Hi I was driving my car around today and the car has a really hard hesitation about when it hits 5k rpm's, dont know if I should call it a hesitation, because it will completely fall on its face. Other than that everything is working good. Mods are aluminum radiator, front mount intercooler, hks cast stock looking down pipe, apexi dual tip exhaust and a stock main cat. Car also has a new fuel pump and sock as well as a new filter. All the vacuum lines were re done as well.
Richard

 

sounds like it could be ignition related. how old are the plugs, wires and coils?

 

I am not really sure, but I am going to get some plugs and wires and go from there,

 

Are you under 1/4 tank?

 

Full tank

 

Curious as well as I have similar issue. How is your idle, is it oscillating? I think I have a vacuum leak and it's causing the momentary rich (bog) mixture. Unfortunately I dont have a wideband installed to diagnose. Only seems to happen at full throttle, doesnt seem to occur during partial throttle.

 

You don't mention some important pieces of information: Was it doing this previously, what ECU are you running, when was it tuned. If it's ignition breakup it would be worst around peak torque, which sounds plausible based on your description... but give us more information.

If it's in fact ignition/coil related, the IGN-1A coil kits do typically cure a lot of the RPM hesitations with the vastly increased spark intensity. Complete Package - IGN-1A Ignition Upgrade Kit + LHD Mount (FD3S RX-7) - SakeBomb Garage LLC I'm not saying to start throwing parts at the problem without knowing the cause... but if it's indeed ignition breakup check out that link

 

Hi SBGarage, the hesitation seems to be most of the time but not always. Also the car has stock ecu.

 

Have you checked/changed plugs? Wires? I mean you can start digging in and replacing plugs, wires, checking grounds. If you move to a new coil setup you get new direct block grounds, direct fused battery power to coils, direct battery ground, and a much much stronger spark than stock. We've found most of the hesitation (associated with ignition issues) are cured with the IGN-1A kit. Complete Package - IGN-1A Ignition Upgrade Kit + LHD Mount (FD3S RX-7) - SakeBomb Garage LLC


Obviously it's not a silver bullet... if it's a map sensor issue, fuel issue, some sort of vacuum leak or wastegate issue... it could be a million things, but assuming it's ignition related the kits have cured many rev range hesitation/hiccups as a side effect on many customers stock setups with other performance benefits . **Just a note though, I'm not trying to sell you on something you may not need, and obviously can't diagnose this remotely**

 

Um try changing the cat . My cats in my v8 choked it pretty bad and I was struggling to hit 100km/h (new zealand) 60mph (american)

 

Turns out previous owner put larger injectors in my primary. Incredibly rich mixture when crossover occured.

Hope you find your fix.