dragger

Hello everyone...First let me introduce myself. I 've always have a passion for cars, whether it's domestic or imports. I'm from the honda-tech forum, although I've haven't been there for a while. I enjoy working on cars, so recently I decided to start my new project...

93 rx-7
Engine Modes:

Greddy Power Extreme Exhaust
Greddy Profec B
Greddy Turbo Timer
Greddy 3 Piece Intercooler
Greddy Blow-Off Valve
Rx-7 Down Pipe
Rx-7 Mid Pipe
K&N Drop In

I consider myself a tuner/street mechanic, thus all work was done by me.

However I ran into a little problem...When I floor my pedal, my rpm begins to climb until it hits 5000 rpm where it will all of a sudden shut down, engine and turbo. At this point you can see the rev needle drop not wanting to climb anymore, even if I keep my foot planted.

I'm still in the learning process of this rotory motor and would truly appreciate any help...please reply, since I spent so much time on tuning this car, I would really want to drive it to its full potential.

diabolical1

iTrader: (3)

well, i'm not a Gen III owner or guru, and i don't claim to be, but off the top of my head, i'd check the vacuum hoses that control the secondary turbo. it sounds like it may not be coming online.
however, regardless of whether or not that turns out to be the problem, you'd probably be better off either asking the Gen III forum (i've only visited once, so i don't know how they are) or psoting both here and the Gen III forum.

oh yeah ... and welcome! it's always great to see a new brother of the rotary family come on board.

1

dragger

diabolical1,

Thank you for the warm welcome and reply.

I'll be sure to double check the vacum hoses and post in the 3rd Generation Specifics (thats what you meant when you stated Gen III forum, right?)

diabolical1

iTrader: (3)

yeah ... 3rd Gen Specific ... that's it. like i said, i don't know what the atmosphere is like in there, but i'm pretty sure more of the people that would be better able to help you, check there more often than in this forum.

FD4S

dragger - I'm assuming that when you say the engine and turbo "shuts down", you actually mean that you're experiencing fuel cut (sorta like a jerky feeling, or like a hesitation).

I'm not sure what boost level you've got dialled in, and I would say it would be higher than stock judging from your mods. The 3rd gen has a range of boost levels at different RPMs where it will start cutting fuel if those boost levels are reached.

I had the same problem and sorta solved it by installing larger fuel pump and then turning down the fuel at my Apexi S-AFC, hence tricking the ECU into thinking that that the injectors are spraying less fuel than reality.

There are other ways to solve this problem and I'm sure you've already got a few ideas.

Hope this sets you in the right direction.

2-Rotor

I agree totally. Your running a wide open exhaust with just basically stock fuel and ignition maps and you are hitting fuel cut. At 5,000 RPM is right at the transition from primary to secondary turbo so in your case your hitting a boost spike which is triggering fuel cut. I would also suggest upgrading computers and a higher volume fuel pump. Hope this helps.

dragger

FD4S and 2-Rotor,

When I gas it all the way, my boost gauge hits exactly 10 psi with what seems like a .5 psi spike to 5000 rpm before I would feel the hesitation. Oddly enough, it will continue to climb ever so slowly (like a struggle) and hesitating at various levels of rpm increments while holding at 10-10.5 psi. It doesn't bounce like hitting the rev limiter in a honda, but continues to climb. After about two or three freezes, I let of the pedal...scary stuff, I tell you...

The reason I mentioned 5000 rpm was because this was the introductory phase of the hesitation.

I tried lowering my boost to 9 psi, but it still occurs, with again a .5 psi variable.

My initial assumption was either a loose vacuum hose or the fuel system (ecu, fuel pump,...). Since the whole rotory and turbo concept is new to me, I just needed confirmation.

Question???

Would the Greddy E-Manage sovle this. I perfer not to re-map my ecu (stand alone unit?) for various reasons, unless this is the best route to go.

Secondly, after the installation of the fuel controller or re-mapped ecu, would it still be necessary to upgrade my fuel pump.

So far I spent quite a large amount of $$$ (including my SSR Competions, springs, B&M ss, etc.) and the real serious moddings have not yet begun!!!

Both of your opinions are appreiciated...and I' ll keep everyone posted on the progress...

FD4S

dragger - sorry about the slow reply ... still new to this forum stuff and not sure if there's an "auto" check function thingey to update me of new changes to threads.

When you hit the fuel cut, the RPMs continue to rise, but with the funny hesitation which I think you're experiencing. Your engine doesn't just slow down and pick up again like with a speed cut.

Try lowering your boost further but not below 8psi.

dragger

diabolical!, FD4S, and 2-Rotor,


I thank you guys for all your advise and insights!

I wasn't able to work on the car until yesterday. What I discovered was a 2 inch split on one of the silicon couplers between the Greddy elbow and intercooler. Took it out on a test drive running first a 8psi and then a 10psi setting. It runs all the way to redline without any hesitations. It amazes me that that was the source of my trouble!

There is still so much for me to learn and other problems I' m experiencing with this car, thus I will be posting in the 3rd generation forum, and hopefully they'll be as helpful as you guys were...

Question?...FD4S,

Why shouldn't I boost below 8 psi? Is this bad?