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RPM Surge at idle?

2K views 8 replies 5 participants last post by  kg208 
#1 ·
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?



Thanks


Keith
 
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#2 ·
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
 
#4 ·
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.
 
#5 ·
Mine is JUST like A64's. It also seems to get worse when trying not to hit an expensive vehicle like a Porsche.
 
#6 ·
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.

Edited by: hoot
 
#9 ·
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.
 
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