Technical SBC..starts, stops, starts up? ? ?

My SBC with a HEI dizzy starts right up, runs a few seconds, and then dies, and then I hit the key and it fires right up, runs and quits. I checked and there is plenty of fuel in the carb when it quits, so it must be something electrical right? I more of a points & condenser guy sooooo any input will be greatly appreciated.....

 

Is this something you're just putting together, or has it been running all along and this suddenly started?

 

My guess is the fuel. You got spark. Maybe not the correct amount of fuel, too much OR not enough.

 

Seems that you're not keeping voltage on the coil, or it's dropping...as mentioned above (assuming carb is good, timing, etc) was this a recent conversion?..I kinda thing the older starter solenoids used in points systems switched over when key was on run, and allowed the coil voltage through the ballast resistor, I think the HEI's don't need the ballast resistor..and also, I think you might need a larger than stock wire gauge to feed the coil as well.

Just some thoughts.

 

That's what I was thinking Budget....loss of power when dropping back to the run position. If it just happened, that's where my money is.

 

Check the pickup coil for a broken wire. Sometimes when the vacuum advance kicks in the ignition can cutout if there's a break in the wire.

 

Bet you a 6 pack of beer it's the HEI MODUAL .

 

sounds to me you are getting power to the distributor while the ignition switch is in the start position but not when in the run position

 

There pretty much bullet proof,but mine was the pick up coil
Please let us know what you find.

 

Thanx for the input, but this is not a new install, and the fuel is fresh, and had been running great, just been sitting for a couple of weeks...any other ideas?

 

I've had this happen to me, personally twice. Both times it was the HEI module.

 

Does it have a ballast resister? if so put a wire on both terminals and try it. JW

 

I don't know what year car your SBC is in but I had a 57 Chevy that had a bad ignition switch. I would be driving and it would act like the engine had a mind of it's own. On, off, on, off. It took some time to T/S but the switch fixed it.

 

If its a GM HEI aside from being a junk distributor it runs on 12 volts.

It sounds to me like a problem with the distributer, I could be wrong it could be the ignition switch or any number of other gremlins, I would borrow a distributer before I started throwing money at it and see where you end up.

 

went thru something similar with my sbc and hei. turns out the hei coil was bad. after talking to hei techs thru summit, jegs and speedway, I traced it down to that. they said if the module was bad it would not start at all. but the coil can work then not work.
think they run about $40 ish to exchange depending on brand.
I'm a points guy too, this was a little lesson
hope this helps

 

I agree they don't look traditional- but GM did put several million of them into service

I'd say change out the module and see why happens

 

I had a '76 Chevy Monza V-8 do that. It was the ignition switch on the lower end of the tilt column. I burned up a couple of switches before I got it figured out that it was out of adjustment with the long rod that goes up to the key tumbler.

I also had a number of ign. modules die on me. They'd just quit, no off and on again.

Let us know what you find, so all of us cyber-mechanics can sleep at night! lol

 

If the primary wire to the distributor does not have a proper HEI connector with the clip that holds it on the cap and has a female slide connector on it the trouble might be right there. It has loosened up to the point where while it makes contact to start the engine the vibration of the engine or the vibration of driving breaks contact enough that the engine quits. The one on my ot truck managed to come loose every time it rained when I was on my way to work at 4 am.

Usually modules work or don't work with little in between.

I had it proven to me a few years ago that the leads on the pickup coil can give out from flexing when the advance moves the distributor plate many thousands of times and one lead or the other may not make contact when the distributor advances a bit.

It's been covered hundreds of times but HEI distributors do not work correctly if a resistor is in the system be it a ballast resistor on the firewall or a resistor wire the distributor. There are still guys out there who stick a resistor in the system though because they "always" had a resistor on their rig.

 

make a temporary 10 gauge jumper about 6 feet long with spring clips on the ends. Attach one end to a switched 12 volt source,the other to the batt. terminal on the HEI. Try starting with the switch.If it runs,,your distributor is good.If the problem persists ,you have a switch or starter circuit problem.

 

1. If you are going to run points you will need a dwell meter.
2. I recommend an HEI system
3. You need to by pass the ignition resistor as this device is designed to reduce voltage to the points and extend their life.
4. Build that jumper wire and hook it to the big terminal on you alternator and battery terminal on your HEI.
5. Fire it up and if the problem goes away you know what's going on.
6. If you still have the problem pull the modual out of the HEI and take it to OReillys to test. Make sure they test it 6 times.
7. Don't buy a cheap modual it will fail.
Good luck

 

Had same problem with women on dates. Increase fuel mixture until warm.

To verify that it is electrical, you could pull a plug and ground it, then watch to see if spark goes out before engine stops.

Had that happen on dates too. Replace date.

 

Putting them in hundreds of thousands of vehicles (not millions) does not make them a good distributer. To start with they are a smog era distributer and if you want to get decent performance out of them you change to an after market module as well as re-curve them. They run hot and burn coils which is why the after market guys like say mallory and MSD made an external coil conversion for them, they also have a tendency to burn pickup coils as well as control mods.

I personally don't have a problem with the looks of one, if they worked good looks would be secondary to me. I don't just throw out bullshit about something because I don't like it. if I say that something is crap I got good reason to say that.

 

I modified a tach drive points distributor many moons ago with HEI stuff, and mounted the module outside with heat sinks (by the dip stick) and an external coil. Still working fine but I seldom drive the mighty BBC now that I have a flatty.

 

I agree 100%, been there, done that. Female slide connector may look like it's on, but will actually not be making much of a connection causing said problem. Easy fix is to get a GM style plug with the locking clip, problem usually solved......

 

I know this is years latter but my 283 w/HEI is doing the same thing and I wanted to know how U fixed yours please. TY J