Surge at idle when warmed up.

Justin@DP-Tuner · Jul 31, 2011

Hey guys,

I have been having a small issue. When I first start my truck up in the morning it fires right up and idles fine, but as soon as it gets to operating temp it starts to surge(550-650rpm) and shake(very little) when at a stop sign/light. The small shake is always in sequence. It isn't random. It does this weather I am in park or in gear. It also takes an extra crank to start if it is warm. I have been thinking IPR, but just want to get some opinions on it first. I know with the knowledge here I will get it figured out. I have no SES light either.

Thanks in advance.

Justin@DP-Tuner · Jul 31, 2011

Anyone have any opinions on this?

SIX_OHH · Jul 31, 2011

My 2004 engine did this. Never found the cause for it. I always thought it to be fuel related.

Arisley · Jul 31, 2011

How long since an oil change?

dmd · Jul 31, 2011

CPS acts up only when warm, but this doesnt really sound like that. I think you can
unplug the IPR for testing and the truck will still run.

Justin@DP-Tuner · Jul 31, 2011

Arisley said:
How long since an oil change?

Changed the oil 200 miles ago. I use Delo 400 15W40.

Justin@DP-Tuner · Jul 31, 2011

dmd said:
CPS acts up only when warm, but this doesnt really sound like that. I think you can
unplug the IPR for testing and the truck will still run.

CPS was replaced a couple of years ago. This feels nothing like it did when the CPS went out. The damn engine did whatever it wanted when that went out lol. Would run for 15 minutes, shut off, start right back up, run for 3 minutes, shut off and wouldn't start. This is just an example, it wasn't literally in that sequence.

Justin@DP-Tuner · Jul 31, 2011

Smut said:
My 2004 engine did this. Never found the cause for it. I always thought it to be fuel related.

Yeah, I'm not sure if it could be the same problem between 6.0 and 7.3.

Justin@DP-Tuner · Jul 31, 2011

I just put the AE on it. Cylinder contribution passed, everything looks normal. It did have 2 hidden codes though. It had P0476 and P0603. To my understanding the P0603 is from having the tuner, and P0476 is something to do with exhaust.

neverkickn · Jul 31, 2011

p0476 is probably from the ebpv being unplugged or faulty. My truck surges like that at idle but not near as dramatic as yours. It is barely noticable on mine. Does yours get real lopey for a second after you let out of the throttle?

dmd · Jul 31, 2011

Some have mentioned that if the EBPV tube to the sensor is plugged the truck
will act funny at idle. Have you checked the tube to see if it is plugged
with soot?

Justin@DP-Tuner · Jul 31, 2011

neverkickn said:
p0476 is probably from the ebpv being unplugged or faulty. My truck surges like that at idle but not near as dramatic as yours. It is barely noticable on mine. Does yours get real lopey for a second after you let out of the throttle?

Not extremely lopey, but yes a little.

Justin@DP-Tuner · Jul 31, 2011

dmd said:
Some have mentioned that if the EBPV tube to the sensor is plugged the truck
will act funny at idle. Have you checked the tube to see if it is plugged
with soot?

Haven't checked that yet.

Arisley · Aug 1, 2011

My truck will idle like that if I come off a hard run on the freeway and have to stop on the onramp.

neverkickn · Aug 1, 2011

Arisley said:
My truck will idle like that if I come off a hard run on the freeway and have to stop on the onramp.

mine does it almost everytime I let out of the throttle. Even when I have been putting along at low rpm.

Justin@DP-Tuner · Aug 1, 2011

Arisley said:
My truck will idle like that if I come off a hard run on the freeway and have to stop on the onramp.

Yeah, I would say that is normal. But mine will do it just sitting in park. Do you know where a good write up can be found to delete the EBPV?

Justin@DP-Tuner · Aug 1, 2011

neverkickn said:
mine does it almost everytime I let out of the throttle. Even when I have been putting along at low rpm.

Mine doesn't quite do that. I can only feel/hear it when I am stopped.

Justin@DP-Tuner · Aug 2, 2011

Well as I was installing my boost pressure sensor for my new gauge last night I noticed that my ICP was leaking oil. I am not sure if this could cause the surging problem, but I sure know where the oil on the bottom of the engine and trans bell housing is from now lol. Anyone know about the EBPV delete write up/video?

revolvingsteel · Aug 2, 2011

mine does it almost everytime I let out of the throttle. Even when I have been putting along at low rpm.

Mine will do this every now and then, what causes this? Is something wrong when this happens?

OP, my truck also has an occasional "hiccup" during idle. However, it doesn't sound like it is as noticeable as yours. Any help? Bump!

Justin@DP-Tuner · Aug 2, 2011

revolvingsteel said:
Mine will do this every now and then, what causes this? Is something wrong when this happens?

OP, my truck also has an occasional "hiccup" during idle. However, it doesn't sound like it is as noticable as yours. Any help? Bump!

Mine is only really noticeable to me. Everyone else just says don't worry about it, but I am very meticulous about how it runs because I want it to last a long time. Thanks for the bump. Hopefully someone will jump in here with some more ideas.