Hi guys new here, my motor has about 3k miles now, and when I go to give it full throttle it bucks in third gear like if it's having a red line or something, but it breaks through it if I keep on it, maybe ignition problems?
My Mods are:
Arc Intake
Downpipe
High Flow
Exhaust

 

Sounds like fuel cut.. how much boost are you hitting when it cuts out like that?

 

Stock ECU?

 

Where are you located?

 

Yes sir, stock ECU I believe, no more then 10lbs is what my boost gauge reads, and I'm located in California

 

You didn't list a boost controller in your mods. Either you forgot to mention it, or you don't have one. If you don't have one, it's likely that your boost gauge isn't working right. With those mods, you could easily be hitting 15 psi.

At what rpm does your engine buck? At what rpm does it break thru the bucking? Does it do it every time?

Where in California?

 

No controller, but I do have one to install, and it bucks at about 5k and will break through it alittle but it does sound like fuel cut like if it's at redline and I will get off the gas, it's weird because it only does it at 3rd gear and up

 

Probably fuel cut. 1st and 2nd gear happen so fast that the fuel cut doesn't engage. If your boost gauge is only reading 10 psi, you need to replace it.

 

Stay off boost and get an ecu such as a power fc and a tune or at the very least a boost controler to lower the boost. You will blow that motor in no time if you keep driving it that way.

 

Thank you guys for the help, you think if I put two cats back on it will help?

 

why not tune it instead?

 

+1 ^

once you start modding the rx7, you really should get an aftermarket standalone ecu that can be tuned correctly to your specific mods...

if you can't afford to go that route right away, then yes adding back pressure to your exhaust setup is definitely a must, iirc some guys even made up simple restrictor plates to add enough back pressure to avoid boost spiking...

the stock ecu is only good for very moderate mods, meaning intake/exhaust (by exhaust i mean stock catt'd midpipe and aftermarket downpipe and catback) while maintaining stock boost levels.

 

good

if not the same thing happen to me. Since we do not read very well translated into Spanish.

To me it sometimes happens that I throttle in 3rd gear and the turbo pressure gauge gives blows, does not blow continuously, but it raises and lowers the pressure like I was crazy.

I just took reameniya catback and admission. The problem can only do in 3rd.
thought could be of any vacuum system electrovalcula etc.

then if I do not understand, can be a fuel cut??

greetings and thanks.

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buenas

no se si es lo mismo que me pasa a mi. Puesto no se lee muy bien traduciendo al español.

A mi me ocurre a veces que doy gas a fondo en 3ra marcha y el reloj de presion de turbo da como golpes, no sopla continuo, si no que sube y baja la presion como si estuviera loca.

yo solo llevo catback y admision reameniya. El problema solo lo hace en 3ra.
pensaba que podia ser de alguna electrovalcula del sistema de vacio etc.

entonces si mal no entiendo, puede ser un corte de combustible¿?

un saludo y gracias.

 

So I put my car back to stock except intake it ran Cherry after , but I was driving all of a sudden it started running on one rotor , maybe it fouled a plug , I killed the engine right away when this happened any thoughts

 

well, looking at his list of mods, he should not need a tuned PFC and this doesnt sound like fuel cut to me
I would have first looked at a sequential problem and ignition breakup
anyway, if you are running on one rotor you have a serious problem and you might want to pay someone to give it a look

 

The car needs to go to a professional. It sounds like there is a lot of stuff that just needs to get sorted out. It happens. These cars are getting old and fickle and in the hands of the wrong person doing "repairs", it only gets worse.

There are a bunch of rotary friendly shops in Cali. Find one close to you and take it in. You should be good to go in no time.

 

+1

and most def does not need to be wasting money on PFC there very limited and a waste of money to say the least.

If he or he does intenD to get a comp better to spend the money on a full stand alone comp that will take care of the whole problem, leave massive amounts of room for tunning...PFC will not cut it...

 

Yes indeed it's at a shop alright, spark plug wires were the culprit, one came off the coil pack

 

hmm, i've seen plenty of PFC's push 500-700WHP, for years without any hiccups. while not the most tuning friendly EMS they are more than capable for most applications.

but this sounds like a new dead motor and a reminder to people that boosted cars need to be professionally looked over if you want them to last. if it ran like a dream and then went to one rotor, its most likely it was leaning out, especially with the symptoms listed in the original post. if the engine sounds like it is cranking unevenly while attempting to start it then start putting money in the piggybank or sell the car ad chalk it up to lesson learned.

it's just sad to see all these cars floating around with poorly put together modifications, ticking timebombs being sold off to unsuspecting buyers.

 

Glad it was just a plug wire. Get a new boost gauge.

 

Motor is fine now, is was built by Jrx very well known here in so cal karack

 

i wasn't trying to say the engine wasn't built well but more that people modifying their own cars generally lack knowledge and then sell the cars because they know there is issues, all for you to figure out the hard way. i missed one post while skimming through the thread, but you'd be surprised how many people wind up buying one of these cars and the first time they drive it hard *boom*, no matter how well the motor was built you always have to remember that it is 50% motor and 50% everything else around the motor. being generous to how much the motor can handle when there is outlying issues.