Won't Start When Hot!

Hi,Just wondering if any one else had this problem,I got a 73 vert.with a 351cj and when it gets hot it won't start.it's got a protronix 1281 & #40001 coil and a ballast restor.cold it will start right up!any ideas where to start will be greatly appreciated! Thank's Rick:

Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up? I have had trouble with pertronics dizzy's before and ended up being the ECM.

Hi,Just wondering if any one else had this problem,I got a 73 vert.with a 351cj and when it gets hot it won't start.it's got a protronix 1281 & #40001 coil and a ballast restor.cold it will start right up!any ideas where to start will be greatly appreciated! Thank's Rick:

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Rick, not sure about in your case but mine was a result of fuel percolation issues. I put a heat unsulater spacer under the carb and that took care of most of the problem. It would then start but take longer to start when hot than cold, my recenlty installed stainless steel fuel line runs right over my water pump (touches it) and drivers side head so for the heck of it I put a heat insulator sleeve over the entire line near the engine and that took care of the remaining heat issues, now starts right up no matter how warm. Probably over kill but I also put a heat insulater pad underneath my coil since I believe heat's what killed my last coil.

Jim

Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up?


Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up? I have had some trouble with pertronics dizzy's before and ended up being the ECM

Click to expand...

No,it turns over like it should,just put brand new coil,& rebuilt carb,let the car sit a couple hrs. an she starts she runs rough but I assume its from to much gas from trying to start it! I don't under stand the ballast resistor?Protronix said to get rid of it!But I don't know if the resistor wire was bypassed or not?

Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up?


Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up? I have had some trouble with pertronics dizzy's before and ended up being the ECM

Click to expand...

No,it turns over like it should,just put brand new coil,& rebuilt carb,let the car sit a couple hrs. an she starts she runs rough but I assume its from to much gas from trying to start it! I don't under stand the ballast resistor?Protronix said to get rid of it!But I don't know if the resistor wire was bypassed or not?

Click to expand...

aww sounds like spark issues..Usualy hot coil does that.

Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up?


Does it turn over real slow with maybe a kick back? if so timing is advanced too far. if she turns normal could be the coil. Is the carb loading up? I have had some trouble with pertronics dizzy's before and ended up being the ECM

Click to expand...

No,it turns over like it should,just put brand new coil,& rebuilt carb,let the car sit a couple hrs. an she starts she runs rough but I assume its from to much gas from trying to start it! I don't under stand the ballast resistor?Protronix said to get rid of it!But I don't know if the resistor wire was bypassed or not?

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the ignition does not need a resistor so you will need to bypass it.

If it cranks normal and won't start, I would look to vapor lock as the culprit. Wood or phenolic spacers under the carb really help with this.

As to the voltage, do you have a meter where you can turn on the ignition and check the voltage to the coil?

Points ran on reduced voltage to keep from burning them up. Pertronix doesn't need that "protection" and when running less than the nominal 12 volts, the electronics in the pertronics will burn up.

If it cranks normal and won't start, I would look to vapor lock as the culprit. Wood or phenolic spacers under the carb really help with this.

As to the voltage, do you have a meter where you can turn on the ignition and check the voltage to the coil?

Points ran on reduced voltage to keep from burning them up. Pertronix doesn't need that "protection" and when running less than the nominal 12 volts, the electronics in the pertronics will burn up.

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you can test this theory by running a wire from battery to a toggle then to ignition system. It's a cheap way to be sure and not a lot of work...but don't leave it that way...lol

reduced voltage leads to increased heat in a circuit IIRC but electronics is not my forte

Lots of prior discussions on by passing the resistor wire for a full 12V when using the Pertronix ignitor, "my take away" from the discussions is that the first generation Petronix is fine running on the resistor wire but the Pertronix ll and lll's need the full 12 Volts.

Running both a resistor wire and a ballast resistor coil increases the resistance. When these units get hot, there's not enough voltage getting through to run the Pertronix. Typically, though, with this problem, the car will run for some time and then die suddenly, and you'll have to wait some time for everything to cool down. If you run short periods of time and shut down the engine, there is a "heat soak" effect because nothing is being cooled, so for several minutes, everything under the hood gets even warmer.

There's a test I can tell you about to see if you do have a resistor wire or not. I believe, though, you'll have to replace the coil with a standard Ford coil, but it doesn't require running the engine.

Hi,Thanks yes I would like to try that test! I just bought the car so I'm not sure what some body else has done to the car!it's real embarassing when people walk by and say wow nice car and it won't start!

Sounds like advance and maybe a carb issue as well.

Might want to check your advance and see if it is holding vacuum(if it is vacuum). Or if is mechanical, check the springs and see if they are worn and need to be replaced.

What is your timing set at now?

What kind of carb and was it out of the box reman or did someone rebuild it?

Sounds like advance and maybe a carb issue as well.

Might want to check your advance and see if it is holding vacuum(if it is vacuum). Or if is mechanical, check the springs and see if they are worn and need to be replaced.

What is your timing set at now?

What kind of carb and was it out of the box reman or did someone rebuild it?

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Not sure what the timing is at I will check but just trying to get an idea as to where to start with this problem!The car is all stock except the protronix.an I just rebuilt the carb being a 4300D I thought i'd give it a shot if it don't work I'll have to replace carb & intake.But I think it's a electrical problem because when it won't start you can smell gas!

Hi,Thanks yes I would like to try that test! I just bought the car so I'm not sure what some body else has done to the car!it's real embarassing when people walk by and say wow nice car and it won't start!

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Send me a Private Message or an e-mail and I'll give you the specifics.

I just rebuilt the carb being a 4300D I thought i'd give it a shot if it don't work I'll have to replace carb & intake.But I think it's a electrical problem because when it won't start you can smell gas!

If you are cranking the engine over, but don't touch the gas pedal, do you still smell gas?

When it's hot, have you tried putting the pedal all the way to the floor and holding it there, then cranking the engine and trying to start it? If it starts this way, then it is getting flooded.

If it only doe sthis when it is hot, then this would tell you that the carb is ok, otherwise it would act the same way hot or cold. May atleast eliminate the carb chasing and point you back towards ignition.