This one problem I can't fix. It has been doing this for like 2 weeks now. It just doesn't want to breath right anymore. Exhaust has gotten real loud too. Car runs very cold. Exhaust has no damage. Already checked but Will do a better check through whole system. Kinda feels like a potato was shoved in exhaust. At 4000rpms the car studders. In neutral I can rev it up all the way to 8000rpms without problems over and over and sounds very nice but when the car is in motion in every gear when I hit 4000rpms It hessitates to go past 4000rpms. Only gear it doesn't have that much trouble is in 2nd. In all other gears it does. Usually in 4th gear the car is jumping real bad a 4000rpms. It just doesnt want to go past 4000rpms. and if you make it to 5000rpms it feels like your using a VCR hitting rewind, fastforward, rewind fastforward rewind. That is how it jerks.
Any help please ??


- CoRDiTe

 

ive HEARD thats from a bad ground for your ecu. check rx7club.com, i think all you do is re ground it & the problem is solved. no biggy

 

Ground in the ecu from inside the car or outside the car to the motor, tranny or what ?

 

I have this hesitation whenever I accelerate right around 3500-4000 RPM
The dreaded 3800 RPM hesitation is cause 90% of the time by poor ground connections between the engine, the battery, and the car. Clean or replace all the under hood ground connections. On 86 model year cars , replacing/regrounding the pressure sensor's ground wire has helped (do not re-ground a 87 or later model year). If there is still a problem after that, look at cleaning the fuel injectors and (on a N/A) that your 5th/6th ports are operating correctly.

hope that helps? try searching on rx7club.com or something similar, i've never dealt w/ the problem, only heard of it.

 

I have an 88 GTU and I did a swap with an 86 GXL motor. Should I still try to reground everything ???. This problem happend after I Switched the Black main fuse in the Engine Bay. I hooked it up the way its suppost to be.

 

does your car have any cats on it? if so, rotaries tend to destroy the inside of them and then they come apart and clog up inside. i used to drive an NA 86 and it hesitated at that rpm and had no top-end and i thought it was supposed to be that slow. then i happened to be underneath fixing a crack in my exhaust and noticed my cat was plugged. a long chissel and hammer cleaned out the inside of the cat. the car honestly had 40hp more with open cats. then i bought a t2 haha.

 

A clogged cat will make for a very slow car.

 

I removed all three and put one brand new one about one year ago. It's brand new. I redid the whole exhaust from the motor back. except I kept the Mufflers and the Y part that makes it dual.. Its a Lorenzo Exchaust system. Forgot how to spell it.

 

Could anything else be the problem. I have a new fuel pump, new fuel filter, only thing old are the injectors. In neutral I can rev it up fine pass 4000. Just in gear I have my problem when Im at around 4000

 

have you had to add water to it?