My father has an old '83 240 DL Wagon, The thing is on it's last legs (Physically and Mechanically) if you ask me but still Runs and Drives~And he seems attached to it.

Other than random annoyances, It seems to have an unknown engine or possible electrical issue I'm not being able to pin-point.

It's loping on idle, Surging kind of~Especially heavy at cold startup but still continues throughout driving it.
It will even *Almost die* right after a quick rev or on ocassion it does die.

The whole engine shutters and stumbles as it rotates on idle.

Not long ago he had a major issue coming home from work. Which leads me to believe it could be something to do with electrical:
He went out to start it and come home from work, And it wouldnt start (no juice).
He got a jump start and mostly rolled home with extremely low power.

We then couldnt get it started again.
The battery was bought a week before brand new, And we had been suspecting the alternator~
So I pulled it out and took it over and had it tested, After 3 run throughs it tested perfectly fine...

got back and hooked it back up, and no difference.
Hooked up a battery charger and let it set, got it running but it drained down again.
Hooked up a multimeter and it read fine with key off, But noticed an IMMEDIATE drain a soon as the key was turned any direction.

Looked for any wiring damage under the hood, checked all fuses, looked for any trouble signs~Found nothing.
After tinkering around for hours it just randomly started up and stayed running, then continued and has continued to run ever since.

Also, I was riding passenger the other day (and waited out in the car) while he was doing some things, And it started loping/idleing hard again~So i started smacking around the dash, playing with switches and what not looking for any changes, After i cranked the A/C (doesnt work) all the way up the idle smoothed out a bit...

Some weird things going on here, Any ideas? Engine computer maybe?

 

Doubtful the computer is an issue on an 83. Those cars had KJet mechanical fuel injection. The 83 is smack in the middle of the years that had biodegradable wiring insulation. The idle smooths out because there is a small cylindrical device on the firewall that idles the engine up when the a/c is on. You most likely have a few minor issues going on. I'd first check the idle air control valve a/k/a iac. It is located underneath the intake manifold on the driver side of engine; a horizontal cylindrical object w/ 2 rubber hoses going to it as well as an electrical connector. It'spossible the iac has a. failed b. connector is bad, loose, corroded c. hose(s) are rotted, failed d. simply needs to be removed and cleaned out.
It's also quite possible that other smaller vac hoses on the engine have failed causing the erratic idle. An hour's worth of inspection could prove invaluable.

 

Thanks for the reply.
I'll get out and do some more inspecting and play with the IAC when the weather calms down.

Also forgot to mention its down on power, Very sluggish when you hit the gas.