My 88 NA not to long ago has started misfiring between shifts around 4000rpm or higher, it also revs up normal to 3k drops down to 750 but when i put it in gear it idles at 1500. i was told that it was the timing belt and needed to be adjusted. want to get some other opinions on this and if anyone knows how to manually do it or if there is a walkthrough page or something i can read on how to adjust it myself rather then taking to a shop that will charge me an arm and a leg. thnx.

 

Try searching the forum for 3800 hesitation. Probably about 3800 threads on it.

BTW the short end of it, as I understand it, is that ports 5 and 6 open at 3800, and if that's not happening, it bogs. Lots of people say it's most likely bad grounds. Also, there are different issues depending on whether it bogs after 3800 and continues to bog, or just hesitates at 3800 and then keeps going.

But search for the real good info.

 

Lol at timing belt. Who told you that? Rotaries don't have timing belts, valves or cams. The intake ports are always open. "timing" comes from the port location and size. The 3 combustion chambers moves with the spinning rotor, so when one passes by the intake port you get intake, when one passes by the exhaust port you get exhaust. Simple. The exhaust port in the animation below is in the bottom left on the side, unlike the intake port which is facing you. There'd be another intake port right above the one shown if this rotary had 5th and 6th ports (there's 1 per rotor, 2 rotors in the engine).


The 5th and 6th ports are NOT causing the hesitation either. Those are the extra intake ports that open around 4000rpm for more power. They can't hurt anything or cause lag if they get stuck; you just don't get the extra power (kinda like going from VTEC to no VTEC).

It's the secondary fuel injectors that are supposed to kick in at 3800rpm. If the ECU lags before activating the secondary fuel injectors you get hesitation. www.aaroncake.net has a guide to redo your grounds, including the ECU grounds.

 

Timing belt... that's too funny!!! Go back to the guy and find out how much the part is... it would be too funny to stand there watching a dumb-*** mechanic talk to a parts supplier trying to find a timing belt for an RX7!!!

Here is the direct link posted above, http://www.aaroncake.net/RX-7/grounding.htm. If you search 3800RPM hesitation anything written about that is what your expirencing. I'd take care of the grounds first off and see if that taes care of it.

 

It's not hesitating, but misfiring.
Search for "3800 rpm hesitation", and you should find TONS of info. The above link to Aaroncake.net is defintely worthwhile, too.

 

..Go back to the guy..and ask him to Point out the timing belt..then when he shows you the Water pump belt..Slam the hood on his head!..Trust,me.this will not Hurt him,as he doesn't Have a Friggin Brain in his Head..(no Brain=no Pain!)..Actually you are Better OFF HERE..and Listen to US,Banter about it,than taking your Car to a Shop and Watch some guy GO at your car and NOT even Know where the part is OR what the **** he is doing..afterall,they have that big Sign on the wall that says that they can Charge 50-75 Bucks and Hour,because they went to school to Be that Stupid!.Suggestion,Start reading How the engine operates..then Laugh along with us!