Loping Idle

T

TXAustin

Cummins Junkie
Joined
Jan 10, 2010
Messages
119
I'm starting to run out of ideas. It all started when I changed the oil (same filter and oil it's always had) and put on GDP's 2mic filtration. A few days later (unless somehow I missed it right after) it sounds exactly like this:

http://www.youtube.com/watch?v=61nGLFn_-8M

Fuel pressure is normal (20psi)
Rail is normal
All electrical connections are good
Installed TC modded rail a month ago with 25/27k PRV's. No leaks and it's all tight.
No excessive blow by, going to take the oil cap off and check again tomorrow.
Both FCA's are fairly new. Thinking of trying the old ones out to see if it makes a difference.
Injectors are about 2,000 miles old.
Runs normal after about 1,500RPM and boost builds. Seems to be no power loss.

Even though it sounds cool I know somethings not right. What else could it be?
 
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mine wasnt near as lopey, but i had the 2micron on my 06 and it had a minor light lope. id say bypass it and see what it sounds like. might have to go with a different filter setup. Id think the volume isnt enough for you dual CP3s. I mean it will work but it might not be giving you the volume needed for the 2 HPFPs to pull through a filter that usually is good for 1 plus the stockers a 7 micron i think. pressure could be fine but volume is key. Id try going around the GDP filter or finding a different filter set up or a 2nd 2 micron for the other HPFP.

I could be wrong though, i prefer dinosaur power anymore.
 
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Drasko said:
mine wasnt near as lopey, but i had the 2micron on my 06 and it had a minor light lope. id say bypass it and see what it sounds like. might have to go with a different filter setup. Id think the volume isnt enough for you dual CP3s. I mean it will work but it might not be giving you the volume needed for the 2 HPFPs to pull through a filter that usually is good for 1 plus the stockers a 7 micron i think. pressure could be fine but volume is key. Id try going around the GDP filter or finding a different filter set up or a 2nd 2 micron for the other HPFP.

I could be wrong though, i prefer dinosaur power anymore.
Click to expand...

Makes sense. I'll pick up a fitting to connect the hoses together this weekend and see if it makes a difference.. If it does I'm going to be mad I bought that 2mic kit. I would think that if it wasn't getting enough volume the top end would suffice?
The 2mic set up is between the CP3's and AD btw.
 
i ran a 2 micron and its a good thing to have dont get me wrong but you might need to add a second 2 micron in parallel to help keep the volume up.
 
Well it still is there today. I took a video off my phone (lost camera charger) so I'll see how it sounds off of there. I'll post it up in the morning.
 
Mine does this when my supply pressure is too high.. I have PPE dual fueler with a Dmax pump on top..They Do NOT like lots of supply pressure or they do this...I had to add a regulator to pull my supply pressure down to only 6-8 psi for it to stop...
It does NOT hurt the power..


Is one of your pumps a Dmax pump??
This could be it...
 
999fe9e3.mp4


Here it is. I'm going to get a better one tomorrow as it was not very pronounced in this video. Engine was warmed up and in park.
 
Big Swole said:
Mine does this when my supply pressure is too high.. I have PPE dual fueler with a Dmax pump on top..They Do NOT like lots of supply pressure or they do this...I had to add a regulator to pull my supply pressure down to only 6-8 psi for it to stop...
It does NOT hurt the power..


Is one of your pumps a Dmax pump??
This could be it...
Click to expand...

My top pump is a Dmax. It has been since first installing the duals and I've changed nothing. Since day 1 both pumps have seen 20psi of FP with no problems. To make sure that wasn't the issue I pulled the fuse of the AD and with no pressure the sound did not change at all. Like I said the only reason this lope came about was when I put on the 2 mic filter kit and changed the oil... That's it. I'm going into town tomorrow for more fuel tubing to bypass the 2mic kit and see what happens. My FP gauge is set after everything and installing the product did not change the pressure. I am going to take the FCA's out and clean them also just to make sure that's not it.
 
Ok I got a few more videos. It doesn't sound as pronounced (this is just off my iPhone) but you can hear the main idea. You can hear it the best inside the cab, so when the camera is turned away I'm just facing the mic towards the rear.

8060bd8c.mp4


a4f8e6ab.mp4


7822f326.mp4


b0d3bb89.mp4
 
my truck has a very similar lope to that also. i noticed it after i got my injectors put in, at the time i still had a single stock cp3.
very interested to see what you figure out.
 
I'm hoping to figure something out soon. It sounds really cool it's just not right. Just like having a big cam in a gasser.

Help me understand this. Long story short I need more fuel line to bypass the 2mic and I'm not sure I'll find that this week.
With PRESSURE the exact same how is their less VOLUME by adding the 2 mic? I've been trying to figure it out in my head but since the sensor is set up after the 2 mic I'd think I would see a pressure loss if it was a fueling issue. Motor itself seems to sound normal, so I'm starting to think it's nothing important. I'll look more into it tonight again.
 
at idle i wouldnt think you need that much volume, i could see it being a problem when your using a lot of fuel but i would hope the filter would flow enough to let the truck idle right lol
 
Well considering the idle started after an oil change and adding the 2mic that was the first suggestion on here. If both pumps aren't getting plenty of volume there can be air in the lines and make it sound like this. I don't believe this is the case but I need to bypass the 2 mic to make sure that isn't it. If I can't find some fuel line I'm going to clean the FCA's tonight.
 
that makes sense to try it first.
ill be watching to see what you find out.
what size fuel line do you need? if you cant get any by next weekend i have some 3/8 and 1/2 and will be in corsicana. let me know if you need some and i will bring a piece with me.
 
I have an Airdog so it's 1/2". I'll be back in Dallas tomorrow where I can get fuel line easy. Where I'm at this weekend (southern OK) parts are harder to come by and there's not many people that need 1/2" fuel.

Any other 850+hp 5.9's out there that do this as well? Maybe a cam will help?
 
dont think im at 850 yet but im not too far off. im getting a cam installed this week, ill let you know if it makes any difference
 
That would be great thanks. For comparison please take a good (over a minute length) video of the exhaust note, and then one after the cam. I know they will smooth out the idle but have never seen a before and after video - only read about it.

Bypassed the AD with no difference. Hooked the truck up to the tractor trailer, and put some seafoam in the 2mic filter and ran the crap out of it keeping the EGT's above 1000* and the RP over 20k for about 25 miles. I think now I'm just getting used to it more than anything. No excess oil, no blow by, no abnormal temps. Just bugs the crap out if me that something isn't right. Not sure what I'm going to try next...
 
Contact Us for married COV valves that should clear it right up.. if Not just return them..
 
Todd, I'll try and give you a call this coming week. I haven't even thought of the COV's.
-Austin Karnes
 
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