blazer s10 high idle ...have codes

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

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

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

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.

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

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

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?

Are you sure it was the IAC that you cleaned?

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

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

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.

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?

I would check for vacuum leaks.

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.

How did you check for vac leaks?

I listened and looked and disconnected and reconnected the vac lines I could ID:
T behind distributer cap, one is capped, one goes to round cannister, one terminates to the back of the throttle body
brake booster
pcv
thats all I saw
I'm missing some, right?
If you could help me ID the rest, could I spray carb cleaner at the connections, to see if it sucks it up?
Thanks again for your help

You should have vac line going to:

-Brake booster
-Vacuum ball in the engine compartment for the heater controls.
-4x4 transfer case vacuum actuator.
- PCV valve
- EVAC purge system.

Carb cleaner would be an excellent way to find out if you got a leak.

Spray the ends and along the hoses and if your engine rpms pick up, you have found the possible leak.

Results of the vacuum leak check:

Brake booster: none at the booster, slight rise in rpm going into motor
Vacuum ball: None at the ball, none at the "T".
4x4 transfer case vacuum actuator: have 2x
PCV valve: slight rise at valve, none going into the TB
EVAC purge system: None at the cannister, none were line goesin under the butterfly
Sprayed near EGR, slight rise, but verified its mounted tightly
Sprayed near IAC, slight rise, removed, cleaned again and re-installed

Still getting codes 23 and 35

On test ride, she'll idle 7mph consistantly til I give her gas, then she acellerates slowly up til 13-15 mph

Another thing I noticed is, it isnt as bad when cold, when at operating temperature, she'll really take off.

Any more thoughts?

I feel I'm beating the crap out of the motor and brakes.
Thanks
Chris

Might be a dumb question, but have you reset the computer yet?

I disconnected the negative terminal for 5 minutes after I put the old TPS back in, is this sufficient?

Should be, but I would do it again and remove the two ECM fuses from the fuse panel as well just to make sure.

I would wait maybe 15 minutes.

I removed fuse marked ecm 1, waited 15 minutes.
Ran it for 5 minutes in drive with brake on and shut down.
Read codes again still got 23 and 35
?????????????

oops missed one will try again
sorry

Turn the key to the on position, remove the two fuses for ten minutes.

Turn key off after 10 minutes and reinsert fuses.

done.
it cleared all codes, drove around the block but it still accelerates when in gear.
Did not get ses light (yet)

You must have a vacuum leak somewhere or your throttle butter fly is stuck partially open.

Turn the key to the on position, remove the two fuses for ten minutes.

Turn key off after 10 minutes and reinsert fuses.

My haynes manual says diconnecting or reconnecting power with the key on can damage the ECM.

I checked for leaks (see previous post), would this slight rpm rise account for the self-acceleration? All hoses seem to still be pliant and seated.
I have cleaned the butterfly and throttle opening with carb cleaner and a shop rag.
When I open and close it, it appears to seat properly.
What if i had someone press the gas, while I watch the butterfly, would I see anything even with it in park?
Could it be something with the cable?
The idle (tho a little high) maintains until I give it gas, then it gradually accelerates. Sometimes it maintains at 35 mph, after rising from a standstill.
I'm trying to give as much information as I can.
Thanks for hanging in there with me.

I did it to mine and I didn't get any damage.

You can damage removing the fuses, but you can damage it inserting the fuses.

That is why I said to turn the key off and reinsert them after 10 minutes.

I checked for leaks (see previous post), would this slight rpm rise account for the self-acceleration? All hoses seem to still be pliant and seated.
I have cleaned the butterfly and throttle opening with carb cleaner and a shop rag.
When I open and close it, it appears to seat properly.
What if i had someone press the gas, while I watch the butterfly, would I see anything even with it in park?
Could it be something with the cable?
The idle (tho a little high) maintains until I give it gas, then it gradually accelerates. Sometimes it maintains at 35 mph, after rising from a standstill.
I'm trying to give as much information as I can.
Thanks for hanging in there with me.

This still sounds like a vacuum leak.

Could Be Your Throttle Body Is Gummed Up. Keeping Your Butterfly From Closing.