Cant rev past 6500?!
 

I just installed an RP(RX7.com) catback, a cone filter and new ngk plugs and wires in my 90 gtu. the rebuild was running perfect with 65k on the clock
my part throttle response is normal, but at WOT i cant get past 6500 even with the clutch in, and i do not make even close to normal power. any insight would be greatly appriciated.

Im thinking possibly the 5/6 ports arent opening, as my power drops off right at ~4000 ish rpm.

most likely they are not opening. If you wanna know for sure, just as a test, wire them open and try again.

i thought s5 5/6 ports wer opened by the air pump, im new to the 7 (only about 2 months) but i dont understand what would cause it. is there a writeup on wireing them open?

On your new exhaust, do you have a tube that comes back on your lower intake manifold?

If not, theres your problem.

Just wire them open as a test. Test first, find your problem, then wonder why you have that problem when you found it.

my new exh is only the ypipe and everything after, so the tube is un molested. i will try wireing them open though.

with the car not running, (parked), you should be able to hit the buzzer. The 5 and 6 port will not change aything. it's only to get more power when the second injector cam up. you will run rich but this should not be a problem the past the 6500 rpm.

dumarjo

i know i should be able to, i used to be able to, but now i cant, im trying to figure why. perhaps the injectors cant keep up, with the (however slight) added airflow?

ok, forgive me, i searched but i cant find a write up on wireing the 5/6 ports open, i cant even find the actuators under the hood, should i be able to put my hands on them from the top of the car, without pulling anything else. i really dont want to pull the IM unless i have to.

well, the 5/6 ports are working properly, but i still cant go above 6500. it feels like a fuel issue, since the car doesnt stop making power untill more then ~1/2 throttle. anyone think a new fuel filter, and cleaning the injectors might help? im not really sure how to go about cleaning the injectors, other than to soak the tips in injector cleaner and run some gas through to flush them out.

advice is still very much appriciated.

5th and 6th ports need back pressure. wire them open or zip tie what ever you got.

been told the'll barely open if you change exhaust out to a more free flowing and thats what happen to my roommate's rx7 so we open it and it fixed that problme.

there next to your smog pump if you still have yours. gota pull off the spring loaded actuaters and then zip tie your ports open.

its not the actuators, itll hit redline no problem stuck closed or open.

stuck closed itll feel a little down on power up top, but not anything too noticable
stuck open youll feel power gone down low but a big boost up top.

mine never worked right, stuck shut all the time. was a big difference sticking them open.

if you cant rev past 6500 then its a fuel issue. replace filter, strainer, and if nothing yet then the pump.

this is a misconception.

okay dude.. make sure your AFM is somewhat level. if its in a weird angle, it wont operate correctly due to the gay flap it has.
nex, DOUBLE check your injectors, make sure they are intact and making contact (not just being plugged in.
those two reasons have been my problems in the past with this type of issue.
the actuators somewhat look like cupcakes with a candle in the center .. =D

u have a 90 s5 rx7, the 5/6 ports dont use the back pressure in youe exhaust there for u have no tube to connect to the exhaust cuz its already oparated by your air pump. just wanted to clear that up

i'm leaning more towards your injectors not firing.
when mine was rev-limited like yours it was because of all the injectors not firing..
i changed my pass harness which fixed MY problem.. rotted wires are gay..
just look over your wiring.

ive got the fuel filter out right now, and wow...i can barely blow through it. its pouring out now, but when it stops im gonna put the new one in.

EDIT: when your injectors werent fireing. did your car idle well, and make power else where in the band?

well, new fuel filter = porblem not fixed. ive noticed the car makes normal power till 4k then completely flatlines, and barely makes it to 6500. any ideas?

the problem has worsened such that i can only get 6krpm out if it now. its really starting to irritate me now, any ideas at all would really help. because i cam stumped.

would a blocked cat cause this?

yea it could also cuase it to feel week. overal, clogged cats make it feel like your draggin around dead weight.

well, i still have no answer, im reading way rich all the way through the band on my narrow band, and the car isnt smooth, wont rev over 6k, and wont pull above 5k under load.

ive replaced, fuel filter, plugs/ wires. and checked the actuators. the car used to make a loud rattling noise from the cat area, which has gone away. but i am completely stumped. any ideas at all?

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Go to the NWS hobby shop by the Dive and pull the cats off on the lift that is there. Your first Precat might be a chunk of crap. This was a problem with my N/A a few years back when I was a student there in 2000.