Misfire at high RPMs?

[KYEdge]

Twice now several weeks apart, when passing another vehicle I have had to get onto the gas a little more than normal, causing the truck to shift from OD and jump up to 4K+ RPMs. After a second or so the CEL has started flashing. Now it is my understanding that this is a misfire right? After dropping the RPMs the flashing has went away after another 30 seconds or so.

Never had *knock on wood* this problem at normal RPMs, just at the higher RPMs.

I doubt it is a compression problem, since it won't happen at the lower RPMs.

Bad spark plugs? Weak ignition coil?

 

[jhammel85]

Yeah you've got a severe misfire going on if it's blinking. Definitely, do not ride that out...It could damage something.

If I'm not mistaken, the high RPM misfire, if its your ignition, is most likely bad plugs. Wires, cap and rotor should also be taken care of.

How many miles are on the truck? 1st thing to do is to have it checked for codes, or check it yourself with a scanner. Try removing a plug and have a look at its condition.

 

[KYEdge]

118K on the truck.

I will look at the plugs when I get a chance.

 

[TomB1269]

FYI; high RPM mis-fire or bucking is also a sign on Syncronizer shaft failure. Does she squeal every morning? Try pulling the seprentine belt and start for a minute. If it squeals it the syncro shaft.

 

[KYEdge]

Nope no squeal.

For what its worth the fuel pump was just replaced.