I have a 87 FC GXL N/A 5speed S4 with 72K miles. the car is very difficult to start, takes several trys. The engine cranks, it just seems like there is no spark or fuel.
At first i was thinking it was the fuel injectors or the fuel pump.

It has randomly shut off a few times, idling when parked, at a drive-thru, at a red light, at a stop sign then had problems starting back up. My mechanic checked it out and found that there is no spark at the top coil/igniter near the clutch master cylinder. Its not impossible to start the engine, when it does start it seems to run smooth and ok but rich. He still has more tests to do.

is it possible the CAS is bad?
can the CAS, idle R/L mixture or anything be adjusted?
bad fuse or wire connection?

any help will be greatly appreciated

mods for the engine:
hks intake
corksport header
idemitsu 10w30 oil
corksport catback
mazdatrix CAS angle cover
spark plugs are less than a year old
battery is brand new
thank you very much, joe

 

It could be because of something at issue w/the Main Relay. This relay has two plugs. One plug has four wires. Focus on this plug. Start by removing this plug and jumper the Black/White wire to the White/Blue wire and the Black/Green wire to the Black/Yellow wire. Then try to recreate the situation where the car just dies when idling for example. If the car still dies then immediately check for constant voltage on the White/Blue wire as well as the Black/Green wire. If battery voltage is not present on either or both of the wires then check for a loose connection where they both come from, which is the bottom of the Engine Fuse box. Also, when the car dies check to see if the wipers and turn signals work w/key to on. This will tell you if there is a problem w/the ignition switch receiving voltage. And of course you will want to check the compression on both rotors.

 

u mean the fuse box next to the clutch pedal? and when the car dies all the electronics still work. and i think my car doesnt have relays, only fuses. my mechanic tested the leading coil/igniter and got no spark when cranking

 

There is a fuse box near the leading coil. There is a pic of it in the FAQ section. Also, the Black/Yellow wire at the leading coil must have battery voltage w/key to on. W/o it the coil cannot fire.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/frequently-asked-questions-2nd-generation-rx-7-faq-fc-494667/

 

is it unlikely that trailing coil/igniters stop working?
also if the CAS is bad will that cause the coil/igniter to malfunction?
thanks

 

In a post you made you said the leading coil was not working but in another post you mention the trailing coil. If the coils are not powered by the Black/Yellow wire then they will not work. The B/Y wire gets power from the Main Relay. If there are issues here the car stops running. And the CAS plays a role in the firing of the coils.