I always run the same fuel, same tune. Whats a few cents going to really mean anyway? It's not even a cup of starbucks for one day.

 

I agree with what's been said here. I sometimes even get the wrench light immediately after changing tunes when I fill up. I figured out that I need to get the tank as empty as possible, fill up, and then drive the car or rev the engine until I know that all of the old gas has been detonated. That seemed to take care of the problem. I've tried the 87 and 89 tunes lately to save some cash, but I'm back to the 92. The car is just too much fun with the 92 tune!

 

If the OP is running, say, an 89 octane tune with 89 fuel and then fills up with 93 octane and swaps to the 93 tune right then and there, yes, he'll ping until the 89 fuel that was left in the pump, fuel lines, filter, etc is flushed through and replaced with the 93 octane. Of COURSE it may ping under that scenario.

 

Thanks everybody, I'm sure that's what it is. Not letting the 93 gas get to the engine. I guess I'm changing my tune too early. I'll make sure I run the 93 octane a few miles when switching from 87 before I change the tune.

 

So what did you do, push your car home from the gas station after putting in the 93 gas??? No you started it up and drove it home which cleared out the 87 or 89 fuel that was in the filter and line... I have used my 87, 89, 91, and 93 brenspeed tunes and have never had the engine ping after startup... I have even changed tunes at the gas station on a long trip from Augusta, GA to Benson, AZ. Pulled into a gas station just into Alabama and said Wow they sure are proud of their gas and whipped out the tuner, dropped form 93 to 89 tune, filled up and kept on truckin... When I got back fro Arizona, I filled back up with 93 gas and drove home and tuned it back to my 93 tune. Never had a ping one out of the engine... I would check with Brenspeed.....

 

I agree. It doesnt sound right to me. Never had a ping in any motor...well...except this crappy POS 89 Taurus but that was cuz the only gas in town to be had probably was 80% water from the town creek.

 

C'mon, guys. Pay attention.

The OP was running a tune calling for higher octane while a lower octane tune was still in between the tank and the injectors. Some of you are talking about switching to a lower octane tune OR running the lower octane fuel out of the system before switching to the higher octane tune.

Apples vs. oranges...

 

Hmmm I had something like this happen yesterday.

Running empty, i filled up on 91 shell for my 89 Brenspeed tune.

Later in the day i reloaded the 89 tune from my xcal as I sometimes do, a ritual i picked up from the threads saying a reload every so often will restore some oomph back to the performance.

But the bullitt began to immediatly ping severely as i got on it. I don't see how it could it could happen? Even if bad gas it was 91 on an 89 tune? Sorry to hijack.

Nick

 

Socal6r, I got horrible pinging immediately after switching tunes from normal/near granny acceleration. Not from flooring it. So far, the best advice for me is to pick a tune and stick with it. I need to stop switching tunes so much and fill up with matching or higher octane than my tune is set for. I guess this is one of the dangers of running aftermarket tunes. I would never ever have this problem if I had left the car stock tuned. That being said, I still like my 91 octane Brenspeed tune best. It runs the smoothest, has the quickest acceleration and gets the best gas mileage. And that's what I was looking for.