blazer s10 high idle ...have codes

[chriskrebs]

Used the search fuction here, but couldn't exactly find the info I was looking for...

I have a 1993 blazer s-10 4.3 vortec 2wd
When driving 15 mph, it slowly accelerates to 16, 17, 18, 19 mph til I hit the brakes to slow down. If I throw it in neutral, it continues to rev.
It appears to get worse the longer I drive.
Can't tell you the rpm's (nortorious digital dash is out)

Also, as I previously posted my ac blows through the bottom vent when normal ac is selected. Could these be related? I checked for vac leaks under the hood and the dash and couldn't hear any.

I read previous posts and did the following:
cleaned EGR
cleaned IAC
and checked for vacuum leaks (didn't hear any)
Did a tuneup last summer (plugs, wires, air filter & PCV)

I did the paperclip trick and got codes 22, 23 and 35
if you could please ID these codes and tell me whats next, it would be greatly appreciated (im no expert mechanic)

Thanks in advance.
Chris

[bodace40s]

Originally Posted by chriskrebs

Used the search fuction here, but couldn't exactly find the info I was looking for...

I have a 1993 blazer s-10 4.3 vortec 2wd
When driving 15 mph, it slowly accelerates to 16, 17, 18, 19 mph til I hit the brakes to slow down. If I throw it in neutral, it continues to rev.
It appears to get worse the longer I drive.
Can't tell you the rpm's (nortorious digital dash is out)

Also, as I previously posted my ac blows through the bottom vent when normal ac is selected. Could these be related? I checked for vac leaks under the hood and the dash and couldn't hear any.

I read previous posts and did the following:
cleaned EGR
cleaned IAC
and checked for vacuum leaks (didn't hear any)
Did a tuneup last summer (plugs, wires, air filter & PCV)

I did the paperclip trick and got codes 22, 23 and 35
if you could please ID these codes and tell me whats next, it would be greatly appreciated (im no expert mechanic)

Thanks in advance.
Chris

Maybe your TBI- throttle control sensor..

Crystal

[blazee]

22-Throttle Position Sensor or circuit - voltage low
23-Intake Air Temperature sensor circuit
35-Idle Air Control valve or circuit

[BlazerLT]

Originally Posted by blazee

22-Throttle Position Sensor or circuit - voltage low
23-Intake Air Temperature sensor circuit
35-Idle Air Control valve or circuit

I would replace the TPS (throttle position sensor) before anything.

[chriskrebs]

Thanks, all. I will let you guys know how it went.

[chriskrebs]

i changed out the throttle position sensor this a.m.,
let car idle for 5 minutes.
when in drive it was smooth for 100 feet, then the idle increased.
when it shifted into 2nd, the wheels chirped, idle remained high.
shut off, disconnected battery for 5 minutes.
took off and motor now surges for 5 seconds, idle drops for 5 seconds then surges again (an ongoing cycle)
put it in park and idle remains high
Could i have installed the tps incorrectly, it seemed pretty straight forward.
Please advise what's next.
Thanks
Chris

[blazee]

Diconnecting the battery should have cleared the old codes. Did the light come back on when you restarted the engine? If so what codes do you have now?

[blazee]

Are you sure it was the IAC that you cleaned?

[chriskrebs]

the light was off untill the idle kicked up again, bout 100 feet
re-read codes now have 22 and 35

[chriskrebs]

i looked up the pic someone posted on the iac.
has a little piston with spring around it, cone shaped head.
cleaned this and the hole with gumout

[blazee]

Check your connections and wiring for loose connections or damaged wires. Check at the computer and where the wires pass through the firewall and anywhere else that damage is likely.

[chriskrebs]

i checked all wiring i could access, doesnt appear to be any damage.

with the new tps, it would idle fine until i gave it gas. this would raise the idle so that it would accerate out of 2nd and chirp the tires. It was difficult to stop when parking. Putting it in reverse, to park, the tires would chirp again.

this was worse than before , so i put the old tps back in, and (of course) i'm back to the same symptoms (but no ses light yet, and no old codes stored).

Could i have gotten a bad tps? any thing else i can look for?

[BlazerLT]

I would check for vacuum leaks.

[chriskrebs]

I already have (checked for vac leaks), what I dont understand is why the new TPS would make it worse.

I have only cleaned the IAC, is it possible that I need a new one?

Anything with the EGR possible? I cleaned a carbon chunk out of it about a month ago when it was running rough. Other than the high idle it runs really smooth. Thanks.

[BlazerLT]

How did you check for vac leaks?