Got my new pigtail and iac in the mail today and went ahead and installed them, didn’t quite have the effect I was hoping for. When I started the truck up to get it to temp it did start and idle differently than before, a step in the right direction. So I went through the pdf you sent and set the base idle according to instruction but the iac still will not close when the an and b terminals are jumped. What I ended up doing is starting the truck like normal and seeing the pintle closed all the way I would unplug it and then set the idle like that, after that the truck didn’t want to start had to give it a little throttle went for a drive and there’s a major differnce in the way the truck performs in the low end. It’s much better now but it still bugs me that it won’t extend when the an and b ports are jumped, currently truck starts and drives great. After the test drive it fires up fine so I think I’m going to drive it a bit and then try setting it properly.
I went through a bunch of problems when I replaced mine too.
But that was the same day I rebuilt the throttle body and put a new IAC and pigtail and a new TPS and temp sensor.
And a lot of new grounds.
That was the same day I put the new distributor in as well.
I bought the NOS part inventory from a shop that was going out of business and replaced all of my old parts with new all at the same time.
This is when some of the more experianced guys on this forumn will tell you that you need a scanner.
And you should get one if you are going to keep the truck.
But that doesnt help you right this minute.
Sometimes I think that if you were air dropped into Mexico and you went on this forumn asking about how to find the bathroom, some of these guys would tell you to just shut up and learn spanish.
I fought with mine all day.
Most of the procedures would not work correctly and every time I got one thing to work something else stopped working.
It was the battery cables.
Bad ground and low voltage to the ECM during relearn/reset.
If you have never replaced your battery cables they are bad.
They look brand new from the outside.
But wire rots inside of the plastic side post connections.
At the end of that wire and inside of that sidepost connection is a ring terminal on the end of the wire.
The wire corrodes and that ring terminal rots but the only damn miracle bulletproof plastic GM ever made is that coating on the ends of the battery cables.
When you tighten down an old GM side post connection the plastic reaches torque BEFORE the ring terminal has good contact.
It is binding on the plastic. Not on the ring end of the wire.
The plastic tightens up before the wire makes a solid contact.
Many many many people will tell you to go buy brand new GM battery cables.
But they might not work with an aftermarket battery.
And who has a genuine GM battery these days?
GM sidepost batteries have a plastic coller around the contact.
A type of a "standoff" connection.
That "Standoff" varies in my experiance about plus or minus about 0.125 or so
The only way you get any somewhat decent connection on an aftermarket battery is if that coller is 1/8ths short.
If its 1/8ths long you get nothing.
Take a pair of dikes or sidecutters and cut all of the plastic off of both ends of your battery cables without cutting the wire or the ring terminal.
They will be rotted.
I have never seen an old one that wasnt.
I can get you down the road for about 4 bucks of bolts nuts and washers without buying new battery cables.
Let me know, its really easy and Im on about year 5 or so of this rig.
The ecm relies on finding certain steady voltages from the various sensors.
Bad ground, low volts, high volts, intermittant, etc..
It doesnt meet the parameters and it wont reset.
And that all changes when the wires get hot.
Pretty much any strange bizarre thing that happens on any side post Chevy will turn into a friggen tail chase if you dont fix the sideposts first.
That might not cure your problem, but at least you will know that it isnt the problem.