Aloha. I have a 2001 ford E350 15 passenger van with a V10 I've noticed under load in high gear I get a slight miss once in a while. If I let off accelerator then it goes away. Or if I push in od button it doesn't do it. Just changed all sparkplugs using factory ford plugs. The problem existed before the change of plugs as well. Also no check engine light. Any suggestions?

 

This could be what's called a low-grade misfire, something that doesn't typically trigger the CEL. Connecting a good scanner that will read pending codes will sniff this out if it is indeed a misfire.

On a V10 the misfire seems to smooth out at higher RPM's but that's a bit deceptive---its only masked because its frequency and duration is less due the number of cylinders and the RPM's themselves. Cancelling OD effectively increases engine RPM's.

I'd double check each chassis wiring harness connector to the COP's, make sure they securely latch in place. Over time the locking tabs can break or fail to maintain good electrical contact.

You might have a slight vacuum issue too---the scanner might pick up a lean bank 1, lean bank 2 code. PCV valve or its 90* elbow at the throttle body could be an issue.

Hope this helps.

 

When my V10 did this it was a couple of coils that were getting weak. I replaced all 10 and the problem went away.