A funny thing happend yesterday while waiting for my wife to come out from Christmas shoppin. . . my checkin' account was lighter.

No seriously, I was watchin' the tach with the three kids in the back,
the engine was stirring, and the heads were not cracked.
When what to my wandering eyes did appear,
a surge at idle, and I said "oh dear"
it went from 550 to 750 I do say,
I wonder if Santa has a 6.5 on his sleigh?

Okay, sorry, I'm a little lackin' in sleep right now,
I'm just wonderin will the answer be "holy cow!"

Enough of this poetry and comotion,
as long as my bus stays in motion.

Any thoughts? On the engine that is. . .

Thermostat(s) opened, allowing cold water from radiator to quickly lower engine coolant temps at idle - PCM kicked cold advance in.

Or, intermittent ECT sensor connection.

Or, holy cow!

Ain't touchin' the poetry, dude.............yer on yer own.;)

ECT connection, you may be on to something there. Temp reading on dash stays rock solid, no variation at all, or slow decline at long periods of idle time.

I asked tex about this once and he said all 6.5L will Idle up to 750-800 when APP signal hasn't been given. Throttle it down the raod and it disappears.

It's losing the APP signal now maybe you think? Would that throw a code, being that at least one or all three of the circuits is low? Did I read this right?

My ECT in the crossover last month started acting funny. It would start like normal and kick the idle up and then drop it back down like normal. But, if I would touch the throttle again it would kick it back to 800 rpm at idle until I shut the truck off or unpluged it under the hood and then it would drop back down. Drove it for a week like that unplugging it every morning until I could put in a new sensor, and now no more problems.

Mine does just the opposite. When I start mine, the rpms go way low and the engine wants to die unless I manually bring it up to 6 or 700rpms. Once I hold it there for a little while, it evens out at normal. Any Thoughts?

Thanks

your talking about a mechanical pump right? just need to tap the throttle to make the fast idle solenoid pick up, it doesn't have enough pull to pick up speed on its own.