The MAP is different for the MAF. The MAF is in line, between the air filter and the throttle body. Its the silver and black thing in the air ducting. If you unplug it and the symptoms are better, then get some MAF cleaner spray and spray the wires. Do not physically touch them!

 

it not the maf we checked that today.i have a mech look at it and he it stumped it like i have a ghost at time when he was looking for leaks around the upper intake he could get it to drop about 50 rpms with carb cleaner but it wouldn't die then he got water water all that did was jump it to 3800 4200 rmp but not in one spot it was different every time. it was look at with with he scanner it was all over the place rpm throttle 6.4% air flow was about 25.1 when it was going crazy.so lost dont know where else to go

 

Greetings
I have a new to me '99 Blazer. Just replaced the intake gasket due to coolant leakage. After the intake replacement the idle would run high on it's own. Might have been that way before, don't know.

These are the issues I found:
*Cruise control cable was tight. Needed some slack. Adjustment at the throttle connection.
* Changed some of the vacuum lines. I found the OEM lines had turned to "gum" when I tried to pull them off for the intake manifold gasket change.
* Changed the TPS. Sorry I didn't go through all the trouble shooting but for $36 on Amazon it was worth it to know it was good. Go with the OEM AC Delco.
* Changed the IAC with an Autozone part. Erratic high idle continued. Took the Autozone part back and put a new AC Delco IAC from Amazon. Works perfect. Also worth noting the idle is now at about 650 with the AC Delco IAC. The Autozone IAC idle was 500 when it settled down
* Noticed yesterday after all the other work that going to 4WD caused the engine to initially stall. It restarted but had a high idle. After a few cycles on the 4WD everything has settled down. Guessing an idle leak until everything was exercised. Older vehicles might need some new parts?

My vehicle has about 100K and looks like it hadn't been touched by anyone other than occasional dealer service except for a possible previous intake manifold gasket change which was done poorly. I could tell someone had been in there since original manufacturer in 1999.

I am an aircraft mechanic and by no means an expert Blazer technician.

 

I know this is old but, did you ever find a solution? I did the same thing, clean the TB then it wanted to drive it self.... I also replaced both tp sensor and iac..