just to prevent this problem. It may be snake oil, I dunno, but so far so good.

 

well when I did the plenum i soaked them in gas for a couple days then flushed them several times, also it seems like the idle would always be bad not just the first 5 min or so

 

Since you already did all the sensors, then I would say either there is a PCM problem, or one of the new sensors is bad. That has me stumped. I'm sure the other guys will chime in soon enough and probably go in a totally different direction. BTW just to make sure, you did thoroughly clean out the TB didn't you? Also make sure all your linkage is set up properly.

 

I also soaked the tb but again seems like that would be a constant problem, also it is not throwing any codes as for tb linkage ill go take a pic

 

All that may be is your IAC. It may be shot. Replace it and it should be fine. The other thing that will also cause rough idle is a shot PCV and clogged breather and clogged injectors.

If your truck runs a little rough AND idles rough- your injectors need to be taken off and cleaned out. You can NOT clean them on the truck and NO additive will clean rust or debris out of the pintel and valve areas. All the additives do is break down varnish- that's it.

You will have to take them to a shop to have them cleaned properly. This can not be done on the bench at home. They need to be powered on and activated along with high pressure solvent run through to force out the valve area. That's why they need to be done at a shop.

IF you have been having this issue for a long time- it's either due to three things:

1. IAC has never been replaced and is shot

2. You have rusty fuel supply feed lines and rusty fuel rails. They should all be replaced with new ones.

3. You may have carbon build up on the bottom of the TB around the AIC air passage but, since you stated that you soaked it however, I don't know what you meant by soaked. Does that mean that it was removed from the truck or soaked while installed?

IF it was the latter, that's no good. You have to remove it, use a stiff bristle brush and clean it. First remove all the sensors and gasket. Clean it using Acetone, Carb Cleaner, Mineral Spirits, Denatured alcohol, Lacquer thinner, or brake cleaner to remove all carbon residue. Then, replace the IAC. Get a new gasket and that will take care of that part.

I am just going though this now in fact with the fuel rails. The OEM fuel rails are junk. They are cheap sheet steel that rusts and, once it starts, it needs to be replaced. The walls break down and what ends up happening is that the flakes of rust end up in your injectors. Same thing happens to the fuel supply line- the inside wall starts to flake off.

I just replaced my intake with a Hughes FI and all was super smooth at idle- so smooth I thought it died at a stop light. Then, two days later- it's back to running rough- just like it was PRIOR to changing the intake.

Pulled the fuel rails- LOADED with rust despite having flushed them out prior to the build. I would seriously check all those that I mentioned first as a start to resolving this issue.

 

I believe iac is on tb and all of those sensors were replaced and i soaked all the parts in a bucket of gas one night and in a parts cleaning tank the night before that didn't really see any rust in the fuel lines but I didn't look until after they soaked and I flushed them so I'll take them back apart, if that is the problem should I replace the rails and is there a good place to buy them?

 

heres some pics maybe someone will see something thats hooked up wrong

 

bump** really need some help with this

 

I don't think you have rust in the fuel rail. From the pics, it looks like you have the plastic fuel rail. IIRC, plastic wont rust.....