It looks like out of the blue over the last 3 months my AFR's have become on average 1 - 1.5 points leaner and I can feel it, especially at idle.

Maybe because its the summer, but I want to eliminate the potential that it is the FPR. The car has 30k miles on it so I doubt its the fuel pump.

While I know its not catastrophic and can be easily remedied by a table update, I am paranoid because I dont remember if I had modified my tables for this same exact issue before or not.

Are there any known cases or patterns of failing stock fuel pressure regulators on turbocharged miatas?

 

not that I know of, you could test the rail pressure tho to make sure.

 

fuel filter?

 

I popped one a while ago. It happened really quickly while I was tuning. I did a couple of pulls and noticed the AFRs were half a point leaner suddenly, and then I started a pull and it pegged at 17:1 as soon as I entered boost. I nursed it home at 15-16:1. Pinched the return line and the pump was fine, so I swapped FPRs and it solved the problem.

It happened right after I installed a DIY dual feed rail, I swapped back to a stock rail after that. No idea whether it's coincidence or a shaving I missed or what.

 

Id need a gauge for this yea?

At 30k miles?

You really think it could do that.

 

pull the vacuum line off the FPR, if there's fuel there you know it's bad.

 

Nice, I will do that ASAP.

Should I do it with the car running or with the car off?

Thanks Scott.