03.5 MSP Bucking

[YouDontGnomeMe]

So, I've had a problem recently with my MSP. If I accelerated "spiritedly" it tends to buck pretty hard, usually right around 3500 RPM's. If I accelerated gently, it doesn't do it. I've noticed it seems to do it mainly on cooler nights, but regardless, it's preventing me from really enjoying the car, especially since I don't know why it's doing it and don't want to cause any problems. I'm running full synthetic in it, if that makes a difference. Anyone else have this problem, or have any idea what might be causing it?
I've had the check engine light come on a couple times (altho not for a while) with a code saying it was running lean, not sure if that is causing it. There's a high pitched whistling coming from somewhere along the intake line that I've been told is the sound of a vacuum leak, altho we haven't been able to find any leak...

 

[hornsfan10609]

Only run premium, replace your spark plugs with NGK ZFR6F-11 gapped to .028-.032" and if you still are unhappy with the hesitation buy and install an SSAFC.

 

[evilmonkeyMSP]

Start with new plugs, thats most likely the problem. Gapped as horns said above.

If that doesnt do it the replace the coils and wires.

 

[YouDontGnomeMe]

The plugs are less than a year old (I replaced them when I got the car), but I'll check them. What's a SSAFC?

 

[evilmonkeyMSP]

Plugs cost $8 to replace so might as well.

The plugs are less than a year old (I replaced them when I got the car), but I'll check them. What's a SSAFC?

 

[hornsfan10609]

It's a piggyback controller for the stock ECU, it intercepts and modifies the MAF and 02 signals that the ECU reads. Basically it eliminates the hesitation the stock tune has, and it is tune-able so you can change the tune for each individual car and modification. It's the cheapest and most popular tuning solution for the MSP.

 

[YouDontGnomeMe]

Where can I find one? I've googled it, and it doesn't seem to return anything useful...

 

[hornsfan10609]

There is some information here on the forums, it's a Split Second brand Air/Fuel Controller and they are made specifically for the Mazdaspeed Protege. You can find one here on the forums or buy one new from ProtegeGarage.com
http://www.mazdas247.com/forum/showthread.php?123620555-AFC-SplitSecond-PSC1-Map-Library

 

[Spiced MSP]

get the ssafc, you will be glad you did

 

[Nc MSP]

get the ssafc, you will be glad you did

I 2nd this.... By far the best thing if done to my car so far