i just bought my first rx-7, i really dont know much about them. when i bought the car, it ran great. the turbo spooled up really good too. then out of nowhere, it started to run like crap. it takes off really slow and it only has power at about 6k rpms to redline. the turbo still spools up as it would normally do. the car backfires a lot. i checked for vacuum leaks and everything looks good. the car has a walbro 255 lph fuel pump, 720cc injectors and it is street ported. it also has a 3" downpipe and exhaust. can it be an exhaust leak or dirty injectors that are making my car run like crap? my air fuel ratio gauge goes all over the place. it cant stay steady. i need help, it's running really bad. by the way, the engine had just gotten rebuilt before i bought it.

 

*starts chanting* take it back! take it back! go back to him/her/them and ask 'em to fix it. was any contract written up?

backfires would occure a lot if it's sort of like a straightpipe exhaust, mine does that and im running 1-pre cat with a 3.5' pipe.

 

^ i love it. it was just rebuilt.

i wonder by who? probably the guy who sold it to you, lol

sorry not to make fun

do yourself a favor......do a COMPRESSION CHECK