Don't know what to try next

[rico47635]

My son just got home. He's going to take the IAC out spray some cleaner in where it goes and make sure the thing is even working, and then tackle the module. Never done that sort of thing before. Is the module held in place with regular screws? Judging by the pictures on Advance Auto Parts' site, it looks like there are only two of them. I already told him that if he drops one of the screws into the distributor that he's buyin me a new one!! LOL!

 

[Swims350]

I think it's 2 bolt head screws and a plugin, also if he drops the screws he'd just loose the screws that's it. Mine didn't have a place for anything to drop in the dist or anything.

 

[rico47635]

Kewl. That's good to know. He's really bad about nuts, bolts, screws, and whatnot magically disappearing while he's working on stuff. That module is only $45. I hope that's all it is. I've spent enough on this truck to last me a good while. I'd like to get some trouble free driving time out of it so I can enjoy it. It's the first 4x4 I've had in many years. My Ford buds are all givin me a hard time about buying a Chevy I've had problems with. I don't mind the ribbing. You know how that Ford vs Chevy thing is. LOL!

 

[rico47635]

Ok. Progress. He just came in and said the IAC plunger did not move when he turned the key to the on position. That means it's not working, right?

 

[rico47635]

The module is out! Kewl beans. Ya know, I am actually enjoying the learning aspect of these problems. He just left for the auto parts store. I will give y'all an update when he gets back.

 

[GMCTRUCKS]

ppl told me the module can go bad or something, mine had about the same problem. I had a miss at idle but I had an exhaust valve too tight. I found it out by it sucking my hand on the tailpipe since I had duals I knew what side. I had to put a new dist. in mine, but not because of that miss, and they had kept telling me it could be bad. Even if it was new could be bad. I had always heard though too that egr or something else would cause it to try and die when coming to a stop.

FYI the idle can be raised, and not by the computer, the computer already knows the idle should be around 800 in park or neutral and 600 in gear. Messing with the computer aint gonna do a thing, it would have to be burnt into the chip.

They say you should not mess with the idle speed screw because it could cause other issues, or the idle being low is being caused by something else and would not fix the problem. The idle screw is covered by a cap on the tbi and has to be drilled out to get to it.

Have you checked your IAC? cleaned it off or cleaned out it's port? it could be screwed up or dirty.

If it's a replacement egr valve it could be casuing problems too. I heeard that unless it's a delphi or ac delco egr it won't work right and the numbers have to match.

check with skip white or whiteperformance on ebay they have them for around $65 or so complete and a warranty. I paid over $110 from autozone for mine and it did not come with a rotor or cap. I think the one on ebay does come with both.

I agree 100% on what is written above a wrong EGR can cause a bad miss and hesitation even new plug wires can be bad example if there cheap like Auto Zone brand check wire per wire. Check to see what your tech did to raise the idle I bet he messed something up. Hang tight we will fix it up. Make sure the EGR is for the right year engine.

 

[rico47635]

I forgot to say that my son looked at the EGR and said it looks new. That would make sense seeing as how the engine was replaced less than a year ago. I will have him check it out when he gets home. We don't have a vacuum pump, but sucking on the vacuum line should create enough vacuum to get it to work, correct?

And yeah, I am really starting to wonder exactly what he did to raise the idle. He told me the only way to raise it was through the computer, but didn't give me any more details. He's been my mechanic for the last five years, so I doubt he pulled any funny stunts. He has an very good reputation in this town and it's well deserved. He's been in business for years and has never been sued, unlike the other local mechanic who has a really bad rep for shoddy work.

 

[Swims350]

I'm not real sure on the IAC, it's been awhile since I read about it. I would agree with gmc on plug wires I've had it happen alot.

As for the egr no sucking doesn't matter, you need to actually see that it holds vac. you could try to see if you can suck the lugner inside up and it stay up, but I would just pull it up with it running to see if it changed the idle. it should and if it does not I think that means it's working good if not then it's bad. I'll have to double check on that one though.

 

[rico47635]

Well, much to my surprise my son just called and said the module checked out fine. They said they didn't have a way to test the IAC, so we're gonna get one anyway. Man, if this IAC doesn't fix the problem, and there isn't anything wrong with the EGR valve, then that pretty much leaves the distributor. I am not saying it isn't possible, but I've never seen a new set of plug wires go bad in so short a time. Now I am back to being frustrated! I thought we had this thing figured out. I sure appreciate all the help fellas.

 

[Toms94z71]

I had a miss at idle issue when i had the standard cr43ts ac delcos in my truck, infact I've had stumbling idle issues the whole time I've owned my truck with them in there, even after changing them twice, I went to the ac delco rapidfire plug part #1 and it has idled and ran so much better with them then it ever did with the standard ones for some reason.