91 AFM catapult.....MS options?
 

https://www.miataturbo.net/engine-pe...7/#post1045708

Looks like my AFM is to blame here. The flapper door seems to be stuck open, caused the car to run extremely rich at idle and die. Looking for options. I would love to remove that stupid thing on my turbo setup. Been running the Emanage Blue, vortech setup for about 8 years on the Greddy turbo. No real big issues except the occasion hose blow off....until today.

Would love some input on what direction to take. MSPNP2? DIYPNP? MSPNP1? Replace AFM? I've haven't been looking at the forums in years, so I feel somewhat lost on what the best/easiest solution would be for a more stable, reliable, and efficient setup. Cost is somewhat of a factor as I still have to feed and cloth the kids.

First off, I believe it's kaput, not caput.

Secondly, for a simple '91, you can't go wrong with any MS1. Either a home built one or the original MSPNP. They'll go for $200-$500 depending on how well they're working and what accessories come with them.

Of course, the smart decision would be to buy the newest generation (MSPNP Gen2, DIY MS2, 3, etc) that you can afford. With the supposedly best tune on both, the 2s and 3s will run much smoother and OEM like than the MS1, although I feel like there's nothing wrong with them. My car is far from OEM however.

+1. I would recommend some variant of PNP or something with a harness to OEM-style connectors so you can keep the OEM wiring as intact as possible. Original MSPNPs are showing up in the for sale sections on a regular basis. I've had extremely good service from mine, it's been many years since I've had my AFM installed.

Only food for thought is you want to make sure whatever piece of electronics you are buying is working. Buying new gives you a warranty. If buying used, you would want some way to make sure it's OK (unless you're handy with a soldering iron). Others may have thoughts on that.

you can go wrong with the following option: MS1.

Fix your existing AFM and find other uses for the saved money. I have been running a similar group of bandaids for 70K and the only real problems were the AFM early on and a clogged cat that would have happened anyway.

How do I fix the vein when it stays open? If I push it with my fingers it freely moves, but doesn't stay closed.

Your spring is broken. Cut the glue on top and peel off the black plastic cover, see if you can fix it. If not, it's junk anyways.

If the spring is broken, I can send you one. It is probably just loose on the shaft.