still has ping, need advice

bshort · Post by **bshort** » Sun Mar 04, 2007 9:45 pm

U7153 on 01' f150 screw 4x4 w/ 5.4l. No spark issues and fuel delivery is fine. Still pinging at wot near shift points. Already retarded 10%, less, but still pings. I'm considering keeping the 10% and adding fuel in the 4-7K range. Maybe 1-2 values richer. Any advice? No ping with stock, but can't adjust speedo and gears.

ChrisDiabloSport · Post by **ChrisDiabloSport** » Mon Mar 05, 2007 2:33 pm

Which tune are you running? What octane fuel are you running? If you are running the Performance tune with only 87 octane fuel in the tank this could be what is causing your issue. Try pulling another 10% spark from 4 - 7k and see if this helps get rid of your pinging.

bshort · Post by **bshort** » Mon Mar 05, 2007 9:56 pm

It is the only tune in the unit, says "diablo tune." I use 91 shell fuel. I already pulled a 10% retard. Do you recommend a total of 20%? Seems a little too much...

joeyz71 · Post by **joeyz71** » Tue Mar 06, 2007 4:45 am

Hey, this sounds like what I just went through. Have someone do a back pressure test on your cats. Mine were plugging up, so they were hollowed out and now she goes like a raped ape (yes- that's the technical term). Check your knock sensors too. This may be of help or a waste of time, so good luck.

ChrisDiabloSport · Post by **ChrisDiabloSport** » Tue Mar 06, 2007 12:13 pm

The Performance Tunes in the Predator are made for 93 Octane, so pulling the 10% out would help, maybe you could try removing another 5% and see how it does? Do you have any other modifications done to your truck, like a CAI etc... If you think you might be running on the lean side you can check your Long Term Fuel trims under using the Real Time Data section under Diagnostics. As long as they are in the +/- 8% range at idle and cruise you should be fine.