Ev7

I will appreciate any inputs on a little trivial problem I been having with my 93 Rx-7. Its been driving me nuts ever since bought the car in 1999. I got a R-1 model with 50K miles bone stock when I got it. The seller put a new fuel filter assuming it was going to take care of the small hesitation it had. It didnt. When I first start the car in the morning it runs perfect, without any hesitation. As the engine warms up and it reaches operating temp. (double throttle opens) the hesitations starts showing up. In any gear as the RPM`s start to climb 1.. 2.. 3... (theres the usual boost drop and then recovers whith the typical twin turbo sequential hesitation) everything is fine until it gets to 3500-4000 rpms; as the rpms climb theres a slight hesitations that last for less than 1/2 second then recovers then keeps climbing then it happens again for the same period of time. It does this 3 to 5 times before reaching 7000 rpms. It feels like a bucking. If you upshift it happens again. The factory manual calls it hesitation; not to be confused with a surge. As the engine gets hotter the more noticeable and frequent this happens. I am not sure if is the computer retarding ignition due to knock or fuel cut off. The car is almost all stock with the exception of a K&N air box filter an stainless steel fiberglass-pack muffler. I run stock boost (10 psi) and i have no engine computer codes present, I checked the fuel pressure and is at around 36psi and during acceleration i climbs about 10-15 psi higher. I have installed an Autometer Boost, Air/Fuel and Water Temp. gauge, also a GReddy BOV and turbo timer. All works fine. I always use 93 premium gas and change the oil regurlarly. The dyno figures are about 15% less of what I spected but the charts (and gauge) show the car running rich during acceleration. This got me puzzle beyond believe, the dealer has no idea what could it be. I you have any advice, please reply and thank you for reading my boring story.

RETed

Uh, wrong section?


-Ted