High/Jumping Idle after head gasket replacement

dcaplan

Member
:
Mazda Protege LX/2.0
I have a Mazda 2002 Protege 2.0 and just finished putting it back together after a head gasket replacement.
I'm now having an odd issue. When I start the car, the idle is really high (about 4000) then after a while it goes down to about 2000 and continuously jumps up to 2500 and then back down.
When the car is in Drive, it goes to normal idling speed but in Neutral and Park I get this issue. I thought it could have something to do with the IAC so i took it out and cleaned it with carb cleaner along with the throttle body but still had no luck. I'm really hoping it has nothing to do with the timing which I'm pretty sure I got right. For the timing, I aligned the marks, turned it several times to check if they stayed aligned, loosened the tensioner, turned it again a few times and then tightened the tensioner.

Any ideas?
 
Curious if you found what the problem is/was? I'm having the exact same issue after doing the VTCS delete a couple of months ago.
 
failing/dirty MAF, dirty IAC, dirty/failing TPS, massive vacuum leak, stuck EGR, could be a few things
 
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