1.3mazda

so this is what is going on........a jdm 13bt was bought off ebay, turns out wiring is completely different and the ecu and wiring isnt capatable with the STOCK 87 S4 non turbo car i am putting the jdm rotary in! so i just want to know if i purchase S4 turbo ecu, engine wiring, mass air flow, boost sensor, will it work on the Jdm motor i bought (basicall short blocking the japenese motor and using US ecu and wiring and fuell managment componets,) if i am missing something please let me know!!!

ps............also, is there a compressoin ratio difference between the S4 turbo motors and S5 turbo motor????

HAILERS

Buy the series four ECU like a N332 or N333. DO NOT BUY THE SERIES FOUR TURBO HANESS. Use your n/a harness.

You NEED to also buy a turboii, series four, boost sensor and afm to go along with the above. The engine will start and run with the na boost/pressure sensor and afm ............but not right imveryhubleopinion.

TehMonkay

iTrader: (-1)

yeah S4 is 8.5:1 S5 is 9.0:1

You can use an NA harness with a turbo ecu maf and map sensor, i think you might have to change 2 wires.

1.3mazda

bump for knowledge

1.3mazda

i planned on buying the n332 S4 Tii ecu, but will this be possible beings that the engine i am using i supposedly a S5 JDm motor (if that true and its true that it should be 9.0:1 C/R) will the S4 Tii ecu work (it runs an engine that uses 8.5:1 C/R)!!!!! any advice??

1.3mazda

bump

1.3mazda

so does any1 know??? if i use a n332, i am going to need fuel injectors from that system too wont i ???

HAILERS

It'll work just fine, the ECU.

The injectors. Depends. Get your meter out and look at the resistance of the injectors in your present car and then measure the resistance on the injectors of the NEW engine.

Low impedence would be injectors showing something on the order of 2-3 ohms.

High impedence would be injectors showing something on the order of 12-13 ohms.

If the old and new engine injectors are the same, no action taken.

If the old is 2-3 ohms and the new 11-12 ohms.......gotta do a little something. Not much of *something*. That would mean your car has a *solenoid resistor* package on the EM harness. Just remove the *solenoid resistor* package. Cut ITS pigtail harness in the middle and put the resistor package on the shelf in the garage. Take what's left (the plug and five wires) and solder ALL FIVE WIRES together and cover with shrink tubing to prevent short. The reconnect that plug with the five soldered wires back on the EM harness. Done. Or if you have a GOOD electrical crimper, crimp all five wires together in lieu of soldering.

1.3mazda

problem, cant remember ohms for the injectors from the N326 setup????? but anyways they were only 460cc so they wont work ( the car was a N/A) and now i am putting in S5 Jdm turbo motor and just want it done asap!

1.3mazda

isnt S4 turbo models equipped with low impedance injectors (550cc)??

HAILERS

Yer not catching on. Whether turbo or non turbo 86 and early 87 had low resistance injectors. Later models had high resistance injectors.

Late 87 and on have high resistance injectors. 87 and on meaning 87 1/2 thru the series five etc.

It's not hard to find out what your car had. Like I said, about a foot below the afm there is a aluminum covered device called a Solenoid Resistor bolted to the frame/fender. It would have five wires on it going to a large round plug that connects to the EM harness. IF it is there, then your car had low resistance injectors. IF it is not there, AND the EM harness in that area has no large round plug with five wires going to it, then your car probably had high resistance injectors like all 87 and newer cars did.

EARLY series four turboII cars had low resistance 550 injectors, yes. So did EARLY non turbo cars, but they were 460's.

Buy a HAYNES or DOWNLOAD the free FSM from this site and look at the FUEL AND EMISSIONS section of the FSM. OOOps. The FSM is a 88 and won't show the Solenoid Resistor. Haynes will though.

HAILERS

At the bottom of the attached thread I posted a jpg of the solenoid resistor. Unfortunatly I jpg'd the bottom side that bolts to the frame/fender. Plug and pigtail will look the same though. Might read NZCONVERTIBLE'S words on how it works and why it's there.

https://www.rx7club.com/forum/showth...enoid+resistor

1.3mazda

okay, so i guess this is my question, if i am going to use a S4 Tii N332 ecu to get out of the JDM bullshit N374 ecu, then do i have to use low impedance injectors and injector/solenoid resistor pack with the N332 ecu or can i use high impedance injectors??

HAILERS

Actually the N332 or N333 series four ECU has close to nothing to do about if you use high or low.

EVERYTHING depends on if the harness that attaches to the engine, the EM harness, has or does not have a SOLENOID RESISTOR PACKAGE on it or at least the plug on the harness for it.

The solenoid resistor package adds 6 ohms to the circuit going thru the injectors to the ECU. Thatls for cars with the low impedence injectors on an early car.

Cars without the solenod resistor have no extra resistors inline and depend on the extra impedence of the injectors themselves. I.E. they are of 12-13 ohm resistanve all by themselves.

Bottom line: YOU need to ohm out the injectors on the new engine to see if they are 12-13 ohms or 2-3 ohms. IF 2-3 ohms, then you NEED the harness with the Solenoid Resistor package OR install some 6 ohm resistors inline with each injector wire.

1.3mazda

cool, that should keep me busy into tonight trying to get it ready to start and run with boost thanx a lot!

myersprostatus

iTrader: (2)

i just did the same thing you did....

i bought a s5 t2 engine and i have a 86gxl i plan on putting it into.

i wish they would have stated in the faq that you needed the s4turbo ecu if you plan on putting a s5 turbo engine in...

ahh more money more money..

everyone always bitches to people look at the faq look at the faq turns out some forums are actually needing to be recovered...

myersprostatus

iTrader: (2)

and i also read on rotores that with the s4 n/a harness on a the s5 engine, the harness doesnt work for the tps, valve, etc. etc.

anyone know?

is their a simple wire switch easy fix? or what? please help, getting engine soon

1.3mazda

yeah.....run S4 tps,afm,boost/pressure sesor,fuel injectors(only if u have a low impedance fuel injectors and a fuel injector resistor pack on your EM harness)

1.3mazda

^^and thats at the very least i think!

1.3mazda

damn almost forgot S4 turbo ECU!

myersprostatus

iTrader: (2)

okay cool, not really that difficult then.

1.3mazda

^ forgot to tell u that if you do it that way then u have to premix your gas with 2 stroke (i like valvolin outboard motor blue bottle oil), if u dont want premix your gas than u have to get S4 front cover with S4 OMP (make sure you get turbo omp)and S4 OMP LINKAGE and S4 waterpump w/housing and S4 t-stat housing, also S4 throttle body! i think thats all.

myersprostatus

iTrader: (2)

premix : /

looks like im gonna be emptying my wallet.....

damnit

myersprostatus

iTrader: (2)

1.3mazda
is your swap project running yet?

i guess i can ebay all the parts cause i really dont wanna run premix

theres no complications with the mixture between the s4 pump/housing/ ,omp, throttle body, etc, right?

myersprostatus

iTrader: (2)

where did you get the info on how to prevent premix?
general knowledge or forum/site?

if so could i have link?

i relaly odnt want to buy parts that i end up not needing