I have an 85 1.1L Rx-7 that seems to have developed a small hiccup and studder when it idles and it begins to pop and shake when i push the throttle all the way up to 4K on the tach then it smooths and runs right. Now if this was a piston engine I would know how to diagnose it... but since i have never messes with a rotary ^^; i am going to need some help

 

well all the ones me and my brother owned are first gens. and i'm hear to tell you the way to get rid of the crackle and pop is all in the exhaust piping. We went from cat, to no cat and glass pack with a coffee can muffler to glass pack Monza dual tip. The Monza helps out a bit on his 85 13b gslse.

the 12a's we had to do some carb work along with the exhaust and timing. those are the two things to check. Also while you're at it do a compression check.

another thing....when it warms up to you have the choke in or out?

 

I use the choke right when i start up and I have it fully pulled untill it pops it self off then i just drive i also noticed a collapsed Radiator hose after my car cooled

 

Took it out a few moments ago and when i stopped at a stop sign in neutral my idle went to the first notch above 0 and popped and nearly died when i gave it some gas to get it to go.. Its gonna be sittin

 

I'd get a timing light from autozone and check the timing on it. they should be able to show you how....although i question some of the ppl that work there. If its not the timing its a vacuum leak or the carb that maybe causing the hesitation.

Also while you're there you may as well test the compression to be sure that there's no blow-by in the mix.

One more thing to be safe. Pull the spark plugs and be sure they're not fouled because it sounds like you're having more problems than just at 4k.

 

Well pulled the plugs and they were worn out pretty bad so i got a set of motorcraft from Auto zone.. Called the local mazda dealer in NC to get what gap they were supposed to be and i get told i have to use NGK's instead of the Denso's that were in there and the motor craft i had just gotten... is this true?