bmwrx7man

iTrader: (2)

well today is the first day of me cranking up my car and getting her running . before i start i did the rebuild myself . car was running mint before the front apex seal went on old motor . it did have hot start issues but not all the time . sometimes i would let it sit for 5 mins then it would start up if i keep it floord this is before the rebuild .

new rebuild has:
ra super seals 2mm , mazda apex seal springs new , mazda corner seals side seals etc . everthing is mazda besides the super seals and gasket kit . rebuild was done on 2 used rotor housing with barley anywear and both rotos were replaced with ones that had 42k on them very clean .

for mods the car is all stock besides front mount and BNR stg 4 s5 turbo , all emissions removed besides bac vavle .
today is got a new battery all new fluids fuel lines etc ...

i got her started first 10 secs of cranking she started right up no problems. let it warm up "was idle high till it got warm " thermostat was bad cause i noticed the hoses building pressure so now im running with no thermostat , cars is half way temp no problems now . i shut it off quick because the coolant light came up ..so i went togo add more coolant. and bamm she wouldnt start AT ALL . felt like she did a few times but nope . crank crank crank . i pull the fuse out and crank for 10 secs to unflood bamm she started up stayed idle . i shut if off 5 mins later to restart and bamm no start again so i had to deflood for it to start . i let it sit for 1hr to get cold and went outside to start it . she started right up 800rpms steady no problems left it on for 5 mins shut it off and restart to see of it would start and it started right up . mind you this is while it was cold . needle for temp was maybe 1/4 way up..

now for the full warm up impossible to start issue . do i gotta rewire the fuel pump now? something i reallly didnt want todo . should i bother changing the temp sensor? car is on stock fuel system and ecu for now still i get my injecters and rtek .

AGreen

iTrader: (11)

Check the coolant thermosensor, which is behind the upper coolant neck. In all reality, the sensor is probably ok, it's most likely the sensor wiring. It's MUCH easier to check the voltage at the ECU. Pin 2I (it's green/white) should have between 0.4v and 1.8v when the engine is warm. There is really no other way to check this unless you have a Mazda readout box that is archaic at the least. I understand most people are afraid of electrical stuff, but it really is simple. The red lead on the multimeter goes to pin 2I, the black lead goes to a good ground.

Get a copy of the FSM from www.rotaryheads.com and get at it.

And congrats on your first rebuild.

marclong

iTrader: (1)

Check the shift key first.

bmwrx7man

iTrader: (2)

what u mean shift key? and thanks a green theres no way to test the ohms outa the car? thats how i did it on my civic

satch

iTrader: (1)

The FSM illustrates how to test it out of the car if need be using ohms.

bmwrx7man

iTrader: (2)

i dont see that sensor at all in the fsm . for s4 . unless im going crazy almost went threw every pdf

satch

iTrader: (1)

Should be in the Fuel and Emission section.

Diagram on page 4 and the testing info on page 46.

https://docs.google.com/file/d/0Bzy-...TBi/edit?pli=1

bmwrx7man

iTrader: (2)

got it..i doubt its the sensor tho...

AGreen

iTrader: (11)

Like I said, I doubt it is the sensor. The voltage test will tell you EXACTLY what the ECU is seeing. And it's MUCH easier to read the voltage at the ecu than removing the alternator and draining the coolant to ohm the sensor, which will only tell you if the sensor itself is good or not. Pull the passenger's side door sill plate, pop off the passenger's side kick panel, pull the carpet back a little, take off the 2 10mm nuts and 2 10mm bolts that hold the ECU kick plate on, and tap in to pin 2I to ground. As stated before, pin 2I will be a green/white wire, and under the fuel/emissions section of the FSM, it gives you a road map of which pins are where on that connector. If you're reading 0v or 5v, then there's an issue that will probably result in the connector on the coolant sensor being bad.

bmwrx7man

iTrader: (2)

i need to get my hands on a meter now . but the car starts up fine everyday i havnt put anymiles on it . 0 miles and has been ran for like 1hr or more. when its hot and i shut it off dont wanna start no more at all . so im gonn ahave to make a fuel pump switch . herd this is caused cause of rebuilt motor needs more break in. after its broken in im going to ge the 750cc injecters all around and the rtek 1.8 thats about it lets see if that helps

joeylyrech

iTrader: (11)

Low compression!Is a new rebuild with used housings and is normal for them 2 start right up when they are cold and not when they are hot,you have 2 start driving the car and that should help.If them problem continue after a couple hundred miles something is wrong with the rebuild and it will not build enough compression 2 start when hot so your only options are fuel cut off switch and deal with it or another rebuild so lets pray that it will get better when you start driving it.Stage 5 bnr with stock injectors is not recomended,dont try 2 boost or go wide open cause your motor will die.

bmwrx7man

iTrader: (2)

no no im only leaving the injecters in so i dont temp myself to boost. im not gonna boost at all for 500 miles im turning the boost down allll the way . once i get over 500 miles then ill put the rtek n injectors and do low boost pulls and wait till 1000 to fullly get on it .