summerfordw

I have a 2008 Mustang GT .that has a Roush supercharger installed at the dealership where purchased.. ran great .. i upgrade wheels and tires to 20's then took to local ford dealer and had them do routine service (oil change) and calibrate the speedometer to match new tire size.. then i was told that they have to keep my car over the weekend because there computer crashed when recalibrating my speedometer .. then went to pick it up the following tuesday and then my tpms has a hard fault.. they reset my tire pressure sensors twice while i waited but still faulting ..then left car the car for another week and when picking it up my reciept shows tech checked and found nothing wrong..then after they test drive it and put 34 miles on my car .. so my question is that my cars pcm has been recalibrated by roush performance and now after driving it it doesn't feel like it has the same power and under load it rattles really bad like its pinging..so can my car still run with the supercharger if the pcm was reset to factory calibration??.. I'm trying to get some input before i take it bad to the dealer and let it sit for another week.

LilRoush

If I were to guess, when the blower was put on, it had the Roush tune put into the computer. When they tried to change something, it locked up. If they reset it, it's a time bomb (assuming the ping you hear isn't something screwed up already).

Don't drive it. Get it back to them ASAP. Make sure they understand the car didn't have the stock tune on it. If they returned it to stock, everything will be off as far as fuel and timing.

Can I ask why the speedo needed to be adjusted? Did you not get the stock diameter when you upgraded wheels?

summerfordw

Thanks for the input lilroush, I just got off the phone with Roush this morning and they said that on my car its possible that it will still run with factory tune..and I installed 20x10 rims on the rear and 285 tires on those rims compared to the factory 17s with 255 ...made another appointment to take car back to dealer tomarrow .. guess ill tow it there..I don't believe the engine it hurt yet but they did put 34 miles on the test drive and nowing mechanics driving it im sure it was a real hard 34 miles!

svfetter

Your PCM needs to be sent back to Roush for Reprograming for the changes you made. The dealer should have know that they could not correct for the tire changes you made without sending back to Roush.

I believe after providing all the detailed info to Roush, your new tune from them will correct all your issues and get your speedo correct for your new tire size. Good Luck.

LilRoush

285 and 255 are the width... what were the full sizes of the tires?
If you do drive it, stay out of boost. The stock computer won't recognize the fuel system upgrade, so you'll have an A/F struggle.

AKRA

It might be better to call JDM and buy a tuner with a custom tune. Then you can adjust for tire height any time. With the a smaller pulley you can get a few extra poney's.

He did the tune on my 07 GT with a Saleen SC and I couldn't be more pleased. Ive been running it for a couple years now.

Good Luck,

Al

summerfordw

Thanks for the info AkRA.. i didnt want to go with aftermarket tuning due to the car still being under Ford/Roush Warranty ..that was the only reason I took it to the dealer to get the oil change and speed set...On a second note I dropped the car off Tuesday @2pm before work and then got a call back today at 10am saying that there is nothing wrong with the computer and that all the parameters have been checked with there equipment while on the phone with roush.. so the service advisor tells me that theres nothing wrong with your car .. so i say have you drivin it to listen for the problem ...oooo nooo we dont want to drive it if its detinating ..but it didnt stop them last from the 34 mile test drive at the last visit.....anyways guess ill see if anyone else at a local dealership wants to remove my computer and sent it directly to roush to get checked.. BIG A** CAN OF WORMS I OPENED UP HERE!!!!

AKRA

I had something similar happen to me once while making adjustments with my tuner. At the time it was still under warranty. Anyway when I went to adjust the tune, it blew the fuse to the MAF Sensor and the car ran bad with pre-detonation during acceleration. I took it to Saleen in Troy, MI where the supercharger was installed. They found my problem.

After reading the manual to the tuner it says to remove that fuse before tuning because this can be a common occurrence. Maybe the dealer blew the fuse while trying to change the parameters for your tire height change. Can't hurt to check

Good luck,

Al

LilRoush

So they say it's fine, but then won't drive it. Seems fishy.

Soldier GT

^^agreed...