Mustang Boards

Mustang Boards (/)
-   Modular 4.6L Tech (https://mustangboards.com/modular-4-6l-tech/)
-   -   RPM Surging Problem/Shift Points on my '05. (https://mustangboards.com/modular-4-6l-tech/36931-rpm-surging-problem-shift-points-my-05-a.html)

Black Sunshine 07-02-2009 08:22 PM

RPM Surging Problem/Shift Points on my '05.
 
A few times a day when I drive my '05 GT (which is an automatic), I'll notice that my RPM's slightly surge.

1) This never happens when I'm just idling at a light or anything. Only when the car is in gear and is already moving.

2) For one example that happened today, I was going about 40 miles per hour, 1800 RPM's, coasting to a stop. My foot was off both the brake and the gas. Just a few seconds before I was going to hit my brakes, I noticed and felt the RPM's rise a little and looked at my gauges. The RPM's went from 1800 to 2000 for just a second and went back down to 1800.

3) Another example: As I was driving down a road at about 50 miles per hour, my foot was on the gas pedal, but I was just crusing. I didn't push the pedal down at all and the RPM's surged.

4) When the RPM's surge like this, the car doesn't accelerate with the RPM jumps. I can just feel it through the pedal and see it on my gauge. I can't really explain it. I'll be just driving along at a crusing speed, I'll feel the RPM's raise, look at the gauges and watch it, and then it stops and goes back to normal.

5) When I crank the car in the morning, the idle starts at about 1000 and goes all the way up to about 2200 for maybe 3-4 seconds and then goes back down to 1000.

6) I uploaded a new 93 octane custom tune from Justin at VMP Tuning about a month ago and the car never did this until then.


With all that being said and with #6 taken into consideration, I'm assuming that it is in the tune. If so, how the hell do I fix this? I know it isn't supposed to do this. It's not something major and I don't notice any issues with the way the car drives, it's just puzzling to me.


Also, the shift points are waaaaayyyyy too soft for my tastes. What can I do to make them more firm? I know I can change the shift points, but can someone explain to me the proper way to do it so I don't fuck something up?

Thanks for your help guys. Like always, I appreciate it. :)

spike_africa 07-03-2009 06:51 AM

Their could be some part of the file that Justin sent you that got messed up in the transfer. I would email him about that and tell him to make the shifts firmer and he will take care of you.

08mustang_gt 07-03-2009 08:06 AM

The idling issue you can adjust on the SCT if its the XCal3/SF3. Mine idles at 720 and it's great. The warm-up RPMs sounds like a bad tune. It shouldn't go up to 2200, maybe 1500 at the most.


All times are GMT -7. The time now is 11:33 AM.


© 2024 MH Sub I, LLC dba Internet Brands