Thread: Help! 350 small block got hot and turned off now wont start!

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I recently purchased a 1985 cutlass supreme wit a 350 small block. Dont really know too much about the engine except it being out of a 1972 corvette and Holly 4barrel carb, weiand intake manifold. I forgot to turn fans on omw home and pulling in the driveway i noticed the temp was up and car shut off at that same moment. I turned fans on so it can cool off a bit. left about hr and a half be for i tried to start it but no luck. The engine turns and oil is clean(Changed oil 3 days before). Sparkplugs are dry.(changed them while i checked them so they are new now.)Radiator full and engine blew no smoke. Also noticed my rpm gauge doesnt move when i try to start which it ussually does when i start it up. Engine was in pretty bad shape when i bought car a few weeks ago from sitting for over 3 years.

Rpm not working may be a clue. Possibly the ignition module died?
Check for spark.

Thinking the same, my tachometer is connected to the coil so it sounds like something in the coil/distributer/spark wires or ignition circuit. I would do the old take one spark plug wire off, and test to see if your getting spark. If not it narrows the problem considerably!
This auto meter schematic shows how tthe tachometer is connected the ignition circuit.
https://www.autometer.com/media/manual/2650-1244.pdf


I'm guessing if the engine turns over the ignition switch is o.k., maybe the other guys on here can be more specific. If you engine uses a points and condensor, then your problem could be there, or with one of the wires routed thru there. I nice multimeter can help check old wires for conductivity. On my 71 ford it did the same thing, no spark, I replaced everything, only to find it was the wire from the distributor from the coil. Matter of fact trying to figure this out was the first post I came to this site for, and Techinspector figured out my problem!

To test for spark the old fashion way, remove one wire from a spark plug, stuff a screw driver into the wire boot where the spark plug metal top fits into, lay the screw driver attached to the wire across a metal surface(on engine) that the spark can arc across(don't touch while testing and don't put near a flammable source(i.e. leaking carb on manifold). the engine is negative ground, if the spark plug is getting + juice from the coil, then where ever the metal shaft of the screw driver is touching say a unpainted manifold bolt you should see a park. If you have spark, then things get more interesting, if you don't the problem lies somewhere in the ignition/spark circuit. Have someone crank it over while you look for a spark. Others might have a safer way to do this, or different, this is just the "use what you got" method that we did in High school autoshop in the 70's.

The schematic I posted shows the tach wire going to the negative side of the coil, so like Firebird said above check the coil wires first!

Thanks to all. Will check soon as im home.

How hot did it get, i.e. were you driving at speed and pulled into the house, or were you in traffic, stop & go and for about how far? I assume it's an iron head engine if it's '72, and also that it's a point style distrubutor and not High Energy Ignition?

Point Style (coil mounted separate) -


HEI Style (coil on top of the cap) -

If nothing obvious shows up, take a digital photo of the engine showing coil and distributer, post it here if you can. This will narrow down what parts are on there.

Lift the distributor cap off,
Have someone turn the key (crank)

and see if the rotor spins. Also, see if there is oil pressure while cranking ( if gauge is available.)

Just trip to store nearby maybe 4 miles round trip. No traffic but made a few little trips before with no issues. Engine only got hot cause i didnt turn on fans since im still not used to the switch. Pulled into driveway and revd engine twice and it shut off. Then i noticed the water in resivour tank was boiling. Engine blew no smoke, oil is clean, no water or oil on sparkplugs, engine turns but to start.checked rotor in distributor cap and its spinning. Checked for sparks with flathead and touching many different parts of engine and i get no sparks at all. Gauges arent working right now. There all there but No voltage no oil pressure gauge no rpm gauge either.Pics are there. 2nd pic is when i bought the car 4 weeks ago and 3rd pic is now.

That might be a electronic ignition Distributor. Looks a lot like the one I'm using in my Ford,a mallory Unilite, that takes the points and coil out of the conversation I don't see a coil in the photos, and mine definately needs that, so maybe some others on here are seeing something I'm not, although there may be a red box behind the distributor on the right, just barely in view on the above photo. I'd trace the wires from the ignition switch to the distributor, I'm guessing they problem might be somewhere there. Hopefully one of the chevy guys will have a better idea.

No gauges puts a new spin on it. Check fuses.

Last time I had an issue with an HEI no spark, it was the coil in the cap gone dead. Usual trouble is the module; always keep one in the glove box.

I'll bet if you look for voltage into the dizzy, you'll find none.

Good luck!

Coil i believe is right under the top plate inbetween the spark plug wires which on the right side of the distributor it does have a little box with wires goin into it. Gauges arent working cause im pretty sure i killed my battery trying to get car started but rpm gauge gave out while others where working just fine.already checked all fuses and there good. Gotta charge it up today when i get home from work. I just hope it something simple. Thanks to all of you for the help.

So should i try changing module or coil or both?

Ok so i charged my battery and checked for spark again and it has spark. Gauges back online. Oil pressure of 20 while trying to start car, 12 volts fully carged battery. When i turn my key the rpm gauge does a slight movement but stays on zero and still Wont move at all while i try n get it started.