Loping at idle

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Aug 13, 2017 | 11:05 AM

#16

z31freakify

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Joined: Dec 2012

Posts: 11,278

Likes: 1,658

From: Las Cruces New Mexico

The only time I've seen this problem as well was with one of the work trucks, it turned out the armature clearance on one of the injectors was way out of spec not even a .001 filler gauge would fit, shimmed it and the lope went away and all was well.

Aug 13, 2017 | 11:12 AM

#17

Colorado350

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Joined: Nov 2015

Posts: 4,807

Likes: 125

From: Colorado Springs

Quote:

Originally Posted by Kamstutz

I checked the fuel pressure and it was 55 lbs. It doesn't seem to be a fuel problem. Since I can start the truck one moment (waiting for the wait to start light to cycle) it runs fine and the next moment I start the truck (not waiting for the wait to start light to cycle) it romps really bad. I can switch the sequence at any time with the same results.

Okay, just for reference, I also have the fuel crossover and a new pump my pressure is at 71. I've seen it dip to 67-68 when towing here in CO. Good luck figuring this out!

Aug 13, 2017 | 11:25 AM

#18

andym

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Joined: Mar 2002

Posts: 19,402

Likes: 38

From: Bonita Springs FL

I have the original pump and an FRx and I get about 62 at idle. I've seen it dip as low as 57 under heavy throttle going up a long steep hill in OD.

Aug 17, 2017 | 12:30 AM

#19

retiredsparky

Elder User

Joined: Sep 2011

Posts: 979

Likes: 4

From: Vancouver

Agree with getting a scanner. Auto enginuity or torque pro. In my opinion, everyone who has one of these trucks and likes to do their own work should be able to scan for codes and read the essential available information from the engine. It makes it so much easier to both do your own troubleshooting and also ask for help on this forum. Guessing gets really expensive.
Larry