hey guys,

so i've got a 89 RX7, 13b non-turbo:
and once it seems to warm up and stays at a steady operating temp. it hesitates when accelerating .. between 2200 -4500/5000 RPM roughly this happens in 2nd gear to 5th, ushually the worst in 4th and fifth but seem to be bad in 2nd recently .. NOW i am told an easy fix could just be fuel filter .. i think that's to easy for this problem .. im also told it could be my ignition / spark plug wires ( which look recently replaced, but i could be wrong ) .. or my last resort which i don't wonna get into inless i have a sure opinion, would be my fuel pump..

what do you all think ? your input is much appreciated!

Thanks,

Daniel

 

I would start by checking for any error codes: https://www.rx7club.com/showthread.p...55#post5131155.

 

i do not get a check engine light at all, besides this problem the car runs GREAT? does checking for codes still apply?

thanks

 

I don't own an S5, but I believe you can still get a code without seeing the check engine light. I know sometimes it can come on only briefly. It's simple to check anyway.

The more in-depth way to track down a potential problem is testing voltages at the ECU pins per the FSM fuel and emissions section. There is a table with various values you can test for to check the various sensors.

 

might be in limp mode from the OMP not working properly. when ever u try to give it gas it will hesitate like mad. especially at high rpm. what weight oil r u running? s5 OMP's are picky

 

The common bad ground hesitation usually comes in at a more precise RPM than what you gave, but it wouldn't hurt to try. Simply take off the body and engine ground wires and take off the light corrosion with sandpaper, do this for the battery terminals too and see if it makes a difference.

 

ya the s5 i believe is 5k rpm. thats when the secondaries kick in. s4 is 3800

 

No, it's not at 5k RPM. All NAs have the secondaries trigger at 3800 RPM & 0 to -2 inHg vacuum. S5s also do not seem to suffer from the classic 3800 RPM hesitation that happens to S4s.

 

car that old i would replace fuel pump it's So! easy to do and they don't cost that much and while at it check the fuel condition , suck up a sample from the bottom of the tank , you may find out that there's gunk and rust and junk inside your gas tank .
that issue is one that people cannot figure out and end up selling RX-7 in HeLL of a good shape and just needs a new gas tank and fuel pump .
it would seem that cold start and up to nice warm up all runs fine but then starts to refuse throtle , no.. . nothing to do with warming up but the dirt in fuel getting all up off the bottom and in to the fuel pump .
check in to that and good Luck