I'm back...somehow I always manage to have the strangest issues.

Anyway, recently I've been having hesitation/bogging (and idle) issues that no one can figure out. I've replaced the MAP, the IAC unit, air filter, cleaned the MAP channel, etc...I did everything logical, and it's certainly adding up. I had a thread a month or two ago about it.

Anyway, I've noticed that since the new IAC was installed, the car will now rev itself on its own once I start driving(*), when it's still warming up. Basically, it runs to between 2-3K rpm, about 3 or 4 times. It's noticeable enough that adjacent cars think that I'm beefing them. It's not a problem, per se, but it's ridiculous.

Now, I notice the new IAC is gold-colored, whereas my old one is silver. Could it be that it's a different unit (maybe for an AP2?), and that's what is causing this? Has anyone ever experienced this? I couldn't find anything...

Thanks!

(*Obviously I'm not driving hard when it's still cold, etc.)

 

Check the connection on the IAC plug...it can sometimes not seat all the way.

Also, reset your ECU.

BTW...are you supercharged?

 

This happened to me for a little while after my engine was hydrolocked...eventually it went away, I was thinking that it was some water still in IAC ?

 

iac have a good seal on it? idle at a normal rpm? any check engine lights? could timing be thrown off due to cks or cps? any power loss? when the problem started was it gradual or was it instinatious? can you manipulate the throttle to get it to clear up?

 

hey man, you're always the first to respond to my issues! i appreciate that.

plug seems like it connects solidly, i've reset the ECU (well, pulled the backup, i assume that's just as good as disconnecting the battery?)

nope, not supercharged. i'm essentially stock, engine-wise (as far as this is concerned, at least).

 

hi, thanks for the reply.

1. the IAC seal seems ok - i didn't double-check again, but i watched it go on and all seemed normal.

2. when it idles well, it's at a normal RPM, yes. it still dips and then overcompensates (excessively, not the normal dip) when coming out of gear, though, but not like before it was replaced. before, it wouldn't return to idle from any rev, period. it would just drop and die, or if i was lucky, barely hang on, shuddering wildly at 500 RPM.

3. no CEL's.

4. timing is 100% dead on. (compression couldn't be better, also)

5. there is indeed significant power loss, only intermittent and only at low RPM. here's my last thread about that: https://www.s2ki.com/forums/index.php?showtopic=663674 - it's not resolved, but i didn't wanna keep bugging the forum if no one could figure it out. basically, pushing in the throttle further won't produce additional power (although it is opening the butterfly - exhaust gets louder), it's like it hits a wall, like i'm towing a 18-wheeler.

6. this self-revving problem started instantaneously, nothing gradual.

7. it still responds to the throttle when it's revving itself, yes. when it returns to idle, it's no longer doing it.

 

honestly it sound kinda lke the egr valve is stuck open where you located if its local i would be happy to look at it for you. or maybe a clogged cat? what do the plugs look like?

 

I don't think we have egr valves.

My new one looked just like the old one, but new, not gold.

injectors? mo $$$ I know.

 

disconnecting the battery only works on obd1 and pre

 

well a closed iac is a closed iac reguardless of right or wrong as long as its sealing. i would be shocked as hell if we didnt have egr valves. i could go check my car but its chilly and not tonight lol. injectors would give you a misfire code. im not sure if our injectors are saturated or peak and hold. i think they are peak and hold so you might wanna do it the fancy way and pop the injector rail out turn it upside down and see if everything is firing in correct pules. also check for node and signal on the coils. should have constant power and pulsing ground i believe. i gotta get up early so im going to bed but ill be back on tomorrow to try and help you.