Daniel60

Frustrated after all this drama of the pinging I went and tried Brent's 91 octane less tip tune and it appears to be running good with no ping. Right now I'm so paranoid I don't know when I'm hearing engine or ping. But the ping is gone. I'm running 93 octane gas. Why doesn't it ping. I don't thing this tune supplies as much torque but I think it's just as fast . Please someone intervene.

Daniel60

Please Mustang Gurus' anyone?

Wally39

Justastockmustang, I had it on for almost 2 months and it ran great. Then one day out of the blue it started knocking. JDM just e-mailed me and they told me to try and reload the tune so the computers memory can start over. They said it remembers all the fuel and timing curves etc. I will give that a try. So even though I tightened my clamps up after the MAF sensors, it still wants to use the same curves as it did before.

cekim

I'm confused - not sure what the question is?

Hopefully that does it - previous PCMs seemed to let go of the long term trim with just the battery reset - I am a little surprised they hold on to that but certainly the hardware they use is capable of storing things in the NVRAM - seems like a bad idea though...

Good luck...

P.S. I am a little suspicious though - as the long term trim should leave you very rich - not lean... (it would have tried to dump fuel in to compensate for the unmetered air - once you correct that, it would go rich)

Daniel60

The question was how come my car pings with the 93 octane tune and not the 91 tune? I think the 93 has a little bit more torque but the speed is about the same.

cekim

The difference between those 2 tunes is likely to be almost, if not entirely the amount of timing... the 93 tune has more advance than the 91...

So, for any number of reasons your setup coupled with the gas that you have in the tank cannot tolerate the amount of advance in the 93 tune...

Going to the "91" tune from the "93" retards the timing a enough to prevent detonation...

The "any number of reasons" includes:
temperature/atmosphere/altitude
engine cooling - running hot?
exhaust mods? (LT headers in particular)
bad/marginal gas in your area and/or chosen gas station(s)
mixture of gas in your tank? Is it all 93? has it been that way for at least 2 fillups?
vacuum leak (as seen in this thread)
if none of the above- then sensor malfunction - O2/MAF in theory could be giving you readings that are close but not perfect...

Wally39

Reinstalling the tune didn't help. I guess I'll have to see if my dealership can find the problem. I e-mailed JDM telling them it didn't work.

Wally39

Took it to the dealership and told them about the knock. Once they found out it had a performance tune in it they wouldn't hook up they're diagnostic equipment. He said he didn't want to chance having his 4,000 equipment burnt up. LOL whatever
I said if I return it to stock would he look at it. He said yes, but I don't think I can drive it with the stock tune in it. What's the difference between JDM's tune and stock? I'm so fed up right now, because I need someone to fix this for me and I don't know where to go in my area. If I can't find anyone to look at it, then I quess it will have to sit and rot in my garage.

cekim

If you can't find anything by looking at it - Its time to log some data - what tuner do you have? You can see most of what they can see via the datalog function of a tuner (and I would run if a tech told me he was worried about blowing up his computer - that is just silly).

Daniel60

That's a crock of s hit.