HELP! why is my engine doing this?!?

[Muddred12]

Hey guys, having problems any advice?

Having problems with my engine, when it gets to operating temp and is there for awhile 190. The engine under WOT completely cuts out for a very short amount of time (like 1 second) like a light switch. So WOT will run fine then cut out for a second then run fine then cut out for a second. I hit 1st thru 3rd WOT and it did it probably 6 times. I thought it was the coil so i replaced it and it didn't help. I changed the fuel line filter. I have a wideband o2 sensor and I'm not running lean or rich. Any thoughts or ideas? Also keep in mind when engine has NOT been at operating temp for a significant amount of time it never does this. *update, i have upgraded my fuel pump and next i will be putting a new pick up in.

 

[khryslerkid]

If you have an electronic distributor, it could be the module. A weak one will break down when running at operating temperature but run ok when cold.

 

[Ron H]

The cold running improvement could be related to the choke position assuming you have a carb system, and may not be opening properly under temp. Couple things to check easily would be vacuum (cold and hot motor) and to check fuel pressure...would say avoid hammering motor hard unless it's at operating temp.

 

[Muddred12]

The cold running improvement could be related to the choke position assuming you have a carb system, and may not be opening properly under temp. Couple things to check easily would be vacuum (cold and hot motor) and to check fuel pressure...would say avoid hammering motor hard unless it's at operating temp.

i dont have a choke on my carb. ill check fuel pressure, how do you check fuel pressure while driving? i meant when it just reaches operating temp it never cuts out but when ive been driving it for say 20 mins at operating temp it will cut out at WOT.

 

[PurpleBeeper]

vapor lock? Do you have any type of heat shield/spacer under the carburetor? When I had a motor with vapor lock it would barely run though until it cooled off.

 

[bigbluedodge]

What engine, carb, intake and ignition do you have?

 

[moper]

Pickup coil in the distributor. Potentially the module depending on what you have in it now.
But my money's on the pickup going bad. I've had V8s and 4cyls all suffer from that, and all did something like, or exactly what you are saying when they started to go.

 

[Muddred12]

What engine, carb, intake and ignition do you have?

Small block 392, eddie 650 cfm, eddie rpm air gap, pertronix ignitor iii

 

[Muddred12]

Pickup coil in the distributor. Potentially the module depending on what you have in it now.
But my money's on the pickup going bad. I've had V8s and 4cyls all suffer from that, and all did something like, or exactly what you are saying when they started to go.

Pertronix ignitor iii

 

[Muddred12]

vapor lock? Do you have any type of heat shield/spacer under the carburetor? When I had a motor with vapor lock it would barely run though until it cooled off.

I dont think i could run one and my hood be able to close. My intake is tall.

 

[moper]

Pertronix ignitor iii

It's still the problem.

 

[Muddred12]

It's still the problem.

Not what I wanted to hear!

 

[64 Post]

What coil with the pertronix? What resistance? Oil or epoxy filled?

 

[Muddred12]

What coil with the pertronix? What resistance? Oil or epoxy filled?

Pertronix Flame thrower iii, oil filled. .32 primary resistance