It's me Michael. Your worst nightmare is back already. I have been plodding through the testing. EGR, PVC, O2, TPS. I got to the IAC. My chiltons says infinity ohms on one side and 20 to 80 on the other two terminals. Alldata says above 20 on both. Go figure. I have infinity (0) on both. My friend says that infinity is absolute 0. I am not into ohms. Meter set at 200 I have a starting 1 that gos to 0 (infinity)? Do I replace, adjust or push the Trooper off the new Narrows Bridge? And could this be so important as to put the truck in a total preformance shutdown?

I did start the trooper when I had all kinds of things disconected just to see what I could get (it died). I did get a reading off the ecm (33) so I am starting to come over to your thinking. Whats the air pump (it must have a 3 letter abev.) called under the alternator? Is it important?
You've been a great help. Thanks Stan

Of course it has a three letter acronym. That would be the AIR pump. Well, it would be better described as the pump part of the AIR system. Air Injection Recirculation, I think. The pump pumps air (lowercase, nown) into the exhaust to enhance the combustion of hydrocarbons post engine, usually in the CAT.

This is where Chiltons falls down. I believe the procedure they have in there is for the 2.6. I don't see something specific for the 2.8. Personally, if I were you, I would adjust it as described by Jim Paget in the last link I gave you above and go from there. At the least, you will be able to see if the IAC responds.

As far as infinity vs 0, we'll leave the theoretical mathematical debates for those who find them interesting. For all intents and purposes, infinity means an open circuit, i.e. no continuity. Any kind of continuity will give some sort of resistance (ohm) reading.

Personally, I would start looking over at the s-10 forum that is referenced in some of the posts I gave you. These guys will know their 2.8 stuff way better than Mr. Chilton.

All I can say is keep at it. I don't want to have to come over and fix it for you. <img src="/forums/images/graemlins/smile.gif" alt="" />

Michael

PS: Jim Paget and EdMc are going to be getting coal in their stocking for not helping out here. <img src="/forums/images/graemlins/evil.gif" alt="" />

By the way, the IAC adjustment procedure came from an S-10 manual via JohninLV.

Hey Santa. Your list finally brought the present I was looking for, I think. This morning I finished working my way down your list, except for the IAC adjustment. I wasn't comfortable changing any settings just yet.

I read the rest of your reply and I noticed you had said something about TBI spray patterns, but it couldn't be that, that's to easy to check, sides I had just noticed those fans a couple weeks ago. So I put everything back together. Fired it up sure enough there's a spray pattern. Wait a minute, there's only one pattern I think. I'll get a stronger light, nope the other one is not there. I'll rev it up, probably like a 4 barrel it will kick in. Let it warm up, tap on it, nope only one pattern.

So I am off to get a couple new injectors. I hope that fixes it. I will definitely let you know.

Thanks Stan

PS Mr. EdMc will be hearing from me because I am looking at a 3.4 out of a 94 Camaro. I have to verify it's the right engine. S in the VIN, right. Anything else?

Since I complained about not getting the final solution to a lot of the problems on this board I have to let everyone know the final outcome to this issue. It was a plugged injector. I wish I would have looked at the injectors first. Instead, I worked my way through MichaelÆs list from top to bottom. Always do the easiest and the obvious first.

After I got the injectors in, the idle was at 1400rpms. So I started checking around, easy stuff FIRST. I found the fitting connected to the PVC valve was cracked, letting to much outside air in. All the wrong tubing, too. I got an OEM out of Pull A Part. That brought it down to 1000rpms. Still to high, easy stuff FIRST. So I squirted a little WD on the tbi throttle linkage. That took it to 800rpms, just right.

The replacement parts came cheap from a WY. But the only two gaskets I needed came in a little kit that cost $36. Going to make my own next time.

I want to thank Michael Clark for sticking with me on this issue. I didnÆt always believe what he was trying to tell me. These Moderators do a great job and they give a lot of their time. Thanks, Stan