Ok so i wonder how many volts you should get from the CAS test points when you crank.. Ohms test out but... No start..

has anyone hooked up a voltmeter to the points and cranked... You should get something...

It should be close to this in this video.. i am thinking..
Or can someone just hook up theirs and crank and tell me what they get..

http://www.youtube.com/watch?v=6ws8EVQ6NjE

 

I have used a digital storage oscilloscope on the mazda CAS before. Not on a engine during cranking however.

 

Have you checked if the fuel pump works w/key to start or just key to on or both?

 

And does your vref voltage indicate 5 volts w/key to on from pin 2A or from the Brown/White wire at either the TPS, Pressure sensor, Variable resistor?

And did you ever check for error codes?

 

The CAS has VR sensors in it. The output is AC. Output ranges from millivolts at cranking speeds to high voltage at high RPM. You won't see the output on a VOM. You'll need an oscilloscope to see the output. There is no voltage input. There are two grounds and two outputs to the ECU.

Turn the key on and spin the CAS by hand. You should hear the injectors click. If you have the plugs out, grounded to the fender or intake, and wires attached to them you should see spark.

 

 

ludwig is right in what he says

 

Ok i messed with the cas and checked everything.. I also found a plug by the ECU that i did not know what was.. it has a connector on it.. that dose not have wires... it terminates there..

Any ways.. i think i had messed with it all this last week.. then it did not start.. so i had to move.. so i have been moving since saturday.. the last thing i was going to do was get the car to the new house.. and after a lot of prayer.. and messing with it all.. it started tonight...

it is not running right for sure... so after it smoked every where.. i drove it for 30 minutes...
i turned it off.. and when i went to start it.. it does not start.. i have to put the petal to the floor.. but once started its good...

So i guess i have to tune it.. after it warm.. right.. Bypass wire and tune.. but my whold 3500 rpm start up is gone.. for warming..

 

I know on my car if the high rev cold start engages that just a touch of the throttle will stop it so since you have to press down or perhaps pump the gas pedal to get the car to start it might prevent the warm up cycle from engaging. Also, it only works when the car is cold started initially and the coolant temp has to be above a certain threshold and if the BAC were disconnected or not working properly then it won't high rev as well.

 

So how does the BAC keep it from the warming cycle? .. if thats what you are saying..

 

Because the Air Bypass Solenoid works in tandem w/the BAC. If the Air Bypass Solenoid were disconnected and the BAC operable it would still go through the high rev process during a cold start under the necessary conditions.

 

So the BAC puts the car through the high rev warm up process. ?

 

You could say that or more precisely you could say it "assists" in the process.

 

I am looking through all my BAC , Air Bypass solinoid and the type for now.. to see whats up..

I was wondering about the fast idle adjusting screw.. i am not sure if my 86 na has one.. its just the one on top... for mixture?

just wondering any way..

 

The high rev start up is not supposed to work each and every time you start the car in case you thought otherwise.

If your car is truly cold started and the temp of the coolant is above sixty degrees or so and your high rev start is not kicking in then it might be because of the thermoswitch at the bottom of the radiator is not working properly or the Air Bypass relay located in front of the passenger headlight is not up to speed as both these items are part of this particular system or the car is being started in neutral and so on.

The fast idle screw is located behind the throttle body by the fast idle cam and it dictates the rpm of the car when it's cold started and the high rev start up has gone through its 17 second cycle. The fast idle is for what happens "after" the high rev and not during.