ocsurf16

Its starting to get cold here up east and I was just up in VT for the week. I started the truck and it began to surge then go into high idle about 1100 RPM. I understand the highidle thing goin on but the surging? It almost sounds like my mustang with lopey cams in it...whats the deal? IS it bad?
By the way I have the Pred Programmer level 2

Luvnacumns

I don't know about the 04.5's but the 06 have a warm up cycle and they will surge until the truck is warm.. If you watch the amp guage it will surge from 8 amps to 14 and back and forth..

Shane

4x4onTheSho

I know what you're talking about. It reminded me of the 88 monte carlo I owned when the choke was on and hadn't brought itself down yet. Like it's choking for fuel. I was told by a Cummins diesel mech. friend of mine that it's because the Cummins have larger cylinders than the other diesels (6 vs 8 cyl) and it takes a lot of pressure/fuel to get er going in the cold. Mine did it tonight actually (after not starting 3 times in a row after glo plugging) but I just bought a block heater cord so I'm hoping it'll stop. Hopefully someone else with more info will chime in.

TurboTed

It's the grid heaters working. Causes rpm's to drop, lights to dim, and the quick surge you hear. It'll do it over and over when it's cold out, and the truck hasn't been warmed up.

ZacHolley

i think what he is talkin about is when you dont touch anything for a few minutes with really cold weather it almost sounds like a low RPM rev limiter. and i believe its normal mine always does it after few mins then i tap the break and it slowly revs back down from 1k-1100

TurboTed

Yep- normal- grid heaters.