Ropski

Recently bought my first Rotary/Turbo car. 1993 FD, 105k on chassis, 30k on rebuilt motor/auto trans.
Mods are:
Apex seals ( Assuming 3mm because it says Race Apex Seals in receipts), DP, Highflow Catted MP,CB, AEM A/F gauge, Profec B Boost controller, 550cc primaries, 550cc secondaries, and another set of 550cc injectors installed on intake manifold, fuel injector controller, 4:30 gears, GReddy Stock mount IC, Aluminum race radiator. Tuned to 12 PSI on 93 octane by Tri-Point.
My concern is on cold start sometimes it will jump to 2,200-3,000rpm, stay for a few seconds and drop to 700-1,000rpm, sometimes 500rpm. Once warm at idle it seems OK, sounds healthy and the A/F is around 12.0. Its hard to determine peak boost because of a cheap *** Sunpro boost gauge.
Also, when running it hard, once it nears redlineand if I let off the gas it backfires quite loud and some white smoke comes out occasionally. This I have quit doing... very quickly.
I have been combing through threads and its gotten me paranoid. There are no rotary shops within even a few hundred miles, and the main shop in town has only seen one or two rotaries in their shop. I haven't had time yet due to work schedual to do a compression check, or check the plugs. You guys have any ideas? I can give more info if need be. This is my first rotary so I am very weary of Modding it, and honestly everything about it before I am certain everything is able to support more power and it is done right the first time. I am used to V8's, but no I don't plan on dropping an LS1 in her lol..

Sgtblue

iTrader: (16)

Never dealt with these issues but since no one else chimed in.....
And as I mentioned at FLASHBACKS...I'm NO tuner. But....IIRC you still have throttle-body coolant line in place. So I'm guessing your Accelerated Warm-up System (AWS) is also still there. That would cause the high rpm on cold start. Try starting it in gear with the clutch depressed (obviously) and see if it still does it.
RE: back-firing......what ECU do you have? I'd have to suspect it's the unusual injector sizing you have for at least some back-fire. I've also been told that at least some back-firing can be cured with new plugs and/or plug wires if your's are old. Might also help with that unpredicatable idle too.
Also found this thread...... https://www.rx7club.com/forum/3rd-ge...g-more-170731/

Speaking of the throttle-body coolant line...I still recommend you get a temp gauge installed ASAP. Here's that thread I mentioned on how to install the gauge sensor in that line. The list of needed parts (about $5 worth) are listed in post #36. ---> https://www.rx7club.com/3rd-generati...d-idea-392910/

Acidia609

iTrader: (2)

What your describing sounds like to me to be a normal condition with light upgrades. Rotory turbo engines naturally run rich so when redlinning and letting off the gas some gas residue sits in the bowl of the cat or Dp. Thus causing a backfire. If your that concerned you may take ur car to a local smog and test your stoichiometry A/F at 4500 should be around 13.7. As far as your boost you can hook up a volt meter on the signal side and record your peak voltage assuming you have the stock 2bar pressure sensor. The signal wire should only read. 0.14v-4.9v at 2bar boost

Ropski

I still have the stock ECU right now. I'm going to look this winter into upgrading the ECU/ Replacing most of the electronics in the car ( Boost Controller, Wideband, ect...). I did take your advice and have a new Temp gauge, Oil Temp, and boost gauge ordered and on their way. Also managed to find a brass T fitting at work we had laying around which should work fine. I did find one of the oil lines running to the Turbo is leaking. I'm going to address that this weekend, I think that may be contributing to some white smoke when it backfires?
Also apparently my A/F gauge it broken or the O2 sensor is melted, it says 14.8 constantly. It will be fine since I have another car to drive and will be replacing it anyways.

gracer7-rx7

iTrader: (16)

That is a very odd injector combination... Are you sure that is what you have? Stock secondaries are 850. I don't see how you can run the stock ECU with 550 secondaries... What controls the extra 2 additional injectors? Where are they mounted??? Got pics?

Also, I'm not aware of any Tripoint tuning of the stock ECU but it's been a long time since I have run one....

Ropski

The secondaries just be 850 then, I was told they were 550cc, but the Thunked bought it from only had it a few months and didn't know too much about it. I thought it was very odd combo as well, why they didn't just put in 1,000, or 1,200cc secondaries I do not know. I will post a pic once i get home from work.

Von Hayden

good information in this post, thanks guys

Ropski

Back in business. Here are a few quick pics I snapped:

Ropski

The Fuel Injector controller:
I'm going out on a limb here and thinking this is just completely separate from the other injectors running off the stock ECU. Traced some wires from the Controller and they run right to the injectors, not seeing any going to the ECU. I'm thinking if I enough spare cash this winter, I will remove this controller/extra injectors, buy a stock Intake manifold, bigger secondaries, SS lines, and go get a proper tune on it.

Sgtblue

iTrader: (16)

Sounds like your making progress. If your smelling fuel, be REALLY careful running it until you get it handled. That strange injector set-up says that someone has been messing with stuff. FWIW, the fuel pulsation dampers also have a record of leaking with age and heat. If that's the problem it's not a bad job, but you'll need to pull the UIM off to access it. IIRC the damper is a little expensive. It can also be deleted. Haven't tried it but you can check http://www.banzai-racing.com/ (under tech support) for info on that.
Keep us posted.

Ropski

I'm thinking its the InJectors, seeing as they are 6 years old, and only 20,000 miles on them. Ill be pulling the UIM off this week/weekend to see.

I'm not driving it whatsoever, luckily I didn't sell my Acura to fund this project, or else i'd be SOL. It is a heavy flow coming out, dripping down the side of the block right next to turbo's onto subframe. I will be taking out Injectors, and sending them to be refurbished/flow tested, once I find some time to do it. Exciting... this is my first actual engine fix on this car haha. I'l keep everyone posted on the situation. After this is done My Power FC should be ordered and then off to get a hopefully nice tune done on it.

Jeep5inch@aol.com

It could be a computer or injectors. You should take your car to a shop. If you don't know what your doing you can blow up these engines very easily

Ropski

I would but I don't even trust shops in town with my DD. Checking out the injectors this weekend, sending them off to be reconditioned/tested
Thanks for your concern though lol