Car runs fine till the second turbo comes on but starts to kinda stumble about 5k rpm and then surges and doesn't want to wind up. I just installed a HKS DownPipe. Rekon my gas isn't up to par? It's only 90 octane as thats all the station had I pulle dinto and I needed gas.

Maybe adding 5 gallons of aviation fuel would help or is it something else?

It ran fine before the DP install.

 

Fuel cut?? Whats your boost level when this occurrs??

 

How fresh are your spark plugs? I'd suspect ignition.

Dale

 

about 11-12 psi of boost

I thought the 3rd gen didn't have a fuel cut?

I'm a 2nd gen guy but just bought a 3rd gen also.

 

If you're still using the stock ECU, fuel-cut may be your problem, or savior actually.

What other engine mods does your car have?

 

oh, i just checked it on the way home and it's boosting to about 14-15 and thats when it starts to stumble.

Only other mods I know of are a HKS catback and a K&N. It had a Greddy E-manage on it before I bought it but it was setup for sea level. I'm 3300 above. I have the E-Manage, just haven't put it yet or messed with it.

 

Wait, so you are running the stock ECU and 90 octane fuel with 14-15psi?

 

damn 14-15 pounds, hopefully you have an a-m ecu. Shame on you if you don't. Fd's aren't like the FC's where I heard the stock ecu is capable of more. You must have that new anti-det-device everyones talking about.

 

I usually run 93 exclusively but i needed gas and they only had 90. I just installed the DP today. It was only boosting 10-11 before I put it on.

Should I take it back off and put the stock precat back on till I get a piggyback?

 

http://www.scuderiaciriani.com/rx7/fuel_cut_info.html

 

Oh and does anyone know anything about the Greddy E-Manage?

 

Your best bet right now is a boost controller. You are just experiencing boost spikes which the controller will take care of without a problem.

 

I would reccomend you try to make a home depot boost controller for the time being, and see if that will be able to control your boost. I wouldn't boost again until you have some decent fuel/boost control in that car.

 

Had the exact same problem. Turned out to be a leak in the pressure side if the tca and also a sticky turbo control solenoid. I recommend pressure testing the tca and upgrading the stock solenoid to a mac valve or similar. I dont believe the stock solenoid was ever up to the task of managing pressure. I also upgraded the cca solenoid and the turbo control 2 solenoid just to increase reliability of the system.