Possible ignition problems

[joseph.signore]

I have a 1991 5.7 350 magnum with thunderbolt ignition alpha one gen one:

I?m having power loss and then stalling issues when the motor gets to normal operating temperature. The engine runs fine after cooling and I suspect the problem is one of the ignition components. I see three but not sure what to start with that could be affected by heat. 1) Distributor pick-up. 2) Ignition amplifier box. 3) Ignition coil. I don?t know how to test any of these components and the motor runs fine sitting at the dock.

Thank you?

 

[Bondo]

Re: Possible ignition problems

I have a 1991 5.7 350 magnum with thunderbolt ignition alpha one gen one:

I’m having power loss and then stalling issues when the motor gets to normal operating temperature. The engine runs fine after cooling and I suspect the problem is one of the ignition components. I see three but not sure what to start with that could be affected by heat. 1) Distributor pick-up. 2) Ignition amplifier box. 3) Ignition coil. I don’t know how to test any of these components and the motor runs fine sitting at the dock.

Thank you…

Ayuh,.... Here ya go,....

 

[Don S]

Re: Possible ignition problems

That chart is for the Thunderbolt V, the OP has a Thunderbolt IV.

Here is that chart.

 

[joseph.signore]

Re: Possible ignition problems

Thank you both! But, now I?m thinking it?s a fuel problem. I tried to get the boat to repeat the symptoms so I could test the ignition today with no luck? (The engine ran perfect)

12 hours earlier running at normal operating temperature the boat was bogging, stalling?loss of power/no power no idle. The boat would run for 30 seconds and then stall.

I ran the boat at the dock for over an hour with no issues when just 12 hours earlier I was being towed back to the marina.

I?m stuck between fuel pump overheat fail or ignition coil overheat failure or possibly some kind of vapor lock in the fuel system. I did notice every time the boat stalled I heard some clicking noise coming from the fuel pump followed by a purging click coming from the fuel tank that stopped as soon as I removed the rubber input fuel line from the tank.

Any ideas?

 

[joseph.signore]

Re: Possible ignition problems

Thank you both! But, now I?m thinking it?s a fuel problem. I tried to get the boat to repeat the symptoms so I could test the ignition today with no luck? (The engine ran perfect)

12 hours earlier running at normal operating temperature the boat was bogging, stalling?loss of power/no power no idle. The boat would run for 30 seconds and then stall.

I ran the boat at the dock for over an hour with no issues when just 12 hours earlier I was being towed back to the marina.

I?m stuck between fuel pump overheat fail or ignition coil overheat failure or possibly some kind of vapor lock in the fuel system. I did notice every time the boat stalled I heard some clicking noise coming from the fuel pump followed by a purging click coming from the fuel tank that stopped as soon as I removed the rubber input fuel line from the tank.

Any ideas?

Could this be water in the fuel?

 

[achris]

Re: Possible ignition problems

Could be a blocked tank vent!!