91 RX-7 na wont rev past 7k...
 

Hey everyone I am new to the forum (do a lot of research here) but not to cars in general...anyways I have been trying to get everything to run right by replacing plugs+wires, setting tps etc. I have read the forums over and over again but cant find anything about the rpm hitting a wall/studdering AT 7,000-7,200 rpm. It almost sounds like it is hitting a rev limiter of some sort and slightly vibrates and hums. All I want to know is if my attention should be directed to possibly cleaning the injectors (secondary right?), changing out the fuel pump, ignition coils, etc. If you need anymore information on how it is exactly running I will help as much as I can. Also, I was told the engine was rebuilt and has around 90k miles on it but I have come to realize that whoever had it before me didn't put everything back the right way so I am going through it to make sure it is done right! Thanks

If you are hitting 7.2 K on a shift you are doing well..enjoy the car.

Great, I do know that the power drops off after about 7k and it is good that it is getting there in the first place but I am still confused and need some guidance on where to focus on checking things, thanks for the response!

I guess my bigger issues are what I deal with on idle and when driving...one thing that has always gone on is when the car is fully warm and I reach a light with the car in neutral and the brakes on it goes at or below 500 rpm and then pics back up. I tested the battery and it was bad so I changed that out and then tested the alternator and at 2000 rpm it puts out 76 amps but whenever there is a sudden electrical load it will bog and then pick up. I checked the idle screw and ever since I messed with the tps ( checked volts/resistance) I have noticed that the idle air screw does not seem to have an effect on the idle to raise it...only to lower it. Could the culprit of all this be a vacuum leak or alternator after all? Any advice would be appreciated, thanks

The BAC helps to keep the idle from dropping below 750 rpm when under the load but there is usually a slight lag at times before it kicks in. It is not uncommon if you pull up to a stop rather quickly, apply brakes, the idle dips a bit before recovering. If the idle continually bounces while standing still then that is not normal.

Sorry for the late reply. But okay, it does bounce 1-1400 rpm while warming up and then it starts to go away. Maybe the thermowax I think? Anyways, one thing that still has me a little frustrated is even when my car is warmed up if I try to keep the rpm at 3,000k on IDLE, it is not smooth. It sounds like it is slightly cutting out..like studdering not a lot but enough to be noticeable. I think this effects the smoothness and responsiveness when going WOT too. Again, not sure if that is an ignition or fuel issue. Thanks

Figured out the electrical load drop/braking idle drop. I checked the voltage drop on the battery to chassis and the engine to the chassis and both had a good amount of resistance through the line so I ran 10 gauge wire from the engine to the chassis and also another one from the battery to the chassis and dropped the resistance level (less voltage drop) and it helped! Just an FYI