1989 420 SEL Breaking-Up & Not Starting when Hot
 

OK, a week ago upon acceleration under load semi-aggressive it started breaking up and had to feather. It continued and under light acceleration it would be ok, but if you turn on the a/c it would break up heavily, obviously I turned it off. Went to Bank came out car would not start but tried to almost like a dead battery.
Towed to shop, mechanic says new battery and works fine now that was the problem. NOT!!
Same day i got it back from mechanic it started breaking up a little again. I took it home and did not drive for two days...
Car started yesterday evening just fine, went to store, came out and had trouble starting so I went directly home, turned it off and tried immediate re-start... would not start.... Next morning started fine.

So seems like when its hot it doesn't start, and that just running drains the battery system, and a/c makes it break-up (probably again takes to much power from battery system).

Does this sounds like a coil issue? Fuel Relay/Pump....? Rotor/Cap/Plugs/Wires?


FYI - The Problem was the Voltage Regulator on the Alternator - also 9/10 times its this and not the alternator itself...

Help!!
Lance - AKA "Skippy T"

check that your alternator is putting charge into battery.

Yes, Mechanic said alternator was "putting out"...

FYI - Voltage Regulator Caused these issues... Cars Runs Great again!

The voltage regulator is part of the alternator, so his assertion that the alternator was "putting out" was both incorrect and easily misconstrued :D