New rail pressure/timing adjust update available! 2010 added

[mikel]

I have a new update available for the U7186.
http://www.diablosport.com/ascripts/fdo ... name=mikel

This new update, in addition to adding support for 2010 applications, has 2 new adjustable parameters for Fuel Rail Pressure adjustment and Injector Timing adjustment.

Timing can be added or removed in .5* increments, while pressure can be raised or lowered in 100 kpa increments.



Enjoy!

[Trotorx2]

What benefits will this provide, I know nothing about tuning a diesel, so how will I know if these adjustments will help?

Also what other changes were made to this update? I cant fine tune my tire height with the ver. 08 that I have now.

[hromadka_jay]

I have the U7186 rev 9r11 installed in a 2007 lbz duramax.
I was wondering what is a good setting to use on the fuel rail pressure at WOT and Injector timing. I have no clue what to set it on and what benefits I should get from these two settings.

[mikel]

To be honest, if your not sure, leave them alone.

We have optimized the settings in the tunes already, these adjustments are for end users that are looking for a way to stack pressure or timing boxes, and need a more advanced tuning option.

[hromadka_jay]

I am having trouble with my u7186 when set on 120hp at wide open throttle I get a check engine light and my truck goes into limp mode. I get the code P0087 which is fuel rail pressure low. What is causing this? When I have it on 85hp it runs great almost better than the 120 hp and shifts smoother with no check engine light. Help?

[mikel]

Sounds like the fuel pump is not keeping up with the commanded fuel pressure in the 120 tune.
Most likely cause would be a clogged fuel filter.

[hromadka_jay]

Do I need a lift pump or a FPRV shim kit to get the full effect of the 120hp tune? I have 2 friends that have the same truck and the same predator. They both have the same issues on the 120 tune. We all have to let off of the throttle to allow the truck to shift to the next gear or the P0087 will come up and go into limp mode.

[mikel]

Are all of these trucks running the same revision?

It is just odd since we have not changed these tunes in 3 or 4 years and I have never seen this issue before.

[hromadka_jay]

Yes, all of our trucks have the same revision, the latest one. So what is the fix? Lift pump?

[mikel]

I want to investigate a bit....this has never been an issue in the past with these tunes.

[hromadka_jay]

Well please let me know what you find out. Thanks!

[bigdawg04]

Thought I would try the 120 hp setting on my 2007 LBZ, well had same results as listed above , put back to 85hp and all is fine

[mikel]

Ugggh, I gotta see what changed.

Can you guys write the tune, export last tune written, and then post it up?

Thanks

[hromadka_jay]

I have solved the problem! I ordered a fuel pressure relief valve shim kit and installed it today and the truck drives awesome. No problems shifting and no more check engine light. I is just bad to the bone! I guess the relief valve was dumping fuel back to the tank too soon creating a problem. Shimming the valve increased the fuel pressure and made the truck perform like it should on the 120 hp setting.

[mikel]

Wow, that is interesting.

What all was in that kit?
I think the kits we have with the EPPs are just 3 #4 SAE washers...