idle problems

[firemedicsafd]

i have an 88 k5 with an idle problem. any time, cold or hot it idles at 1000 rpm or more. trouble codes i HAD were p022 and p043. I replaced the TPS and ESC and they went away. i have a computer to scan it but i dont know what numbers mean what. I can give a list if anyone wants to help me figure this out.

Second problem: During normal operations, it keeps cool...under 200 deg. sitting for a couple of mins she starts to get hot...close to 245 deg. I have dual electric fans that work...no temp probe to fail...new thermostat..set in the correct direction...water pump appears to be turning= no noise coming from it, full of the 50/50 coolant..and steel hoses. When i drive...she goes back down to normal temps but the n goes back up after a couple of minutes of sitting at idle. What is causing this thing to overheat?

Thanks for the help!

 

[496truck]

You prob need to replace the IAC (idle air control valve) on the pass side of the t-body. This controls your idle speed, most likely has failed. Easy fix and cheap at 20 bucks or something. Check your vacuum hoses for cracks/leaks as well.

 

[firemedicsafd]

wouldn't that trip a code?

 

[Stomis]

K forget reading codes like that with your fancy tools lol. This is an old truck get down and dirty old style and jump the first two pins from left to right with a paper clip.

Its gonna blink your codes at you 3 times each in succession. Ya gotta count the beeps, pause, then beeps. Thats your code by the chart I've always used fro CCC and TBI/TPI.

heres a link to a very detailed guide and list of codes: http://elcaminocentral.com/showthread.php?t=27196

Now figure out the codes and post em up here.

I'm guessing your heating problem is the same I had. Bad but not shot radiator cap. Turn her off and shes slowly evaping the coolant. Before I replaced my cap I could let me truck sit for a couple months and be down a gallon. Idling thats not enough antifreeze to open the tstat but when you get on it it splashed the T-stat and opens it.

Btw your idling could be from a faulty reading from not having constant fluid contact on the CTS. I know the computer is much more sensitive with the readings than the gauge.

 

[firemedicsafd]

the IAC has not tripped a code yet. When i got the codes from this thing i got them the way of the blinking light. By pure luck i replaced the cap with a pressure relief cap so we will see if that works or not. Thanks!

 

[Thunder]

Before you go replacing parts check all vacuum hoses for cracks or leaks.
Also the throttle body base gasket is a common problem. If it is bad and leaking it will usually cause a high idle, or other idle problems

 

[496truck]

My IAC did not set any codes. The idle was high with no CEL on either, hence no codes. I just did a physical check on it, unscrewed it from the t-body and found the little plunger was loose and could spin free. This is bad. New IAC can not move the plunger by hand.

But this is AFTER checking the basics, ruling out vacuum leaks...