I have 2 1988's and a 1989 rx7 the one '88 is a parts car and the other is a project that is red. I'm hav'in a tuff time with the red one it runs bad ,dosen't idle, runs rich when it first starts, if I can start it. has no power like I drive in 3rd fulthrottle and its at 3500rpm @60mph and won't go faster. I tried cleaning the injetors, changing the ECU,MAFS, and new plug's/wire's. It has great spark. I'm thinkin I'm just going to have to take the motor of the red one and put the other '88 one in. but still want to know whats wrong with it befor it's out of the car its. pissing me off any help would be better than no help........ all three are non-turbo, should have said that earlier

 

Can low compression/blown seals cause a motor to run rich? Not idling can be a result of a blown motor, too, but I think it could also be a result of a bad TPS, throttle position sensor, and that might also control your secondary injectors (I'm fairly new to this stuff so check with other more experienced people). Do the secondaries even open up until around 3500 RPM?

 

For the 3500 RPM, have you checked your grounds? is it 3500 in every gear?

 

Have you checked the cats on your car. It has 2 of them that are useless. Probably not the problem but a clogged cat will cause hesitation!

 

the front plugs always foul out befor the back plugs do. it has great spark and hits 7000rpm in nutrual the cats are old but the main cat is a "test pipe"and it doesent like starting

 

it bogs down and won't go past 3500 while driving in 3rd and almost dies when in 4th but in 2nd it slowly goes to 6500 then I shift still need help