spark issues, stumped
 

here goes,
got a FC NA and it turns over with a pumping sound. does not start.

I pulled the plugs, set on shock tower, turned car over, no spark, until the ignition returns from the start to on position. then I get one spark.
I check the CAS resistance- in spec
check the trailing and leading coil pack resistance - 160's in spec
stumped here so I decided to see if it was getting fuel. yes, fuel is going to the motor.
I tied the de-flooding techniques, no prevail.....

headed to bed, gotta work tomorrow night

thanks,
Aaron

For starters, S4 or S5? And has the ignition/spark ever worked properly on this car?

W/key to on do you have 12 volts at the Black/Yellow wire at the coils (lead has one but trailing has two of these wires)

Go to the TPS. On an S4 check the Brown wire w/key to on and it should have 5 volts. On an S5 check either of the two Brown/White wires and either should have 5 volts w/key to on. If they don't then something is shorting out the voltage and the car will not start.

Ill check that when i get home in the morning.

I went to check it here before work, and I left the Ign on through out the day, i have it back on the charger.

I just picked this car up yesturday, and he said that he had it running 4 weeks ago. he was not able to get it back running yesturday, Discount!!

NEways, the car is an 88, how ever he claims to have put a rebuild motor in the car

not sure if the moter is S4 or S5

here is a pic of the engine bay:

Attachment 659924

I Have the Haynes manual for it, and went through its checks on the ignition system. could it be that the starter is pulling the voltage down while starting, then when i let off the key it comes back up for 1 spark....


.

Throttlebody is that of an S4. Low voltage can certainly hinder the car from making spark. Make sure you test the Brown wire at the TPS as previously suggested.

I check the coils voltages. 12.7vdc
Check tps wire 5.1vdc

Tach is not moving when cranking...

From what I'm reading the CAS / CAS wiring might be a problem. I'll dig into it

Wish I had a nice wiring diagram to help ring out some wires. :)

Foxed.ca - Mazda RX-7 Manuals

The tach receives its signal from the trailing coil so you might want to focus on that aspect. Make sure the coil is bolted firmly to the fender or the igniter within the coil will not work. Also, there are bullet connectors at each of the coils. These connectors are short lengthed wires which connect to nothing. Jumper these two wires and the tach will then use the lead coil for its signal. See if this makes the tach move or not. A better way to check the coil would be to pull a plug wire off of the lead coil bore and then place the wire right up to the bore leaving a fraction of an inch between the two and then turning the car over and try to observe any spark. If this doesn't pan out then check the CAS connection and make sure it is clean and solid. And do you happen to have a spare CAS as this would help in determining the cause of your problem.

No spare CAS.... i also noticed a squeek/buzz comming from the CPU on the driverside, not sure if that has anything to do with anything.... I have to believe that its either the ECU or the CAS or ECU to CAS wires....

oyvey!

when you turn the ign switch to the RUN position, do the dash/idiot lights turn on... can you hear the fuel pump cycle??? ... what i am getting at is, does the car turn on like it should... do the dash/tail/dome/turn signal lights all work???... does the heater blower motor work... do the power windows , wipers and sunroof work???

second, does the vehicle have an aftermarket security system in it? if so, is it working like it should?


if that all works, you will need to trouble shoot the primary ignition system.
you said you have 12v at the coils, was that checked when the IGN switch was in the RUN position? did you check to see if you had 12v in the START position?

the chances of a bad CAS is slim to none and even if it was stabbed in the wrong spot, you should still see spark at the plugs while cranking assuming the rest of the ignition system was working.


the buzzing CPU could just be the coolant level sensor

disconnect all the rat's nest solenoid connectors along with the ACV connectors and try to start it again.