Has anyone seen Idle surge caused by bad MAS

[Gula]

I have sever idle surge. It idles from about 1700 to 2100 rpms about twice a second (very annoying).
I tried 3 different ECMs, and just bought a entire throttle body with all the sensors from a car that did not surge. I put it on this weekend and no good.

Another problem I was having was at part throttle (about 8-12%) when I am backing off it bucks. So looking for problems I notice on my SAFC my Karmon Hz spikes up to 2000 Hz (from about 150 hz) when this happens. So I figure its a bad MAS so time to upgrade to a 2g MAS.

I thought these problems were seperate but out of curiosity I unplugged the MAS while it was idleing and the surge went away.

I have yet to put on my 2g MAS but I was wondering if anyone else has seen this problem.

PS what is the best site recommended to do the wiring swap. (I saw the one in the FAQ).

Thanks

 

[WatchItExplode]

I'm bumping this thread because I have some useful information to add on this topic that I haven't found in other threads.

I was having the typical idle surge issue, as well as my engine dying when it's fully warmed up and letting the RPM drop. I tried EVERYTHING in the VFAQ, searched all the idle surge topics, etc. Tried different ECU's, boost leak test, etc. I even went and bought a new ISC even though mine check out "okay", just because it was the last thing I could think of. No dice.

Well the other day I replaced my 1g MAS with a 2g MAS. I was just doing it as an upgrade, I didn't even think it would help the idle surge. But to my surprise, the idle surge completely disappeared. Not to mention my throttle response is better, idle is steadier, engine warms up faster, and the car just overall runs better than I thought it ever could without any form of tuning.

So to answer the question the thread starter asked 2 years ago: yes, idle surge can be caused by a bad MAS.

 

[Gula]

Wow, back from the dead post. It's been over a year since I have been on the site but this just came into my email.
I guess I never posted back on my own thread, but just like you a 2g MAS swap cured all my problems. My car has been down with a blown head gasket for over a year (I have been too busy to fix it) but I may get back into it soon. Thanks for the wake up call.

Gula