Help with accelleration

Easiest thing first: has the fuel filter been replaced? After that the throttle position sensor seems like a good thing to check. Mine went wonky on my '91 and caused some drivability problems although they weren't as bad as what you describe.

The OP should check the gas cap vent, if air can't enter the system it'll start starving for fuel after a few miles....

Just take the cap off and drive, he'll get a check engine light but ignore it.

If you don't find fuel issues, I'm thinking that it's plug wires. OP mentions good plugs but no mention of replacing wires. Miata plug wires are notorious for their short life. OEM's at 95k (and 12 yrs) ought to be pretty much shot.

Let us know, Chris

99BBB

All the above are good, but I'd had a similar issue and it turned out that the battery cable was frayed in the trunk. It actually wasn't frayed at the battery, it was frayed where the cable was bolted to the interior of the trunk, presumably to take off tension? Didn't work too well, but a new battery cable is no more expensive a repair than any of the above, and its really easy to tell. Give it a quick look- over.

-r0ll

Tks for the responses! 1st off I'll try the gas cap. It is stored outside and within a heavily wooded area. The wires were replaced about 35K ago. The battery cables check out looking good. Guess if none of the above fix,on to the TPS. Once again, tks for all of the suggestions. Bill in Va.

Well, the OP stated I was a yutz regarding automotive repair. Where the heck is the fuel filter? Nothing under the hood looks like a suspect! Bill McDonald

oem parts can be had for good prices from

the fuel filter is supposed to be replaced every 30k, but they typically last way longer. it is a large filter so it is more forgiving than many other cars. i did mine at 105k, shortly after i got the car and suspect it had never been done before. this filter is not particularly hard to reply but it is awkward and messy to do on your back. oem filters, including fuel, air, and oil, are much higher quality than the stuff sold at autozone and the like and the prices at finishline are actually cheaper than those inferior products.

If you are referring to Fram filters, you are likely correct. However, past studies showed that Mazda USA had "OEM" filters sourced in the USA that were NOT as high a quality as the made in Japan filters.