Wife called today w/ 245 running poorly after rain; thought it was wires; she said then it suddenly started running OK; drove 20 miles fine; parked for 5 hrs(no rain now); broke down after going 2 miles; put in new wires to no avail; disconnecting AMM (while off) made idle much better, but still ran poor (can't get up hill), borrowed AMM from '91 244 (son's girlfriend just bought one, said NOW she feels part of the family)(4 Volvos); after swapping AMM still runs poorly, barely starts but disconnecting AMM helps idle! Can't get up hill in "limp home" mode but it can't be the AMM anyways. What's going on? TIA.

Sounds like AMM to me.
When I see AMMs in the pick a part, I grab them. Cheap insurance.
I always travel with 2 or 3 replacements. Good luck.

Any holes in the Bellows from AMM to Throttle body? That screws up the air mixture. Take the Bellows off and inspect, usually the bellows rubbs and wears a hole by the Strut tower.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

Thanks I'll check the bellows when I get off work. Got the codes 113, 232, and 121, which is AMM wiring?? I already swapped AMM's. Any ideas on the wiring?

I haven't read anything here about AMM wiring going bad. Other wiring, yes, but not in this area.

You got these codes with your AMM in the car or the swap in?

Check the pins in the connector to see how crapped up they are or if any bent out of whack.
The AMM's had the same part number? Just wondering if yours was bad and the Swap-in was the wrong one.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

The codes were actually with the swapped one in. The AMM's were the same part number. Haven't checked the pins yet. Any other ideas?

Still wondering if it's AMM related or Rain related or one caused the other.
No other ideas at this time. Any sign of it running rich or is it just running crappy?
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

Is this just an idle problem - ie. if you run the engine at 2000 rpm with the AMM connected, does it seem OK? If so, do the following:

Can you hear the TPS click when you rotate the throttle off its endstop and back? This is required to make the idle air control valve operate. If it does click, its likely fine, although the definitive test is to read it at the ECU.

Assuming the TPS is fine, you should consider cleaning your IAC valve.

--
David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto

Clean IAC valve? Please elaborate. Thanks.

For the umpteenth time, you can't drive normally without a good AMM.