512 stroker starts but wont stay running

[bullet18]

Are both brown and blue hooked up? There is a split second from when you let off the start to run there is now power to ignition. with out the ballast resistor connection it will die. I understand It's an HEI .

Brown is not hooked up, so i need it hooked up?

 

[Challenger RTA]

That's what I'm wounding? Look at the diagram I posted above. the blue and brown wire feed power to the coil. brown wire in the start position feeds full power to the coil and the blue wire feed power to the coil through resistor at a reduced voltage. That's why I'm asking about the HEI wiring instruction. It could be you have a bad ignition switch.

 

[bullet18]

That's what I'm wounding? Look at the diagram I posted above. the blue and brown wire feed power to the coil. brown wire in the start position feeds full power to the coil and the blue wire feed power to the coil through resistor at a reduced voltage. That's why I'm asking about the HEI wiring instruction.

Lemme look for them. They may have gotten lost over the years. I built this motor then it sat for a while. I just primed it at started working on it again.

 

[pschlosser]

FYI, by proposing it's fuel-related, I'm referring to all things fuel related, fuel pressure, delivery, mixture, etc. I believe you said it starts at the fender well, then dies 1-3 seconds later, is that still correct? If so, I think your electrical and ignition are fine.

I presume you are NOT filling the fuel bowls more than one time, am I right? Just the one time? The fuel pump will keep the bowls filled, unless it cant get the fuel there.

Is that carb brand new, or was it used and sat for a while? Has the carb ever run well on this (or any) engine?

Is it choked when starting? Does it stay choked when running? A choke pull-off may open it up too soon and cause the engine to die as soon as it makes vacuum. I'm not sure how your choke will behave, though.

Too bad you don't have an alternate running OEM carb you could throw on there for testing.

 

[bullet18]

That's what I'm wounding? Look at the diagram I posted above. the blue and brown wire feed power to the coil. brown wire in the start position feeds full power to the coil and the blue wire feed power to the coil through resistor at a reduced voltage. That's why I'm asking about the HEI wiring instruction. It could be you have a bad ignition switch.

It is wired up correctly, it cant be the problem cause when i bypass everything and just put it in run and short the starter i have spark and it fires but doesnt stay running.

 

[pschlosser]

Looking at your engine photo, I dont see a vacuum choke pull off, so maybe this isn't it. Using your phone to make a video looking down into the throat of your carb, showing your start-run attempt, may show the choke opening as soon as it runs and causing it to die.

 

[bullet18]

FYI, by proposing it's fuel-related, I'm referring to all things fuel related, fuel pressure, delivery, mixture, etc. I believe you said it starts at the fender well, then dies 1-3 seconds later, is that still correct? If so, I think your electrical and ignition are fine.

I presume you are NOT filling the fuel bowls more than one time, am I right? Just the one time? The fuel pump will keep the bowls filled, unless it cant get the fuel there.

Is that carb brand new, or was it used and sat for a while? Has the carb ever run well on this (or any) engine?

Is it choked when starting? Does it stay choked when running? A choke pull-off may open it up too soon and cause the engine to die as soon as it makes vacuum. I'm not sure how your choke will behave, though.

Too bad you don't have an alternate running OEM carb you could throw on there for testing.

Its a brand new edelbrock avs2 that has sat for a while. Ive never got it to run on anything but i only have the one car it would fit on.

 

[bullet18]

Looking at your engine photo, I dont see a vacuum choke pull off, so maybe this isn't it. Using your phone to make a video looking down into the throat of your carb, showing your start-run attempt, may show the choke opening as soon as it runs and causing it to die.

Its an e choke and its unplugged so it doesnt just open and stay open after one failed start attempt.

 

[pschlosser]

If the (disconnected) electric choke it's not already in its choke position, i recommend adjusting it so it chokes the motor. Later, when you get the motor running, you can adjust it better when reconnecting it electrically. If you've got a longish-duration cam in there, you may need that choke choking.

 

[bullet18]

If the (disconnected) electric choke it's not already in its choke position, i recommend adjusting it so it chokes the motor. Later, when you get the motor running, you can adjust it better when reconnecting it electrically. If you've got a longish-duration cam in there, you may need that choke choking.

Ive got a pretty big cam in it. The choke is definitely closed rn though.

 

[Challenger RTA]

AS tonysrt said.
If it dies when you release the start part of ignition key, put 12 volts right to the + side of the coil and if it continues to run ignition sw is not giving volt to ignition system in the run position. Only do this to see if it runs for a short period of time or you'll wipe out coil. If you had problem before could still be a weak pump. Check ignition as above and then go from there.
We where all there at some time.
Symptoms of of a bad ballast resistor or ignition switch or wires.
Your getting fuel it's in your oil.

 

[pschlosser]

With full fuel bowls, but without additional fuel, I recall an OEM 440 carburetor will start a 440 and cold idle at 1500 RPM for 10-20 seconds before it dies.

If in your testing, your getting 20 seconds of total run time, but you don't have to refill your float bowls, it may be safe to conclude your electric fuel pump and filters are flowing just fine.

 

[bullet18]

With full fuel bowls, but without additional fuel, I recall an OEM 440 carburetor will start a 440 and cold idle at 1500 RPM for 10-20 seconds before it dies.

If in your testing, your getting 20 seconds of total run time, but you don't have to refill your float bowls, it may be safe to conclude your electric fuel pump and filters are flowing just fine.

I cant get it to run that long only like 2 to 3 seconds.

 

[pschlosser]

I mean total run time 20 seconds. By the time you've run it 10 times at 2-3 seconds each time, if the bowls are still full, then your fuel delivery to the carb may be fine.

My troubleshooting brain won't turn off.

In my mind, I have a list of which subsystems are proven working and tested, and which ones are not.

 

[bullet18]

I mean total run time 20 seconds. By the time you've run it 10 times at 2-3 seconds each time, if the bowls are still full, then your fuel delivery to the carb may be fine.

Ok. Will do. I think fuel delivery to the carb is fine cause fuel pours out of the line and carb fuel inlet when i disconnect the hose.

 

[pschlosser]

Gosh, it sure is smelling more and more like fuel mixture is the issue. The carb should function fine without connection to the distributor and crankcase.

I would disconnect AND plug (to carb) the vacuum and PCV lines, so they don't leak any vacuum, and try again.

I've plugged lines for a quick test using vise grips to pinch the lines in place.

 

[Challenger RTA]

Found this on A bodies only. HEI conversion help Looks like the brown and blue are splice together. Read before you do it. My concern was the internal connections of the ign sw would it keep the started engaged.
I'm thinking in the HEI kit there was a jumper wire to bypass the resistor.

 

[bullet18]

Gosh, it sure is smelling more and more like fuel mixture is the issue. The carb should function fine without connection to the distributor and crankcase.

I would disconnect AND plug (to carb) the vacuum and PCV lines, so they don't leak any vacuum, and try again.

I've plugged lines for a quick test using vise grips to pinch the lines in place.

Well, just shot gas out of the carb and had a small fire ball. Maybe i need to recheck timing? Im probably gonna do that tomorrow when my friend is here to help. I plugged the vacuum lines and that seemed to help a little. Its a little more eager to start.

 

[pschlosser]

A backfire through the carb? A lean mixture caused by vacuum loss can cause this. So can applying throttle to a cold and poorly choked engine. Same fuel mixture result: too lean?

If the timing were way, way off, it would run really rough (if at all). If you want a sanity check, manually turn the engine to TDC (top dead center) and pull the distributor cap. The rotor should be pointing at cylinder #1 plug wire.

I'm guessing your timing isn't way, way off, or you would not be running for those 2 seconds. Also I don't believe a timing issue can really change the fuel mixture.

 

[bullet18]

A backfire through the carb? A lean mixture caused by vacuum loss can cause this. So can applying throttle to a cold and poorly choked engine. Same fuel mixture result: too lean?

If the timing were way, way off, it would run really rough (if at all). If you want a sanity check, manually turn the engine to TDC (top dead center) and pull the distributor cap. The rotor should be pointing at cylinder #1 plug wire.

I'm guessing your timing isn't way, way off, or you would not be running for those 2 seconds. Also I don't believe a timing issue can really change the fuel mixture

I guess ill try fattening up the mixture.