Unexplained lope at idle. Fuel Pressure Reg?

[hepperj27]

I have a very bad lope at an idle and the pulse width is set at stock levels in the idle cells? Maybe the problem is mechanical? Pressure regulator maybe? It just seemed to happen out of nowhere. Here is a log and the tune I was running. It gets really bad in the last part of the log when its idling.

1382613827

[THEFERMANATOR]

Does this truck have a EGR blocker plate installed? I always leave it enabled, but set the parameters so that they will never be met. Others have had issues with completely disabling simliar to what your having.

[LB72004]

can you command max psi and get it? will the pressure regulator respond to DVT pressure commands?

[THEFERMANATOR]

Also can you post a log of it at idle while it is loping with no throttle changes and it stopped? In your log I noticed you were driving and constantly changing throttle input which made it a little difficult to keep track of desired VS actual fuel pressure as desired was changing everytime you hit the throttle.

[hepperj27]

Also can you post a log of it at idle while it is loping with no throttle changes and it stopped? In your log I noticed you were driving and constantly changing throttle input which made it a little difficult to keep track of desired VS actual fuel pressure as desired was changing everytime you hit the throttle.

EGR deleted and exhaust stock otherwise sorry about no signature. Look from the 700th frame on to the end its stopped loping with no throttle.

[THEFERMANATOR]

Try setting teh lower portion of your pedal position to desired torque back to stock and see if it still does it. Also does it do it in neutral or only in drive? If you watch the log compared to your tune file, you can see it jumping around considerably for rail pressure and pulsewidth. Desired and actual are pretty close to each other, so it doesn't look like a fuel pressure regulator issue to me.

[hepperj27]

Try setting teh lower portion of your pedal position to desired torque back to stock and see if it still does it. Also does it do it in neutral or only in drive? If you watch the log compared to your tune file, you can see it jumping around considerably for rail pressure and pulsewidth. Desired and actual are pretty close to each other, so it doesn't look like a fuel pressure regulator issue to me.

It does it in neutral seems to quit in gear. Also it does it across all of my tunes. Thanks for the input

[THEFERMANATOR]

Try setting it so that your throttle based torque and torque tables are stock in the idle areas as well, or better yet try a stock tune to see if it is the tune or not.

[hepperj27]

Try setting it so that your throttle based torque and torque tables are stock in the idle areas as well, or better yet try a stock tune to see if it is the tune or not.

Yeah I thought I should try flashing in a stock tune also. Didn't work though same problem but when I was making the log I noticed that my rail pressure gauge was fluctuating about 1k psi and it was reading 3k below what the log said so I decided to unplug the gauge and try that and boom runs fine. My EGT gauge has been acting funny since I installed them so I assumed I may have some grounding issues. Have you ever heard of that happening at all? Again thanks for the input and fast responses.

Joe.