Hi

I'm having some trouble getting the car in a drivable state so i can get it to a tuner for mapping. Seems to be running on one rotor under 2.5k rpm and just dies without some throttle input .

Previously stock JDM S5 turbo engine with no running issues and good compression, here's the new engine spec:

• TO4E
• Turbo-back exhaust
• AP Engineering PowerFC (no AFM)
• 1000cc primary / 1600cc secondary
• Sard RJ type FPR (Set to 2.5bar)
• FMIC
• Twin power/new leads/new plugs
• bosch 044
• denso 3 bar MAP

Its getting through fuel like there's no tomorrow, so much im considering building an oil refinery and getting a dedicated oil pipeline from Russia! the front rotor plugs are soaking with fuel when i take them out after running the engine for a few minutes.

Here's what I've tried so far:

• Set fuel pressure to 2.5bar
• Set injector sizes in power fc with hand commander
• played around with the PIM voltage, no effect
• de-flooded the engine many times, cleaned the plugs, tried brand new plugs

What should I check next?

My only concern is im still using the stock IAT, and every conversion kit for a 3rd gen PowerFC (eg the Banzai racing one) comes with a replacement. I've been told it shouldn't make a difference and I have the AP engineering version ?

Before I resort to getting my tuner to come to the car and put a base map on it, is there anything else I could check?

TIA

 

Prime the pump. Don't try to start the car. Check your fuel pressure regulator and see if it's holding pressure. An after market one will slowly lose pressure, it may take 5 minutes. If it's dropping quick, I would suspect a leaking injector in the front rotor, hence you are soaking that one, and not the rear.

 

When you changed the primary injectors to 1000cc did you reduce the percentage the 55%?

 

Put the stock primaries back in. 1000cc primary for your setup is complete overkill and will increase the work/hassle to get it to idle right. Trust me on this--don't run more primary injector than you need.

 

Seemed to be holding pressure ok when it was set

Yes, I can't remember the exact % but i changed the value based on my tuner's advice. On a side-note, i know you do the conversion kits for the 3rd gen powerfc's, what is your opinion on keeping the stock IAT sensor? Should it make any difference? I have the other sensor, but didn't use it as its a different connector to the stock loom and I don't have a harness.

I think I'll go with your advice here and try going down this route. 1600 secondaries should provide more than enough anyway when it comes to mapping? just didn't realise the larger primaries would give me such a hard time you live and learn I guess!

Thanks everyone for all your advice

 

With the 550 primaries if you're concerned about excessive injector duty cycle you can have your tuner raise base fuel pressure to 40psi or 3 bar (43.5 psi) before tuning. If you put the stock injectors back in the car should hopefully be more driveable although I would stay out of boost. Is this tuner experienced with Rx-7's and Power FC's ?

 

+1 for this. I run 720's for primaries and have no issues going lean ever. Tuner got my AFR's down in the high 11's to low 12's at lower RPM cruise but that's the best we could do.

 

Definitely, I'd only ever take it to someone who specializes in tuning rotaries. Over in the UK he's very highly regarded - one of the best rx7 engine build & tuners in the country.

Strangely enough he didn't seem to think the larger primaries would be a problem to map with, but since i need the car to be drivable off boost 550cc is the way forward.

Thanks guys, I'll keep you posted with how i get on

 

did you have any problems remembering where the injector plugs went for rotor1/2? it sounds like you have both primary injector plugs on the front rotor...and secondaries on the back rotor.