I need some help! I have a 1985 rx7 with 12a engine and stock 4bbl carb. When i firdt purchased the car about 9 months ago it ran great but now it doesnt. When i first got it i could hit 130mph easy but now im doing good to hit 100mph! since ive got it ive had to put a new acellerator pump on the carb and a new clutch.I'm thinking the problem could be in the air feul mixture or in the timming but i don know how to do adjust either! Any comment would be greatly appreciated!

 

before you start trying to adjust the carbie and timing, how have you been keeping up with basic maintenance?



ignition components?

fuel filter?



aside from that, since you fiddled with the carbie, then i might look there first for any performance issues.

 

it was service completely by the man i bought it form about nine months ago. Im not really sure how often i should check/maintain those components. It accelerate like normal alth the way up to about 80mph then it just limps along its almost like it looses alot of power at hgh rpm/speed. It is a new engine though it was put in the car right before i purchased it.

 

I'd definitely replace the fuel filter. I had a buddy that had similar symptoms and it drove him nuts for a few weeks. A lot of people don't change that during a regular "service" and our cars are old and most have sediment in the tanks.

 

I wrote a driveability diagnosis article a while back on the Mazspeed forum. It's a good place to start.



http://www.mazspeed.com/diagnosingdr...typroblems.htm