Wargasm

#1 - Stay FAR AWAY from the Mazda dealer. They will ruin your car and overcharge you.
#2 - It's obvious you know very little about this car. That's OK, we all started somewhere. Right now it sounds like you need professional help.
#3 - Go to KD Rotary
#4 - Who's this Bart Grande guy? I've never heard of him... if he has -anything- to do with the state your car is in now, don't go back to him because he clearly has no clue.
#5 - Oh yeah don't run a single turbo without proper fuel injectors, pump, timing, custom-tuned ECU, etc, etc!

AImec Racing

You can run the single turbo with the stock ECU, just be sure that all the selenoids are still plugged, if not the car will rev on vac but will run like crap under load. If this is not your problem, chk selenoid failures by doing a diagnostic test and chk the engine codes...there is a black tiny box on the driver side under the hood that reads "diagnostic" . Run a cable from TEN to GND (the leyend is under the box cap) and chk the engine codes at the cluster, (long flashes means 10, 20, 30 etc...short flashes means 1, 2, 3 etc...) example: If you see 2 long flashes followed by 3 short flashes that means engine code = 23 (i think that one is the fuel temp sensor). you have to turn off all engine codes in order to run the car...

AND DO NOT OVER BOOST, KEEP IT UNDER 12 PSI and you'll be fine...

AImec Racing

...and your secondary turbo not spooling problem was probably the charge control actuator loose signal hose,,, so you would have owned me $150!!!

You would like to research and READ before attempting going single or do any mods...all this stuff could help:

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

djseven

iTrader: (56)

Limp mode seems to be what it is doing. Does it buck like crazy under acceleration and backfires? Once again why even build a single car and leave in the stock ecu.

RuSkY RaCeR

ok, i checked all the wiring.

the engine runs on both rotors. i disconnected one, then the other. it ran on both.
there is definite spark on all the wired and plugs. I had about an inch and a half spark between the plug and the wire( the wire fell down and started sparking near the plug).

the only reason i dont have an upgraded ecu now is because i just spent sooo much money on the turbos alone. im working this summer to get haltech or something better that people use on these cars.

i was only going to run the car on weekends anyway with the stock one. Shouldnt it still run on the stock ecu ? (im only trying to get 8psi out of the car right now) shouldnt the stock one handle it right now, or is that why im having problems?

ALMEC RACING: what do you mean by "just be sure that all the selenoids are still plugged, if not the car will rev on vac but will run like crap under load." because that is what is happening it revs fast in neutral, but when under load it runs like crap.

im still thinking its the timing that is messed up. is there anyone here that can explain to me how to set timing?? or point me to a direction to where i can get some instructions??
that would be great.


is there anyone else close to state college (Penn State)? maybe you can come down and take a look at what is wrong.

thanx

RuSkY RaCeR

no backfires or buckles... it runs smooth through all the rpm.

the reason for the single is to get rid of the rats nest and to go to a simpler setup(alot less things to fail theres no levers , actuators, or anything closing and opening on a single) . ( right now i dont need extra power or anything like that) i just want a car that runs.

the horsepower was a flat line from 3k to 7k... no bumps no gains or losser (liner line)


o and on the stock turbos ( almost a year ago now ) all the charge control actuators were plugged in and were fine ( or at least that is what the dealership told me)

bart grande was on Monster Garage. he was on the build with the herse. he has a shop in cali, and build one here in PA (dyno shop). He is the only one around with a dyno here within and hour drive.

is there a manual somewhere on the net from which i can find the timing section?

thanx

rx7what

iTrader: (6)

I just watched that episode of monster garage like 5 minutes ago. Also what he ment by all the stuff being pluged in was the the electronics on the rats nest have to be left and pluged in. or the ecu gets pissed. I ran a stock ecu and single for a little while but i stayed at like 5psi. just to be safe. I would not go with 8psi. the stock ecu doesnt even run off a o2 sensor(only at idle) it has preset maps for stock turbos. so unless your single flows exactly the same CFM at the exact PSI as the stocks I would run way less boost. Also there should be no way your timing is jacked. its electronicly controlled

RuSkY RaCeR

so what your saying is i have to get some kind of engine managment, and all my problems would go away?

if thats the case, im buying haltech the first paycheck i get.

thanx

mattmaclennan

The stock ECU goes into "limp home mode" when it gets faulty or "0" readings from one of the many sensors/solenoids. A favorite in the UK is the OMP. For one reason or the other it packs up and sends the ECU to "default/limp home mode". Many things can cause it. But you are right, why shouldn't you be able to scrap the twins and get a single and run the car on the standard ECU? You can, the only major difficulty is that the volumetric efficiency of the intake and exhaust systems have hopefully improved a great deal. The ECU is programed with the VE of the systems as a given value. When you start changing the VE, the ECU won't compensate for it, as it has no real way of metering it. The same effect is found when porting the engine. Unlike when you turn the boost up a PSI or 2, the ECU will measure that and adjust the fuel and timing acordingly. The NET effect is that you will undoubtedly run the engine lean at the same boost you were running on the twins. The best way to overcome this issue is with a programable ECU/EMS and having the car mapped with a wideband lambda sensor on a rolling road. Then having the car tuned for cruise on the highway etc. A short term solution might be to get an adjustable rising rate fuel pressure regulator and set it to run higher fuel pressure when under boost (1:1.7). So for every 1 PSI of boost, you get 1.7 PSI increase in fuel pressure. I don't know at what point your fuel pump will give up, but it might be really drivable, you never know?

Hope that explained a few things, sorry it's not in "American" my spelling is crap in English english, let alone American english!

RuSkY RaCeR

can www.kdrotary.com trouble shoot my car and give me a definite reason why my car isnt working right? it is about two and a half hours away from me, but if they can figure out what the problem is, its definetly worth the trip.

i dont want to keep buying new things things that are fine, i just want to fix the problem i have right now and have the car running half decently for now.

if my car isnt going to run, whats the point in upgrading things?

im beginning to wonder why i bought a car that no one knows how to work on.

pp13bnos

iTrader: (1)

I'd buy a power fc for an ecu. Its a proven ecu (like the haltech, but much easier to install.) CJ

kenn_chan

They are going to tell you to get an ECU thats programmable, you are in limp mode after reading the other posts, and your replies #(&$(#$&#(stock ECU ) I can see the problems it would cause. try driving it at 3~4 PSI until you get it to a place that can put an ECU on it and tune it or else you will be buying a new wngine.

kenn

GoodfellaFD3S

iTrader: (213)

Yes. Take it to dave, they *specialize* in FD RX-7s.

APEXL8T

I didnt see what muffler you are running.......but this happen to me. My first rebuild had an New Apexi Dragon cat back.(1st RXguy) Car would not run good.Had larger secondaries from RC. Then sent to Don Marvel of Marvelspeed took car......said secondaries may be dumping too much because it would just run slow even at full throttle. Nice guy...stumped him(2nd RXguy).I then drove it to Austin...to MZM. Mohamed figures it out and installs everything extra I had and said look at this when I got back there to pick the car up a week later..(flew home unplanned of course after flying into Dallas)The brand new Apexi muffler had a plate still in the flow path that wasnt cut out!
It had enough flow to let the car run but just didnt seem right. Fast Freddy cut it apart and took it out! He now has it. Maybe examine your exhaust flow......far fetched but things have happend.
Just something that happened to me...and any of those shops can co-oberate.

AImec Racing

OK...first of all.... your chk engine light is ON?.... if yes... you need to chk which engine codes are stored in the ECU (the way i already told you). There are two kinds of engine codes: the non-reversible ones and the reversible ones. The non-reversible engine codes will cause your car to go limp mode as is called here... and will cause just the same symptoms you are feeling right now...to turn all non-reversible engine codes off you need to replace the sensors the engine codes display or chk why the signal of the sensor is lost. The reversible ones will not activate the limp mode and you could erase them from the ECU by disconnecting the (+) cable of the battery and stepping your foot at the brake pedal for 15-20 secs...


about selenoids...the twin turbo set-up (actuators, boost control, charge control, blow-offs, wastegate...etc) is controlled by an arrange of selenoids and boost/vaccum lines under the intake manifold (the rat nest),... with the single set-up most of it is no longer required and you could disconnect the hoses, but the selenoids need to be plugged to maintain the engine codes off and avoid the slimp mode ....

AImec Racing

also... chk if the MAP sensor is connected correctly and if the chk valve of the connecting hose is not in the wrong direction...

if the MAP sensor itself is electronically bad, the engine code will tell you...

RuSkY RaCeR

the check engine light isnt on, but ill try to run the codes like you said.

ill definetly disconnect the battery and press on the brake..... that fixed the car when i first got it (when i first got it, the engine wouldnt even rev past 3k), but by replacing all the grounds, and putting some new ones on, replacing spark plugs and wires, and by pressing the brake with the battery disconnected fixed it.

thats a good ideal, ill check that now.... maybe it will get fixed, but ill definetly buy an EMS.. (which EMS should i get, i now know that the power fc is good. is there anything better?)

thanx alot guys

RuSkY RaCeR

one more thing.... there is a blue plug that i cant figure out where it goes... its right by the gray plug that went to the airpump. should it be plugged in somewhere? all the rest of the plugs on the solenoids in the rats nest are plugged in...

maybe that blue plug should be plugged in somewhere, but i dont remember unplugging it, and cant find it on the electrical diagrams.

Manolis_D

iTrader: (2)

Dude you need to go talk to somebody at a shop before you go tearing into all this stuff... or do some serious searching through the forum. Buying an EMS isn't going to magically make all your problems go away! Who's going to wire it up? Who's going to tune it? What are you going to do about the sequential setup?

AImec Racing

that blue plug sounds like the egr control valve, if your car is '94 it should be connected to the egr (you can leave it hanging somewere)... also all the air emissions system should be plugged as well....

but again, chk the engine codes first, if the problem persists, it could be the engine harness and i woudnt mess with that unless you find one on eBay...

anyways...i strongly recommend you to find your problem now before upgrading to EMS... if the problem has nothing to do with the ECU, then you will add more variables to the scenario and could be worst...

it took 2 months for me to find a similar problem root cause but i made the car run w/single turbo @12 psi with no ESM and stock fuel system withou any problems....

my problem was the harness... the knock sensor cable was making contact with the oxygen sensor (they run together inside a heat shield)... i didnt get engine codes because the feedback signal to the stock ECU was lost due to the contact... and the control signal voltage for the knock sensor operation was wrong and making the car going limp mode.... the contact was caused by harness overheating caused by me getting the car to the shop w/o the downpipe... it suonds cool now but it was a nightmare trying to findout the root cause....it took me a lot of research but with this kind of car it's VERY WORTH IT to know about it... so as before, do your research...it will be a lot easy if you know what you are doing... so keep going and don't worry,,,,you'll be fine...

RuSkY RaCeR

ok thanx alot. im going to check the engine codes now. my car is a 93 on paperwork, but on the door panel it was made in 92, i dont know if that helps.

also the air pump is off because the turbo doesnt fit with the pump there.... that is why the air pump plug is disconnected... is that a problem? (the directions have the air pump off) the tubes are plugged up that went to the pump.

also where is the knock sensor located? because the turbo got the engine bay hot a couple of times just by idling before i put a heat shield on it. and if the knock sensor is by the oxygen sensor, it could have gotten overheated or something


thanx

GoodfellaFD3S

iTrader: (213)

knock sensor is on the driver's side of the motor, nowhere near the turbo.

AImec Racing

the sensor wires run together into the harness, not the sensors... the knock sensor is at driver side close to the trailing plugs (upper plugs) ....