Misfire Under Load

[Danr55]

Have you done a compression test on the motor?

[patrickt]

Yeah, maybe start out really simple by just disconnecting the PCV and put in a fresh set of plugs, forget the carb switch for now. That's a lot of oil going somewhere and, if you're really lucky, you've just got a big glob of it coming in the base of the carb through the PCV, then it hits the plugs, causes a misfire, then it burns it all off, scares the people behind you that you're on fire or something, and then it runs good for a while before it does it again. Maybe.

[Spyglass]

Originally Posted by patrickt

Yeah, maybe start out really simple by just disconnecting the PCV and put in a fresh set of plugs, forget the carb switch for now. That's a lot of oil going somewhere and, if you're really lucky, you've just got a big glob of it coming in the base of the carb through the PCV, then it hits the plugs, causes a misfire, then it burns it all off, scares the people behind you that you're on fire or something, and then it runs good for a while before it does it again. Maybe.

Assume I should leave the PCV in place and route the pipe from the PCV to a temporary puke bottle to catch any oil?

[patrickt]

Originally Posted by Spyglass

Assume I should leave the PCV in place and route the pipe from the PCV to a temporary puke bottle to catch any oil?

Don't get fancy, just pull it and plug it. If you built up that much crankcase pressure you'd be shooting your dipstick up through the hood.

[Spyglass]

Originally Posted by Danr55

Have you done a compression test on the motor?

Unfortunately I don't have a compression tester but would like to get this checked as this would give me indication regarding piston ring condition(s). That's why I'd like a recommendation for a good classic ford engine shop in Houston.

[LG57]

I can't say how good they are, but Bumberra's is in old town Katy and is a performance shop with a dyno and has been in business for quite a while.
I have a dyno sheet for my car done by them for a previous owner and the tuneup has been good.

[Spyglass]

Originally Posted by LG57

I can't say how good they are, but Bumberra's is in old town Katy and is a performance shop with a dyno and has been in business for quite a while.
I have a dyno sheet for my car done by them for a previous owner and the tuneup has been good.

Thanks, I’ll check them out

[jhv48]

If all 8 plugs look like the one in the picture, then you’ve got a set of fouled spark plugs. The blue smoke seems to point to oil fouling, but could be fuel too. Not going to run right until you either clean them or replace them. Are you sure they’re the right heat range for your engine?
It’s rare to see all 8 oil fouled at the same time because of a head gasket or intake gasket leak. rarely do both head gaskets or intake gaskets leak into all eight cylinders.

Those plugs will never run right in the shape they’re in. Replace them and then go for a ride.

You indicate that the engine runs better after two or three acceleration runs. That indicates that the combustion is trying to clean up the fouled plugs.

Have you noticed a decrease in your mileage recently?

Do you have an automatic choke on the carb? Is it fully open?

Do you only run a few miles each time you drive or do you get it up to temp and let it stretch it’s legs?

My suggestion is to replace the plugs and take it out on a twenty mile drive. Get it good and hot. Not stop and go driving. Freeway or mountain roads. Let it run and see if the problem goes away. Hard to diagnose if the oil is being consumed or leaking out if there is lots of oil on your floor.