1989 Na car,S4 motor, S5 manifolds and turbo, NA harness,no emissions,FMIC,3"straight pipe,JDM chipped ecu( used to run bigger turbo and injectors),N318 pressure sencor,JDM s5 AFM,720cc secondaries w/ wired in resistors,no boost gauge.

motor starts and seems to run fine,drives fine at low speeds,when i give it some gas it boggs out and i havent noticed the turbo spool once.its like when the turbo should start to spool it looses all power.the turbo looked to be in fine shape.

any ideas would be much appreciated THANKS!!!

 

uh, you need a TII wire harness and TII ecu if you are running a 318 boost sensor. believe me, i needed one too after i did the same thing you did.

 

Damn i have another TII one not shure the # its s4 but it was soaked in water for a week or two you think its salvageable?

 

Oh nevermind the n318 is my s4 one i have a n370 i think but it was sitting in water.

 

just get the connectors cleaned up real good. use a thick sewing needle to swipe inside the metal connectors to get any possible rust out. doubt they rusted though, i believe they are stainless.

in order to run the turbo setup properly, you need the following:

t2 ecu
t2 engine wire harness
t2 boost pressure sensor
t2 throttle sensor
t2 mass air flow sensor
t2 fuel injectors
t2 fuel pump or fd fuel pump
t2 knock sensor
t2 fuel rails with stock or afterkmarket pressure regulator (if aftermarket, make sure you get at least 55-60 psi on it)

 

Lies.
You don't need knock sensor, or tii harness. Or tii arm. But you do need to match the pressure sensor to the ecu. N370 is the one you need.

 

Did you rewire the fuel pump? Also what rpm is it stumbling at? Afm* not arm.

 

I can't remember if you mentioned it in your PM, but the ECU you have is in fact a chipped N374 ECU (j-spec turbo), right? If so, do like 2slow4stock suggested, and ditch the N318 (S4) MAP sensor for an N370 (S5) MAP sensor to match your ECU. S4 and S5 electronics can't be mixed.

There's no need for a TII harness in any turbo swap.

 

actually..............n318 is the sensor number and the wire harness grounds differently and also the tps is wired differently. i took one apart and they dont match up 100%

 

also, i have a friend that runs a performance rotary shop and he even told me that to run a turbo setup on an n/a harness, you need to be able to program the throttle and air/fuel mixture.

 

Stop posting garbage. NA and TII TPS are wired the same. Look in the FSM.

Your friend doesn't know what he's talking about, and an N318 is an S4 MAP sensor.

N370 is S5 TII: http://www.mazdatrix.com/getprice.as...m=18-2110-N370

 

Ok so i installed the n370 pressure sencor and that same problem.i dont have to be driving if i step on the gas it falls on its face.if i slowly or normaly accelerate its fine.

 

Its a s4 motor with all s5 manifolds exct.except the coolent sencors on the water pump housing.i havent hooked up the temp sencor that sits intop of the housing.i also had to wire residtors on the 720cc's.

 

marley.. i have a random S4 turbo ecu right here... if you need it i got you. it's dry, been kept inside, and it is my old one straight out of my car worked properly.

 

ok then. so here is a question:

if some sensors match up, then if the car has "all" TII parts installed, does it need to have a TII wire harness as well?

 

Hey Marley this is Damien. I'm not sure if any of this would mater and you know I did the swap S5 engine to S4 body. I'm not sure how the Lower Compression Rotors from the S4 would have any conflict with the S5 ECU and all. Some may wanna flame me but it is a honest question cause this is my 1st RX7, but I'm not new to cars by a long shot...

 

Damien that makes sence but i realy hope thats not the problem

 

As long as the electronics match you're golden. I'm running an S5 TII in in a S4 n/a car with S4 TII ecu and electronics and it runs great. And you definitely don't need a TII harness, it's easier to do it with the n/a harness.

 

Make sure your injector connectors on the secondary injectors are on tightly. What kind of resistors are you using and is the ECU tuned for them?

 

i know he had large RC injectors i dont know what size or what rezistors.the only thing i know about the ecu is it has a mitsubishi relay attached to it thats not hooked up and it has "boost up"writen on it in sharpie.

my friend just scolded me cuz im using 89 gas and i havent checked the timming.he said it could be knocking and eating my timming? he also said "it could be the TPS but id better put 91 gas and check the timming asap!" :/ oops.

 

i just droped in a s5 TII fuel pump. and it falls on its face only when i step on it not when i ease into it like normal. but the turbo never spools.

 

check engine light when this happens?

 

no check engine light.

 

So from mu understanding s5 chassis s4 motor..
But n374 ecu, and s4 tii pressure sensor.

Are you sure secondary injectors are firing?

 

this may be unrelated but alot of fds have 3k hesitation and its because a lack of grounds or the battery cable to the engine being gunked up. maybe add a ground to the chassis and check the cables if all else fails