parkermoto

So I've been going through my 1994 C900 vert- (2.1L N/A 16V) making a lot of long overdue repairs and I've created a new problem.

It all started with me fixing the AC- which had been cycling on and off and blowing high pressure valves at the compressor. I deduced that the pressure build up was due to a clogged expansion valve so I replaced it along with the drier.

While replacing those parts I ended up cracking a bunch of vacuum hoses that were badly deteriorated along with the larger pcv hose that runs across the block from the pcv valve to the throttle body.
I ended up up replacing all the vacuum lines with new 4mm hoses from a local auto part store and the molded pcv hose with a generic hose from the store as well. I also noticed during this repair that the brass coupler that fits into the throttle body is loose and came out with the pcv hose. The grommets from the engine block that hold the nipples that lead to vacuum lines all seem pretty loose but I haven't yet replaced them (waiting to receive new ones currently) though they were loose before the repair and it all seemed to work fine. I took a little bit of flexible gasket sealant and made those connections more solid and they seem to hold well. How important is it that these are "solid"?

Also while doing the repair i discovered that my charging output was inadequate and I diagnosed a bad voltage regulator at autozone using their test machine. I replaced the voltage regulator and also added an additional grounding wire from the alt to the negative battery terminal. In addition I cleaned up a number of grounds to the engine by buffing wire terminals and exposing better metal at the block. Charging is now normal at 14v.

All that said- as soon as I started the car after the repairs I ended up with a surging idle- like 2000-500rpm and back again every second. The car then flipped a check engine light and the idle normalized but the car is in limp mode and has low power.

I then set about looking for the issue and checked all the vacuum lines but couldn't find a leak. I've checked this a few times with carb cleaner but don't notice any change in idle no matter where I spray.
I took out the IAC and cleaned it thoroughly and also cleaned the AMM and all electrical contacts. Also cleaned the throttle body but still no fix.

With the check engine light the car idles fine (though high at 1000rpm) but drives sluggishly. If I disconnect the battery and reset the check engine light the car has the surging idle but then sometimes normalizes and drives okay for a while at full power though even while cruising on the highway the check engine light flips back on.

I disconnected the AMM while the car was surging before the light went on and the car stalled but then when I plugged it back in and started it up again the car ran normally with no check engine light- then randomly it came back on.

I'm not sure what to do next except triple check the vacuum lines and see what else it could be... Anyone have a foolproof (easy) method for locating vacuum leaks?

If anyone has any ideas please suggest them. Also- I would love to try reading the flash codes but I believe I need a special "ISAT" connector to do it on this car? Anyone know if you can do it just with the regular wires or some other configuration?

Also- if anyone knows specifically how to test the AMM or eliminate any other variables let me know. Getting frustrated because it ran well before...

Thanks in advance!