LLY: 2006 GMC 3500 LLY idle jumping

Jncrawford18

Jncrawford18
Jun 22, 2019
31
0
0
NC
I have a 2006 GMC 3500 Duramax lly I bought it back in November bone stock haven't had any issues with it until now it has 183,000 miles on it I recently put a 5" magnaflow straight pipe exhaust and a 3" mbrp down pipe and a bully dog gt tuner on it I don't run it in the performance or extreme tune in the past couple of days it started jumping up in rpm's at idle in park I'm pretty mechanically inclined but I'm new to the whole diesel world any advice would be appreciated thanks
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,310
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Mid Michigan
Moved over to LBZ section. (06 LLY pretty much the same exc tuning)


Curious, could it be EGR related due to the tuner used?
 

Jncrawford18

Jncrawford18
Jun 22, 2019
31
0
0
NC
Someone told me to check the pump on the fuel filter head this morning before I start it this morning to see if the pump is tight or if I can pump it I was able to pump it one and a half times before it got tight and so far no surging also was told to watch my fuel pressure at first start up it fluctuated between 5.6 to 5.9 ksi once it started to warm up it started dropping now it fluctuates between 4.2 and 4.4ksi
 

Jncrawford18

Jncrawford18
Jun 22, 2019
31
0
0
NC
Mine has it also it's in the 100's here according to the heat index right now so I wouldn't think it would be that but stranger things have happened

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