For the last week I have been experiencing a strange cold idle fluxuation. This started after I removed the Smarty, and the X2 is turned of (has been for a long time). I have also recently changed the Exhaust brake pump, and had the #4 injector line break (this occured the same day I first noticed the surge).
My exhaust brake is usually always on. I'll start the truck, and it will idle normal - fuel pressure runs around 8000 psi. Then I put it in gear and first thing I see is that the fuel pressure starts spiking up to about 10000, then down to mid 7000, then the exhaust brake starts kicking off when the pressure goes high. If I turn the exhaust brake off, the pressure settles down. I took a video of it with my phone yesterday, but it saved to my phone memory (instead of the card), and I cant get it off of that. I'll take a vid with my camera this morning and post it.

I've got an appointment with the dealer on Monday - they want it overnight to check it out, but I'd like to see if we can figure this out. I'm also going to pull the Quadzilla box off since I never use it, but that will also get rid of my fuel pressure guage (I think.....).

 

So here is the video of what I'm seeing:

 

I really don't see what has you concerned? The slight changes match your grid heaters as seen on the volt guage. Looks pretty normal to me for a cold start. What exactly are you expecting? My truck changes more than that on any given day but there's nothing wrong with it, its a north american diesel truck, not a Honda.

 

No, its the opposite of what the grid heaters do. They put a load on the motor, as opposed to spiking the fuel pressure. And the spike is shutting off the exhaust brake (as if I had given it some throttle).

I expect it to work like it has for the last 60 thousand miles.

 

I can't pick out what you mean from the video but maybe someone else can. I see normal loading of a cold engine and the computer compensating for it.

I don't think expecting an engine, of any kind, to remain exactly the same over it's life is realistic. Small variations are going to occur as it ages. Sorry I can't be of much help.

 

I guess the audio is probably not real goo on the vid.

Here's the sequence:
Start (exhaust brake off)
Fuel pressure reads around 8K
Put in gear - fuel pressure fluxuates slightly
Engage Exhaust brake - fuel pressure begins to spike up to 10K, when it does the exhaust brake shuts off. If I leave the E-brake on, the pressure will drop and climb, drop and climb, with the E-brake turning off and on with the pressure changes.

Fuel pressure does change normally, but only by about 500psi. This change, greater than 1K, is not normal, and is causing abnormal cycling of the e-brake.

Also, notice the the rpms are staying constant, so its not a change in RPM (as I recall seeing when the heater grid cycles).

 

In the words of my big Bro, Just bad mojo!!!

Maybe it has something to do with the three inches of rubber sitting on the highway NW of Sidney earlier in April!

Hope you get it figured out.

Your little bro.

 

Hey old man!!! Having fun farming in the mud? Thinking about planting rice???

Service Dept said they couldn't find anything, or see anything on the computer. Took it home and put the Smarty back on, and the issue went away. On one hand, it was good - I reprogrammed the settings on the Smarty - apparently I had it set to the lowest Torque Management, and the lowest fuel pressure. So that's why it seemed a little low on power.

My hunch is that its the X2 and their infamous wiring harness. I'm going to pull it and see if the symptom is still there.

 

Glad your little baby is feeling better.

I never thought I would say this but this moisture is starting to get to me. I have been shut down since last thursday and its not looking like I am going to get back into the field for at least a week. Forecast is 70% chance of snow and rain tonight through Friday and then chance of rain all through next week. We got at least 1.5 inches of moisture in the form of rain and snow since last week. Sure would have been nice to have most of the crop in before this.

Later.

 

That would have been the first thing I tried JThiessen. All the issues I ever had with a Quad box would happen upon startup. Simply turning it off doesn't help either. It has to be totally removed or at least it did in my case.....

 

I've always been fairly happy with the way the trucks have run on Quad products - but every item I have ever had from them has had to be returned a minimum of one time, most of them twice. The rail pressure on them also concerns me a bit.

 

Ditto for me. I really like the power curve with Quads stuff.