When I first start my rx7 (1987 na) Its fine, and at low room its fine. If I were to give it up to 4000 it missfire or seems to skip. After it warms up its runs fine. I can floor it all day. I dont know were to start. Is there some question you guy could ask to help me narrow it down?

 

Any time I hear of issues at 4k rpm, first thing I think of is secondary injectors.
Not sure why it would clear after warming up though.

 

Is there a fuel cut based on temp?

 

It does not feel/sound like a missfire. It seems like a fuel cut.

 

Is the car modified or stock?

 

When was last time you checked timing?

 

As stock as I can see. I have never checked timing.

 

You might want to check the water thermosensor if a hot start engine runs fine from the get go in addition to a cold start engine running fine after the engine has warmed up.

 

I well just replace the thermostat and as for the timeing...no idea how check that

 

Are you confusing the thermosensor with the thermostat? And using the advanced search feature will provide you with 100's of threads related to timing.

 

I be check timming this weekend. Thermo switch, yes I was getting it mixed up sorry. I am looking for were is is located right now.