I have just started noticing a slight rpm surge while stopped in traffic, surges just enough to move the tach needle and you can hear & feel it. Never noticed it before truck is a 03 Dmax w/ 15K on it. Is this normal? http://dieselplace.com/forum/smileys/Confused.gif


Thanks


Keith

My truck did the same thing when I used the defroster. It doesn't seem to do it when I use the floor/vent position http://www.dieselplace.com/forum/smileys/Confused.gif

Does if with or without de-froster on. I think its getting worse.

A sticking RPCV "rail pressure control valve" is one cause of that. Mine is an early 01 and has done it since the beginning. There was a reflash for the old trucks, didn't help mine much. Used to have to change the fuel pump to fix it. I think they can now change the valve only. If it's a sticking RPCV then adding good fuel treatment should help calm it down. BTW mine is worst when cold, goes away when completly warmed up and the colder it get's the worse it get's.

Mine is JUST like A64's. It also seems to get worse when trying not to hit an expensive vehicle like a Porsche. http://www.dieselplace.com/forum/smileys/Geek.gif

I just had my RPCV replaced (along with head gaskets) last week. The new valve did the trick. Idles rock steady...

They get like 40 minutes to do the job (RPCV) so it's not very labor intensive.

It's that thing on top that looks like a miniature starter motor.

http://www.uscom.com/~hoot/cars/duramax/gmc/headgaskets/images/DSCN4574.jpgEdited by: hoot

Thanks Guys, We will see how good my local Chevy Dealer's Diesel Tech is, I have an Appointment for Thursday. The Dealership only has one Diesel Tech, Hope He's good.http://dieselplace.com/forum/smileys/Geek.gif





Keith

Hoot,


Why the head gaskets? What happened?

Got my truck back today, idle problem fixed, tech said that the fuel pressure regulator was binding. all fixed now. getting ready for my juice/ attidute combo now, gotta love income tax return season.