^Lol.

Now if you got some of that blood in the fuel and the oil mix you are one gallon of coolant shy of a rotary witch brew.

 

By the way, that pipe on the bottom of the BAC comes to the pipe thing that goes to where that stock BOV (bypass air) system hooks up right?

If I'm not using the stock set up, should I cap of the bottom pipe on the BAC?

 

That needs to see some vacuum, route it somewhere into your new IC piping. On mine, I just used some flexhose and welded a nipple onto the air intake inlet and hooked it up. At least I think that is what you are talking about....

 

Holy crap dude! Sucks about the finger. The BAC isnt routed with the stock BOV. Glad you got the fuel situation figured out and you got that damn rats nest out. I'll see if I can stop by sometime and give you a final runover.

 

Alright guys... Today was exciting and frustrating all at the same time.

We finished putting everything back together, (tranny driveline, UIM, ect. after de-flooding the engine she started right up.


Now, I want you all to know thatI still have the N/A exhaust system and it isn't bolted up to the turbo system.


She did a few... Interesting things.
1. Has an idle that won't go below 1.6 thousand RPM
2. Doesn't have good throttle response. (Almost dies, then revs up.)
3. And, here's the one that has me stummped... Even when I have the engine running at 3 grand RPM's she'll do her best to die as soon as I let the clutch out. I've only been able to save her once. By pushing the4 clutch back in all the way and pulling her out of gear.

I also cannot find where the knock box plugs in and I've heard that the s4 ECU needs the box in order to run well. Where does it plug in and what color male plug does it use on the harness?

One other thing the ground / resistor looking thing that is bolted on to the clutch slave cylender broke today... What is it and what would happen if I wasn't running it? (It is currently unplugged.)

I'm still at school, so any quick reply would be awesome... I'm hoping to get her drivable by the time school is out... I MISS MY CAR!! TT_TT


Please and thank you,
Scott.

 

1. Do you have the thermowax on the TB still? If so, check that it retracts when warm.
2/3. What's the compression like? I'd also search around for vacuum leaks big enough to kill the engine at 3k.

Are you using the S4 NA harness? There won't be anywhere to plug in a knock box. It's all but useless anyway, so you can ignore it. It has no effect on how well the engine runs.

That's the condenser for the oil pressure gauge. It's there to save the gauge if the sender fails, but you can go without it.

 

For odd thing three on my list... I know that the stock ECU cuts fuel to the rear rotor when the turbo is spooling above 8 psi.
Would that cut the power just enough to kill the engine whilst under load of first gear ect.

And, how does one go about checking the thermowax system? I think that both of the wires may be severed from the harness. I'll double check that tomorrow. Hate having an old and crusty wiring harness.

Last thing for the night, the oil pressure gauge was reading through the roof. Is that because the condenser is broken? Before it broke... The gauge didn't show any oil pressure.

 

You have the oil pressure guage on teh wrong connection. Take a picture and that will help.

The thermowax is mechanical, not electrical.

I believe you should check timing, (get it close by the "stabbing the CAS" method). Then check your TPS sensor using a DMM (do a search for the exact process). Next search for vac leaks.

Do you have a boost guage? DO you have a wideband o2 sensor? If not, get them ASAP!!!!

If you do have a wideband, what is it reading?

Good Luck!

 

Alright, so today was slow progress, but progress none the less.

We started by doing a compression test. After pulling the schrader valve out of the gauge, we hooked everything up and I have 100 PSI of compression on all sides of each rotor.

Then came the crimmping of the thermal wax wires together... We noticed that they were disconnected. So, after crimping them together we noticed that in the process of fixing one problem we snapped the brown/yellow colored wire. We couldn't tell do to the aged color fading... The wire connected to the rear iron on a ball clip.

After fixing those two wires. We pushed the car outside. (It's a bit loud and the instructor doesn't like it in the shop without the ability to put an exhaust hose on the car.) She'd start right up if I held WOT and then cranked on the engine.

Idle was at 1100 or so, but wouldn't let me give it any gas at all without threatening to die. (And, after she dies she won't start back up unless I pull out the secondary plugs and vent the engine like that.) Anyways, after sitting for a while I can really REALLY slowly ease into the throttle and rev her to 3500 at that point because the exhuast isn't connected, (I'm getting one fabricated for the turbo to cat.) the turbo spools up above 8 PSI. We all know that with the stock ECU that at above 8 PSI the rear fuel injection is cut off. You can really hear a difference between one and two running rotors too....

As soon as I'm able to get the engine to rev high though, the idle drops to 2200 and won't go any lower, no matter what I do.

Final thing for the days work...
I had her held at roughly 3400 RPM's and I put her into first... The second I start to let the clutch out she dies on me.

Now, I tried adjusting the resistor on the passenger side shock tower. All the way to Rich and all the way to Lean showed no difference. When the car was idleing at 1100 and at 2200.

Here are my thoughts and I'm not honestly sure if they have any worth because I've never tried to fix a car without an exhaust. But! I'm thinking that with the exhaust off the O2 sensor might be reading way lean, causing the fuel to richen up and then kill power that way. I'm also thinking that without the back pressure of the exhaust, the turbo is overboosting causing the ECU to cut the rear rotor. I don't know what the rotary engine needs any back pressure for aside from the turbo though... Could the lack of an exhaust be the source of all my issues?

Please and thank you!
Scott.

 

I ran without an O2 sensor on my t2 for years, couldn't tell the difference.... Without any backpressure on the exhaust it is definitely boosting easier, so you are reaching fuel cut faster. Port your wastegate if you havent already, get a FCD, get a wideband 02, but that's all stuff after you get it running right. +1 for checking the timing, and although it sounds retarded, I've definitely done it, make sure you're plug wires are hooked up correctly. Also, make sure the TPS is connected, and that the BAC is getting air.

 

Hey guys! Miss me?

So, I know it's been one hell of a long time... But, I met up with the local rotary club and had a lot of my problems helped and such.

This is the update to what's going on.

1. Took the car to one of the guys in the club to have him diagnose it. Apparently the engine had low compression on one seal. Not surprised with all of the abuse I put it through trying to learn about this.

2. The engine was rebuilt and street-ported.

3. And, about the end of summer I finished breaking it in.

Since then, I've just enjoyed my horrible mileage running to and from the university. (Damn me and my led foot.)

Today is the day that I've decided to continue with the project.

Here's my list of mods:
We've got ourselves an '86 GXL with and S4 TII Swap.
The engine has been rebuilt and street-ported.
A 12-14lb. flywheel. Came on the engine from Japan so I don't know much about it.
Walboro 255L fuel pump.
Mazdatrix driveshaft to mount the TII tranny to the N/A differential.
A 2" custom fabbed downpipe welded to the stock exhaust. (It has no O2 sensor bung.) Meaning I'm running without an O2 Sensor.
A nameless brand FMIC set up.

So, here's what's going on:
The main thing that's bothering me and that I feel needs to be addressed. Is that the engine runs horribly rich. I've got my rear left speaker mount torn apart so that I can get to the harness and disconnect it.

Here's how I have to start my car;
Option 1: When the engine is entirely cooled down, I can usually get it started by just turning the key and putting light pressure on the accelerator.
Option 2: If it doesn't start right up, (happens when I put too much or too little pressure on the gas, or if the engine isn't all the way cooled.) I have to open the rear hatch and unplug the fuel pump harness, turn the key until the engine starts to run on the fuel it has, then hurry and plug in the harness before the engine dies.

As you might guess, that's a bit of a problem. Especially if you ever pop the clutch and not give it enough gas at a busy intersection. Lol, funny stories for sleepy days.

Now, today I'm going to install a fuel cut switch where I can reach it in the drivers seat. But, I also want to actually fix this problem that way my engine isn't always running so rich. (Unless I'm boosting at 7k RPM's.)

So, I was thinking of the possible problems.

1. This entirely a problem with the lack of an O2 Sensor meaning the engine is just going off of other sensors, and using the regular pulse width even though the Walboro is making the injectors leak extra fuel in.

2. The injectors are just leaking way to much fuel.

3. The fuel pressure reg. is incappable of letting fuel flow like it's supposed to making the engine run rich.

Is there something I'm missing?

I don't know. Some outside opinions would be nice as I don't have auto shop any more and can't bounce ideas off of anyone that speaks car.

Please and Thank You Guys,
Scott

 

A lack of an 02 sensor will definitely reduce mileage, but the walbro isn't helping either. Those things jack fuel pressures up much higher than stock (w/ the stock FPR), so everytime an injector opens, you get more fuel into the engine. At idle it's especially bad (about 10psi extra), so hopefully you've figured out that cranking the variable resistor all the way lean is needed. Dirty injectors are possible if you did not get them cleaned before the install, but it's not always the case.

Before going the typical fuel cut switch route, consider this alternative: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/looking-car-has-hot-start-problems-499744/. A switch placed on one of the ECU wires can give you the option to dramatically reduce injector D/Cs during hot-start cranking.

 

That is an amazing find sir, but I live in Boise ID and the temp often reaches negatives in the winter. I installed the fuel cut yesturday and it seems to be working fine for now.

And, with your info on the fuel pressure and such, I'm thinking that it's finally time to go to a programable ECU. If I'm capable of adjusting the pulse width I'd be capable of preventing this problem in the first place correct?

 

Using a switch instead of permanently cutting off the wire would allow you to enable it for cold starts, but disable for hot starts. You'll still have a switch, but it would work a little better than a fuel cut switch & not require so much extra cranking.

A standalone or Rtek stage 2 would allow you to adjust duty cycles/pulsewidth for the start map, idle, cruising, WOT, etc..., but the real fix for a walbro is an aftermarket FPR. The stock one just can't flow enough to keep fuel pressure from spiking.

 

I just cut and soldered extra length into the power wire under the dash. Then, clamped them into an on off switch. Extra little bit of anti theft or something like that I'm sure. Lol. (I will justify that five hours of work somehow. I tore up the interior in the hatch before one of the guys told me to just reach under the dash.)

And, I've been looking at some FPR's online, but I haven't found any reviews on ones that match up with the FC. Any ideas on ones?

Just so you know, my goals for future engine performance are;
1 BAR of boost with the BNR stage 3 kit.
750cc injectors or so, (probably coupled with the Rtek7 2.1)
And the Corksport Exhaust set up.

I'm looking for something that can handle that set up but be humble enough to bite the bullet of just a streetport for now.

Thanks RR88