Hi,

I manual converted my FD a few years back, rebuilt motor, mapped PFC etc, then around 6 months later out of no where i started getting tip in stumble when re-applying the throttle.

The circumstance for the stumble is only when the water temperature gets upto 50-60 degs C and above. Under cold start the car drives perfectly and smoothly like my friends bog standard FD. But once the water temps come up, driving smooth is not happening. Its most noticable when changing gear gently and re-applying the throttle. You get a lean event for around half a second then it sorts itself and chimes back in.

I've since tried every setting on the apexi, using datalogit with no success. Also had the whole inlet system off, tried different TPS's, ensured they are in range too and throttle bodies, injectors cleaned, again no success.

I have read a few others had similar issues but none have posted the fix.

 

Is it an emissions regulated or a U.S. FD RX7? Did you disconnect/cut/de-pin the 3 wires for emissions when you installed the PFC?

 

Its a JDM RX7. Thats imported to the UK. So no emissions stuff.

 

When it's cold, it's on a rich mapping from what I understand. When it warms up, it depends on good Oxygen sensor readings. I had a similar issue I chased for some time, turned out to be an exhaust leak at the exhaust manifold / downpipe connection. Make sure you have no intake or exhaust leaks!

 

You can set the PFC to ignore the O2 sensor readings, but i doubt that will help. It sounds to me like there is a problem with your tune. You might want to try saving your current tune to your laptop/PC, then reset your PFC to base map, go for an easy drive and see if the problem is gone.

 

I've changed every setting on the PFC with datalogit with no success. I still think its something to do with the auto to manual swap. Next task is swap the horseshoe loom and the dash loom to a manual car.

 

When I had a similar problem it was the tip in settings that helped, that few seconds as you increase throttle before it evens out and catches up to you.