!!!!!!High Idle & Throttle, Help!!!!!!

I have recently replaced the engine (4.3) in my 97blazer. I am having trouble with the idle being high and the throttle continuing to accelerate. I wil explain, when starting the engine it will idle high and often stop and return to normalthen when i drive it, it accelerates not fest it is a gradual acceleration. and when I stop at a stop sign it takes a moment for it to kick back down to idle speed.
I have replaced all the vacum lines except the one that goes to the heater controls in the dash area, and the heater controls work fine. The throttle posistioning sensor has been replaced, I do not believe there was any adjustment on it, and the idle control valve has also been replaced. I have also checked around the upper plenium for leaks with gumout, spraying all around it. I still have the problem. his is driving me crazy can anyone help me solve this problem? I have a long trip I must take this weekend and need to have this corrected. I have been getting the error code P0507 it has been reset several times and keeps going off. :screwy: I have also replaced the PCV Valve. Could this be a problem with Timing? Am I correct in thinking that there is no adjustment in the timing on a 97 4.3 Blazer? :confused:

I also replaced the PCV Valve Could this be a problem with the timing? Am I correct in thinking that there is no adjustment in the timing on the 97 4.3L?

I have to go to class I will check in later this evening I really appreciate and need your help

Thanks

Remove the new IAC valve and clean the port that it installs into and if it is dirty, clean the valve too.

I will attempt that now before class

THANKS!!!

High idle like that is usually from a vacuum leak.

The heater control vacuum lines should be definitely checked out seeing they are the ones that usually will start to fail.

Also check where the EVAP puge line connects to the engine as well.

Are there any check engine lights?

High idle like that is usually from a vacuum leak.

The heater control vacuum lines should be definitely checked out seeing they are the ones that usually will start to fail.

Also check where the EVAP puge line connects to the engine as well.

Are there any check engine lights?

Blazer LT

The code that keeps coming up is P0507.

What is the process for checking the heater control lines, also where are the EVAP lines that enter the engine?

I don't know much but I am learning fast

Thanks for your help I will check in the AM for reply, I will check in the AM for reply, If none I will look in my haynes for direction then check back around noon. Thanks Again

I removed the IAC valve and cleaned. Still get the same result.

I removed the IAC valve and cleaned. Still get the same result.

Measure the IAC valve pintle length from the end of the pintle to the flange.

It should be 1.10 inches or 28mm if memeory serves me correctly.

Check all the vacuum lines going to and from the engine and make sure they are not cracked, disconnected, or not seated properly.

Did the problem exist before you replaced the IAC? The Haynes Manual says that there are ones with different tapers. If you got the wrong one it will not seal properly causing a high idle.

You can also try cleaning the bore of the throttle body. Sometimes carbon can build up and hold the butterfly open a little.

If none of that is your problem, then I would have agree that there is a leak somewhere.

Either a vacuum line somewhere, like BlazerLT said.

Or an upper plenium gasket leak, like ricksza said in your other thread on this problem:
http://www.automotiveforums.com/vbulletin/showthread.php?t=400404

I am now getting code P0122, P0123
Throttle /Padal posistion sensor switch A circuit low input for 0122
Throttle /Padal posistion sensor switch A circuit high for P0123
I am thinking that I have damaged the fitting that hooks into sensor i am going to get one and will let you know thanks

I think the problem is solved The 0122 & 0123 code were for a bad socket in the sensor, it was replaced. As for the P0507 code all the sensors and greif were not necessary, it seems that the problem was in the throttle cable. There is an adjustment at the end of the cable that allows for adjustment of the cable so that it sits properly against the throttle housing. :banghead: At least I should not need to replace any sensors in the near future.
I thank all of you for your assistance. I will be back soon to seek help in other matters as I still have plenty of work to get this blazer up to my standards.
Thank you

Well guys (& gals) I thought the problem was solved but it is not I am still getting the error code P0507 and am now getting the code P0113 also.
Any ideas? could it be the computer? need help to save sanity. Thanks

113 is for the IAT sensor.

I removed the IAC valve and cleaned. Still get the same result.

p0113 ia an IAT code. Did you remove and clean the IAC or the IAT? They are two completely different things.

If you cleaned the wrong one, that would explain why you are still having the same problems and if you damaged it, that would also explain the P0113 code.

Yes , I replaced the IAT and the IAC. Did not get code 0113 until I put in new one. I put old one back and still get 0113

Always reset your computer when you take out/exchange/clean sensors. Try that and see if the truck still throws a code at you.

How is that done?

Disconnect the battery for ten minutes to reset.

Thank you,
I am going to do that now, i will let you know how it goes.