Join Date: Jan 2015
Location: SW Wisconsin
oldeerslayer is online now
Re: S10 98 - no Idle
He's right, it wouldn't hurt to make sure the battery cables are clean and tight.
Diagnostic Trouble Code. If your service engine light is on that means that a DTC has been set. You need a cheap scanner to read engine codes.
All you need to check engine vacuum is a vacuum gauge. Just unplug the vacuum line running to your heater controls off the engine and plug the gauge into the line. Some even have a tee in them depending on accessories. Gauge should read 16-20 inches at idle and steady. If you have to hold it slightly above idle to keep it running the numbers will go down a bit, but still be steady. I'm looking for a vacuum leak here. That will kill an engine at idle, but should also set a bunch of DTC's. Check to be sure all hoses off the engine aren't off, loose or cracked. I often forget the one on the back of the air duct above the throttle body on 4.3's. That one isn't a vacuum hose but will throw the ecm in to convulsions because a bunch of air is entering after the MAF.
Look right behind the ABS module at the vacuum lines in that area. Those hoses tend to crack and come loose. Especially at the mileage yours has.
Cleaning the IAC won't help if it's electronics took a dump, but they are usually pretty reliable.
There are many possibilities for your problem, but this should get you started. Is yours a 4 or 6?