94' s10 idle problem and drop in RPM

[Carystodd]

it seems to only be a problem when its 90 degrees + out. ive replaced idle air control valve, egr solenoid, o2 sensor. when started idles 2000 to 2500 but idles down after few min. is there anyway to get a code on a 94? i tried jumping the leads with a wire but nothing happened.

[MT-2500]

Originally Posted by Carystodd

it seems to only be a problem when its 90 degrees + out. ive replaced idle air control valve, egr solenoid, o2 sensor. when started idles 2000 to 2500 but idles down after few min. is there anyway to get a code on a 94? i tried jumping the leads with a wire but nothing happened.

You can jumper A and B pins and read codes from check engine light.

Is it a standard or auto transmission?
After the fast idle warm up does it idle OK?

[MT-2500]

Has it always been like that?
Or just started?
Any check engine lights on?

[Carystodd]

it started last summer. no check engine lights. when i first start it up it idles high then after few min idles down. but when i drive about fifteen miles when its really hot out and stop at a light or stop sign it will idle really low and then cut off. i can restart and drive a few more miles and it will do it again.

[MT-2500]

Originally Posted by Carystodd

it started last summer. no check engine lights. when i first start it up it idles high then after few min idles down. but when i drive about fifteen miles when its really hot out and stop at a light or stop sign it will idle really low and then cut off. i can restart and drive a few more miles and it will do it again.

Try to get codes from computer.

Check IAC valve.

[Carystodd]

cant get shit off computer. it must have been redone by someone at one point because its the 20 pin plug but their is only 3 wires going to it and i bought the code reader but it didnt do shit. i found what looks like a vaccumm house going to a 3" ball in the top right under my hood. could that be my problem?

[MT-2500]

They only make 12 or 16 pin test connectors.

16 pin one is ODD 11.
Some 94 1/2 and 95 require a special engine capable scanner to read codes and engine data.

Is the vacuum lines to the ball good and good vacuum to it and engine holding good vacuum?

What is engine idle vacuum reading and vacuum at 2 K rpm?

[MT-2500]

http://www.troublecodes.net/OBD2/

http://www.troublecodes.net/GM/
Does yours have a A and B pin like this?

[Carystodd]

yes pins look exactly like that but there is only 3 wires in the pins. 1,2 and 9. and as far as the the vaccumm hose there is one cracked and they are dry rotted pretty bad so i need to replace them now

[MT-2500]

Originally Posted by Carystodd

yes pins look exactly like that but there is only 3 wires in the pins. 1,2 and 9. and as far as the the vaccumm hose there is one cracked and they are dry rotted pretty bad so i need to replace them now

Yes fix vacuum lines and if that does not hel start looking for the 94 engine capable scanner to check it out.

[Carystodd]

i will deff do it. how much a scanner set me back?

[MT-2500]

Can run into 3-5 grand for the good engine capable ones.
Plus 500 to a 1000 us$ a year to keep them up dated.

For a one time deal find a good repair shop that has one.
They usually charge a 1/2 hr to hr to check it out.
Lot cheaper than buying a good scanner.

Let us know how it goes.

[Carystodd]

alright yea ill go get it checked out. would a code or something come up even if a check engine soon light WASNT coming on? i really do appreciate your time.

[MT-2500]

Originally Posted by Carystodd

alright yea ill go get it checked out. would a code or something come up even if a check engine soon light WASNT coming on? i really do appreciate your time.

Yes a scanner check will show past and history codes and a sensor read out may point to the problem.

[Carystodd]

alright i replaced hoses and still didnt fix problem. i called my bosses mechanic and he said he can scan it but it wont tell him much. im gonna leave the truck with him monday morning and hopefully find somethin out.. ill let you know. once again thanks for your time