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LPDTuning
March 1st, 2008, 01:12 PM
Hey guys. Im new here and just got EFI a few weeks ago. Im having some issues with a truck I'm tuning. While at an idle in gear, I have a lope. I didnt change any fuel pressure at idle or any pulse width. (So I thought) I did some logging to find that at idle im demanding 4900psi but was fluctuating from 52-4700psi. So, I went into my pulse width chart and started lowering the values from the 5 mm3's all the way up to 0 over to 40MPa. And I still had a lopey idle. So, I looked at the scan tool, and moved the line around on the graph and noticed that it was highlighting the 190MPa column in the the injection pulse chart. Why is that? Is the CP3 getting weak and the valve is opening all the way to keep pressure? So, I lowered those values and it still lopes. But, load up the stock tune and all is good.:nixweiss: :help2: I have a tune in my truck that has way more fuel in the same areas, and it idles smoothly. Im learning a lot but there is so much more to go. Thanks in advance for any help.

duramaximizer
March 4th, 2008, 05:43 AM
Sounds to me like you changed a low end pulse width. That is what caused my lopey idle.

LPDTuning
March 7th, 2008, 01:02 PM
Thats exactly what I did. I knew I did, but in my logging I had a units conflict and it was logging the wrong area in the pulse width table and I was changing the wrong end of the table. Needless to say I got it fixed. Thanks!

duramaximizer
March 10th, 2008, 04:54 AM
Glad I could help.

Jared Duramax
March 23rd, 2008, 03:44 AM
i have the same issue with one of my tunes but i only get a lopy idle when its cold out. so i got a lift pump for the truck and that made me have a lopy idle all the time.

The Neens
March 23rd, 2008, 03:50 AM
i have the same issue with one of my tunes but i only get a lopy idle when its cold out. so i got a lift pump for the truck and that made me have a lopy idle all the time.

Which lift pump did you install?...Too much pressure to the CP3 and it will start to surge...I had this problem using a Holley Black pump on a LB7...

Jared Duramax
March 23rd, 2008, 04:02 AM
i put that PPE pump on that you helped me with the wiring on. i turned the pressure down all the way it helped but it didnt eliminate it.

Jared

The Neens
March 23rd, 2008, 05:35 AM
Sorry, apparently I've got short-term memory issues:D

Have you called PPE yet?

Jared Duramax
March 23rd, 2008, 11:34 AM
Yup and i went through it with Dan but im just guessing its in my tuning and i need to adjust my idling tables.

Jared