slight hesitation

[Stylin]

I was racing my friends Mustang 5.0L today and my car at around 5000rpms hesitated for a split second then kept pulling hard after. Any ideas what that can be? Then I tried and nailed redline again in the same 3rd gear and nothing happened.

Thanks!

[jsp98m3]

Some cars just have trouble with commitment.

[jsp98m3]

Actually, I think there are something like 8 distinct fuel map overlays and sometimes when you nail it, you are at a switchover point and the car is too rich/lean or busy calculating variables. The second time you were probably not at the same point in the computer's range of variables.

[Stylin]

thanks Jim.. so nothing to worry about then.:)

[Stylin]

So what does a ping feel/sound like? I didnt hear anything when the car hesitated today. It happened once before and both times I used Sonoco 94 octane gas.. could that be it?

[jsp98m3]

Pinging sounds like a couple of BB's being shaken in a coke can.

[Stylin]

definetly wasnt a ping then. I didnt hear a thing.

[LUIS]

The car is hesitating above 5000 rpm because it is running lean? I had the same problem on my 98 M3. I took it to the dyno and above 5000 rpm it would hesitate. I was running dangerously lean. I have a stageII RMS w/aftercooler. I while back I got bigger 36# injectors and new software from RMS and the car runs up to redline smooth. No hesitation at all. Took to the dyno and I @ 345 rwh. So it is definitly running good with good air/fuel ratio. I am not saying you need bigger injectors but re-mapped ECU to get the most out of those injectors. If those injectors are max out you need bigger ones with new software. How much boost you are running?

[paul e]

I took it to the dyno and above 5000 rpm it would hesitate. I was running dangerously lean

What was 'dangerously lean' for you? I found that moving from 93 to 94 octane made a difference for me...With 93, I would once in a while, get a very slight hesitation under hard acceleration, peddle to the floor...But with 94, this has never happened.

>>. It happened once before and both times I used Sonoco 94 octane gas.. could that be it<<

As indicated, it was just the opposite with me...94 alleviated any occasional hesitation I would experience.

[Stylin]

Im only running 6psi and this only happened twice under WOT. Out of the other hundreds of redlines Ive hit since the SC went in.. And it happened so fast I couldnt even move my eye to the guages.

[babbo]

Knock control could have something to do with it.... Knock control would do that I'd think.