I got a tune from Mustang Tuning using the SCT Xcal2 tuner. When I first hit the gas I am hearing a marble like sound coming from the car....I believe this is detonation from my tune.....I check my tail pipes and they are black as hell......What should I do??? Should I reinstall my stock tune???? I need some help....The car is running rich as hell........... MT needs to send me a new tune to fix this problem....

 

What octane are you running? You should be running 93 if the tune is made for that and nothing less.

 

I run nothing but 93 octane in my car.....I have no idea why it is doing this...I put the stock tune back on my car and it didn't do it.....The only problem is that I cant adjust the stock tune for my 4:10 gears and my speedo is off......

 

Reinstalled the stock tune and the car feels like it pulls more and has more power then with the tune!!!!!! I need to talk to someone at MT about this problem........

 

I think you fudged something up in the motor. Your car sounds like it has marbles in it, last time I heard of this problem and the tune wasnt the problem they did a compression test found out that 2 of the cylenders had low compression, took the heads off and had to rebuild the motor. Granted this was on my friends car and had a s/c on it but i'd say you have a lil problem

 

It does not do it with the stock tune....If there was a problem with the engine then it would do it all the time, There is no detonation with the stock tune...The car pulls more with the stock tune then it does with the performance tune....So I think you are wrong....

 

You said it did it with the stock tune but whatever thats beside the case. There is no reason why a tune would go bad all the sudden they dont have experation dates you know. I think your smoking crack if you think your stock tune pulls harder than a tune that firms your shifts and advances the timing but in all honesty you shouldnt feel that much of a difference. also have to consider a bad tank of gas. May be ****ty on advanced timing but better on the stock tune. Gas stations P*** me off:bash:

 

That may be the case also....The gas may be bad. But right now the stock tune does feel stronger then the performance tune!!!!! The only difference is the shift points!!!!!! That is why I think something is wrong with the tune....

 

marble sound is classic detonation sign. you got a nasty tune problem.

 

I believe that your timing is off for the 0-2000 RPM range. Just adjust the timing down a few degrees and see if it fixes it. I had to take out -4 degrees from my tune as well and now it runs like a top.

Find exactly the RPM range in which it is "marbling", and back the timing off in that range. Not a big deal. Living in Alaska, I've found that my 90 octane seems to be a bit weaker than the rest of the world's, so adjusting my tune was mandatory.

 

It may be bad gas and it may also be that it's just too freaking hot outside. That's why I hate mail order tunes, they're never as close as dyno tunes. Definately take some timing out of the tune..

 

If it was bad gas, i would think it would run like crap even with a stock tune. bad gas is just bad gas no matter what the tune is. I would call MT up and tell them the problem and see if they can redo it for you, which they should. Also it's electronic, anyhing electronic isn't 100 percent reliable and you can buy anything new and it can break the next day, so yes it can be a bad tune or maybe someone fat fingered the key if programming it with the laptop. who know's. Give them a call.