Sunshn

Hey Olds fans,

72 Cutlass Supreme Convertible with a 350 Rocket 2bbl. Engine is (or was I guess) running perfectly, regular service, sounds like a dream.

Took her on a 2 hour road trip last week, stopped at a couple places. After the second or third stop (after about 1.5 hours of driving), upon trying to start the car for about 20 seconds, the engine hesitated, and started to draw flat, interior lights flicked on and off a bunch of times.

Started right up on second attempt, pretty convincingly, not much hesitation. Radio had reset.

Upon leaving it parked overnight, fired right up the next morning (radio reset again). After driving for about 20 minutes, shut off car (Generator light lit up) Attempted restart, some hesitation, but did start.

Radio reset again. Since that weekend, the car struggles to start, though I've only driven it twice since then. Radio resets every time.

I know there is a long list of potentials for this problem, but figured I'd start with easy and obvious and work down from there.

I plan to replace external voltage regulator first. If that doesn't solve it, any thoughts on the internal regulator, alternator, ignition switch?

As I said, other than some hard starts when the engine is hot (which I know is not all that uncommon), car has been running great, so I don't believe it will be a more ambiitious issue, as I've read on some other posts regarding hard starts.

Thanks in advance for any advice

Octania

Sounds like a defective battery or poor connections/ cables

Start reading voltages, beginning at the battery posts, with nothing on, then while attempting to crank.

Feel for hot connections after attempted cranking. Or successful cranking.

m371961

I agree with Octania, but disagree with your statement that hard hot starts are not uncommon. Often a hard hot start is the beginning of a start problem. Check, clean and tighten all connections to the cables. Do not just start replacing parts without checking volts at battery, then between starter cable and starter housing. While key is off and when starting.
Unless you have unlimited funding. Then do what the government does and throw money at your problem until it goes away.
Oh, and you should not have a external AND internal regulator.

Sugar Bear

Generator light staying on is a defective diode in the alternator. The battery is probably not getting charged properly. Test the alternator for voltage and amperage output. Have the battery load tested. Also check clean and tighten all connections as suggested.

droldsmorland

GROUNDS GROUNDS GROUNDS! As well as verifying the entire charging/starting system is within spec. Load test the Battery and alternator. And clean all the connections in the system. Ohm out the cables too, should be very low. Visually cables can look OK yet have high resistance due to age and corrosion.
Surface and load test the battery.
Load test the alternator. Is the alternator internally or externally regulated?
Load test the starter.

If you have the external VR there are specific ways to test and adjust and test that. (Ask or Google)
The generator light will illuminate for several reasons. Slipping belt, bad bridge diode, over or under charge, or just a bad Alternator(Stator/rotor Windings).

Author Harvey White:
Let’s check and find the problem. First, for a stock car, the original alternator should be more than sufficient and have no problem keeping up with the lights and heater fan. First, charge the battery, then disconnect the charger, verify that the voltage on the battery is 13.2 Volts or higher (it should read high due to the surface charge). Now turn the headlights on for 60 seconds. Turn the lights off and check the battery, it should read 12.6 Volts or higher, if not, the battery is weak. Now start the car. Measure the voltage across the battery, if it is not 13.8 Volts or higher, the alternator is not working correctly. If this passes, turn the headlights on. The alternator should be able to maintain 13.5 or higher, even with the lights on and the engine at idle. If the Alternator is not passing these tests, carefully measure the voltage at the rear of the alternator, across the battery terminal and the alternator case with the engine running and the headlights on. If this voltage is within 0.1 Volts of what you were reading at the battery, then either the alternator or regulator is bad. If this voltage reads higher, you have a high resistance path between the alternator and the battery. To find what side is bad (power or ground) begin by measuring the voltage between the alternator case and the battery negative terminal. The voltage should be 0.1 Volts or less, if not, you have a bad ground. Next, check the voltage between the battery post on the alternator and the battery positive terminal. Same as before, if the voltage reading is more than 0.1 Volts, check the wiring between the alternator and the battery. Before you put the Volt meter up, with the engine still running and the headlights on, measure the voltage from the regulator case (use one of the mounting bolts) and the battery negative. Again, the voltage should be 0.1 volts or less. If not, check the ground from the rear of the engine block that connects to the body. Finally, if the alternator failed the test, turn the engine off and attempt to rotate the alternator pulley by turning the fan. You should not be able to rotate the alternator without the engine turning as well, if not, your belt is loose or glazed and this will result in poor alternator output.

Ref 442 dot com, Harvey White.

oldcutlass

If the radio reset, I be inclined to agree with Octania. The battery connections are probably dirty. That's where I would start.

quaddriver

While I agree that all paths electrical should be verified before buying any hard parts, I have seen things SIMILAR to this when the starter is just going south.

Case in point, I had done a restore of an 86 estate wagon with the stone in it and it developed a hard start to the point I thought "well heckfire, nothing a new battery cannot solve" so off to walmart I went. No change. I started thinking that perhaps something was leaking and it was hydrolocking or worse. When I would start it the lights would dim like the battery was gone, acted dead.

BUT, I had a 75 D car with a 350 in it beside the shop so I took that starter off, installed it, and vroom. I have recently seen the same performance from a 5.0 Ford and a Mistubishi diesel tractor - in all 3 instances it was in the starter windings/brushes

quaddriver

PS, when I got this regency, both advance and autozone machines said it was a good and wonderful alternator using the test machine. When in fact, the alternator produced bad voltage and the gen light was on dim. So I dunno what criteria their machines use to say yay or nay, but it dont work...

droldsmorland

Stay out of those big box houses of chineasium junk. Thats likely where the test machine came from too and the directions to run it. Find a good starter alternator rebuild house in your area and have both tested there. After you've verified the simple items mentioned above.

stellar

I doubt if the equipment is to blame. More likely operator error.

quaddriver

my local starter/alt rebuild shop went belly up because everyone started going to the houses of 'chineasium junk'

quaddriver

I went behind the counter both times and while the machines were at the very least packaged differently (for all I know exactly the same underneath) he(s) did hook it up according to the plasticoated instructions and the gauges and lights did do things and it spat out a report. I specifically asked if it would detect a reverse conducting diode and while neither ute could answer, one mgr chimed in yes it could. and they dont do load tests, the older stuff used to use carbon filament arrays to sink a few amps and get a better picture.

voodoo I think and it proved to be wrong, I was going to get a kit from rockauto and do it myself but rock auto had a deal on 3 year warranty 63ampers that smelled of a better deal

droldsmorland

Shame on everyone for purchasing chineasium. Thats why I always support the mom n pop shops.