Well let me start out by saying im not just some rag tag mechanic, but im not a know it all, and this car is kicking my ***. here is a list of things ive checked

CAS ohmed out good about 150, and i have extra's
ohmed out the wires to the ECU good
Have 12 volts at the coils, grounds good
12v at ECU, and grounds are good
The engine and harness are grounded

Changed the ECU, and it wont start, and im supposed to be driving to Colorado today. REALLY NEED SOME HELP HERE GUYS PLEASE!!!

 

When you tried to "pull codes" what response did you get? I gather you connected a spare CAS and connected it up and spun it to check if you had spark? Did you pull the plug wire(s) from the coil bore to check for spark. If you pulled the plug from your ECU which houses pin 1V and with the key to "on" do you get a low voltage reading or a very high one. If it reads close to 12 volts the trailing coil is damaged.

 

well now i see that my check engine light is not working, so how will i self diagnose?

 

Did the light not work after you used the jumper wire to pull codes or after you "just" turned the key to on? Perhaps disconnecting the negative battery terminal for 30 seconds to reset it might work. Do you have the newer ECU in? If so, replace with the older unit and try again.

 

are you getting spark through the wires? take off a wire sticka screw driver in it set it next to your strut bolt. no metal from screw driver touching the car when you crank it do you see spark arching to the bolt?

do you have fuel pressure?

 

yes i'm getting great fuel pressure, and I'm not getting spark. I have an extra spark plug that i have grounded out to test it. Just no injector pulse or spark

 

definitely need to spin a CAS by hand to see if that does anything

 

Why not hook up another CAS to check for spark and remove the plug wires from the leading coil bores and test them one by one and check if the issue can be narrowed down and unequivocally eliminate the plugs and plug wires. And are your coils bolted properly to the fenders and receiving the "proper" ground source.

 

I tried pluging in another CAS, and there was no spark when i spun it by hand with the key on. I'm also getting power to the main relay. I'm going to try all 4 CAS's i have

 

The light just may be burnt out, cause it was not working before. I know it used to before it sat for 5 years

 

Update. I am now able to get one spark with the MAS disconected, and i shut the key off, and then start again, and only one spark from the leading. I ohmed out my MAS, and its within specs on the MAS side, but i did not check the inlet air temp side of the MAS. Any ideas guys?

 

I pulled codes off of my N370 ECU and its just emissions stuff port air, and split air. Check engine light does not work on the knight sport N374. Could it be my Mass air flow sensor? I'm at my wits end here.

 

Don't know if you tried to pull codes with the key just to "on" but sometimes the codes will only be thrown if the engine is cranked.

 

yeah i know. I cranked it about 3 times so that the ECU would Log the codes. I have a friend that i recently met that has the same car as mine 89 turbo, so im going to take some voltages, and plug my MAF sensor into his car, then maybe the ECU if he will let me. I always appreciate the input man, thanks

 

So i found a relay next to my main relay, that is rusted to crap. Its a 6 pin conector Does anyone know what its for?

 

Could be the starter cut relay. Check the FSM wiring diagram and see if the wire colors match up.

 

I checked the S5 diagram and its the plug for the starter cut relay.

 

That relay must still be functional 'cause you say you turned the engine over with the starter. That relays intermal contacts pass the Start power from the key to the starter solenoid, so obviously that part works. T

That relay only pulls in and seperates the internal contacts IF a THEFT is sensed by the Theft control unit.

Go to your boost/pressure sensor and pull it's elect plug off. Key ON engine OFF.

Now also pull the elect plug off the AFM.

Now Measure the voltage on the brown/white wire of the boost/pressure sensor. Should be approx 5vdc.

Now while measuring that brown/white wire with key ON engine OFF, put the elect plug back on the AFM. Does the voltage stay the same? Increase? Or????????

And as a clue/curiosity ............with all elec plugs connected, STARE at the tach needle. Now turn the key to just ON. Did the tach needle barely bump up just one time? Or not. Try several times to be sure.

 

Motors probably blown, get a new one.

 

I've got a starter triger hooked up to start it, but i have tried with the key just to make sure. I live in phoenix now, so im driving up to prescott tomorrow to work on the car. I checked the reference voltage at the boost sensor, and it was good. I'm so close to getting 5 gallons of RX-7 begone from the gas station...

Motor is brand new

Thank you guys so much for input and help

 

wha?... new motors can still be blown.... [shrugs]

 

Ok so will a turbo model start without a knock sensor hooked up? The wiring diagram shows that the MAF, O2, and CAS sensors are all linked by ground, so... I'm re wraping my harness and installing the knock sensor tomorrow, All the wires ohmed out to 0 or .01 ohm's.