This last weekend i had my truck dyno'd at strictly performance in huston and now my truck wont go over 100mph. The guy that did the dyno tweeked the tune i had from jlp to get my a/f right and also messed with other stuff to. I noticed that he raised all of my shift pressures and changed my shift points. He made the 1-2 shift at 5700 the 2-3 at 5600 and the 3-4 at 6000. he also turned some sensors off with the predator like the EGR.
My truck will go over 100mph if i go easy on the gas but at WOT the around 4000 rpms the truck acts like its hitting a rev limit.
I am not sure what i should do about it so any help would be great.

 

 

those are awful high shift RPM's for the 5.4L

Obviously something isn't right with the tune

 

I turned the shift points back to 5400 but it still acts up at 100mph

 

ttt

 

anyone have any ideas about this? i was with svtpete at strictly performance and the guy seemed to know a lot about mustangs but not so much about L's. He was telling us how a getting an eaton ported is like "pissing in the wind". and the fact that he had the shift pts up to high. and he also implied quite a few times that we had no idea what we were talking about just because we get information from the internet. (on here)

 

well i drove my truck today and it will go past 100 if i turn the o/d off. Then once past 100 around 5000 rpm i turn the o/d back on and it keeps on accelerating.
With the o/d on all the time it wont go past 100 still at wot.

 

set all parameters back to where they were from JL, and never let that guy touch your truck again. I think it's safe to say that JL has a little more experience with Lightnings. If you're not happy with the tune... call up Jonny, and tell him what you'd like to see. I'm sure he'll work with you to get your truck where you want.

 

I agree..........

PEacE......................
Jim

 

^ yup.

 

yeah, but the thing is, pete only went there because #1, he wanted to get his truck dyno'd just to see the numbers, #2, he wanted to check the a/f and make sure they were safe b/c he was gettin detonation towards the end of the 1/4 mile. and i think that was the 2nd tune he got from JL.

 

I have set all of the parameters back to stock.
I have not tested it to se if that fixed the problem.
I have written down the fuel settings that were modified. So my question is should i leave it how johnny sent the tune to me or should i return the fuel settings back to how strictly perf set it?

 

I would give JL the info you wrote down that needed changed, and call him up to see if he would tweak your tune for you. You have all of the information from the dyno, so I would give him that and tell him your tune needs work.

 

I'll elaborate. Set all parameters back to how JL built your tune. I believe there is an option under modify tune to reset all parameters. This will reinstall the last custom tune downloaded without any of the changes you or any one else had made since the last time you downloaded the file from your computer.

Next, call JL. tell him that you are detonating at the end of 3rd gear, and send along a copy of your dyno sheet. (the first pull, before anybody messed with his tune). This will give him additional information to help tune the truck properly. I'm sure he will be happy the modify the tune. Any additional information you give him (such as the a/f readings from the dyno session) will only be able to help him dial in your tune. All of our trucks run differently. If he doesn't have your truck in front of him on the dyno, he can only give you a tune based on what works with most lightnings. With more information, he will be able to give you a tune that works for you, and your truck.

Finally, (I'll repeat), never let that guy at the dyno touch your predator again

In the mean time, just stay out of the boost if you are detonating!

edit: Grimace beat me to it!