chc5e

Hello, all
I'm new to this forum and would appreciate any advice on the subject problem or direction to previous threads.
Background:
For about the last 4 years, engine would hesitate upon after gear shift and pressing gas pedal. Problem has (I believe) progressed such that depressing clutch will sometimes cause car to stall and is very difficult to restart. Problems appear very similar to that described in SSP39 ECU replacement program as well as TSB #03/92.

Several years ago when SSP39 was sent to me, I took car to local Mazda dealer and they inspected ECU and told me that correct ECU was already installed. Meaning that original dealer where I purchased car must have replaced original factory ECU. I purchased car in '94 with 5k miles on it (dealer demo).

With stalling becoming more prevalent, I took car back to dealer last week where they continue to claim ECU is correct one. Right now, they are pretty lost as to what the problem could be.

The only non-factory modications I've made to this car are a Centerforce clutch and Peter Farrell Supercars muffler in 1997. Not sure if problems are related to muffler change??

Anyway, I'd greatly appreciate any advice on a path forward.

All the best,
Hunter

Snook

iTrader: (12)

Hey,
I'm not really qualified to answer this question because I haven't had my car for long but nobody has responded for a while and I know that there is a hesitation
they call it the 3000 rpm hesitation but it actually happens at 2,850 or so and is worse when the a/c is running or you are slowly accelerating.
that may be what you are talking about...almost all rx7s have this and the most proven way to get rid of this is by getting the power fc engine manegment system.

As for problems when depressing the clutch or after releasing it that sounds like a bearing in the clutch that needs to be changed out.

about stalling out that could be a lot of problems like the intake not being secure and not getting enough air, running lean, clutch problem....it could almost be anything you will have to describe the problem a little more...Im not sure that the ecu has anything to do with it but it could since I didnt know they had a recal on the ecu

good luck-hopefully some more experienced people help you out with some replies also

Snook

chc5e

Thanks for the input, Snook.
This hesitation is significantly different than the infamous "3,000 rpm hesitation" that you point out and that I'm very familiar with.
This hesitation occurs immediately after gear shift/clutch release upon pressing gas pedal. For 1-2 seconds, car losses power as if no fuel or no air or no spark. Flooring gas during this time span has no effect. And then suddenly engine comes to life again.

reza

Try not to close your throthle all the way.
I found that RX-7 does not like when the throthle is closed all the way during shift.
Lift it up a little bit to drop the rpm, thats it. not taking your foot off the gas.

Reza

redrotorR1

When's the last time you changed the plugs and wires? And the fuel filter? It sounds like an ignition/timing problem. The MAP sensor probably ought to be replaced (cheap) and you should check the idle screw and make sure it's not torqued all the way down. If you're going to change the plugs, I'd clean the throttle body while you're in there. Sometimes, the butterfly valves can get stuck (as they get older).

chc5e

Thanks, Reza and RedRotor.
I thought fuel filter could be the culprit too but no dice. Changed it and no impact. Plugs were changed about 4 years ago and don't have much mileage on them.
What's this "MAP" sensor?
You may have something with the butterfly recommendation. What makes them get stuck? Some sort of fouling or wear or what?
Keep the ideas coming!!!