Need Help

[Trivers]

I just bought a 1993 MX-3 GS, with 1.8 V6, 97,000 miles for $300. It started off not being able to run at all, the intake boot was torn. I taped it up to see and it ran great for two weeks. I just replace it with a new one from the dealer. Ran great but now around 4000 RPM it will cut out then kick back in.

I just need to figure out. I am thinking it might be the VAF sensor. I is too abrupt to be the fuel pump. No codes are coming up. Any ideas?

Thanks

[Mad Cow]

Check the VAF and see if the cone moves, mine was stuck and did something similar.

[Trivers]

The cone moves freely. Is there a way to test the VAF?

[stereoking15]

check basics of routine maintainence, check plugs, wire condition, cap, rotor all the usual becaue if it was vaf related it would run poorly all the time not just at 4k, check those simple things. might even need to do an hei conversion coil/module starting to go bad, syptoms are cutting out around 3500-4500 rpm and not going much further, backfiring, sluggish, stuttering, hard/no start.

[SuperK]

my vaf was stuck and it bucked like you wouldn't believe down the highway...

but, it moved freely, it didn't sound broken, and there was completely no way to tell if it was malfunctioning...
I got a replacement and it worked fine. they're cheap, like 30 bucks.