I've got a 90 RX7 GXL with over 333k original miles. Over the last 6 months or so, I've been having intermittent staring problems that appear to be related to the ignition switch. The problem usually occurs in the morning with the first start. Sometimes, when I turn the key to start position nothing happens. Then. I back-off and try again not turning to full start position and the starter will then engage. I recently bought from Rockauto an ignition switch wiring harness p/n Intermotor US456. The switch part of the harness looks like it's secured to the key switch with one screw. I remember reading somewhere on the web that it's an anti-tamper screw head that's not too easy to remove. Does anybody know if this screw is easy to remove?

 

If you dremel a slot into the screw you could then take it out w/a screwdriver. Also, your problem could simply be the interlock switch which requires the clutch to be depressed to start the car. If you just bypassed the switch it would help tell you what's up.

 

Good point, but I've already bypassed the clutch interlock switch.

 

It could also be the starter cut relay switch. As far as the interlock switch do you remember the wire colors. Reason it is asked is some folks get the clutch switch and the interlock confused as they are two different animals.

Interlock has a Black/Green and a Black/Red wire, clutch has a Yellow wire as one of its two wires.

 

Your point is well taken, but in actuality I don't know. Could very well be the starter interlock relay. I'll just try one possible solution at a time until the problem is solved. My battery is only 2 years old and I replaced the negative cable. I do know that there's been discussions on this board about the ignition switch harness, and apparently Mazda issued a TSB about the ignition switch. The problem appears like it's in the ignition switch. I already bought the switch harness so that will be step one. If that doesn't solve my problem, than I'll next either replace or bypass the starter interlock relay.

So, is there a way to get the screw out without a Dremel? What is the size (i.e., size, pitch and length) of the screw if I want to replace?

 

I believe it's a bolt so there is no slot, which is why you need to make one. Your problem should be easy to diagnose, but you need to test certain things to get a grasp of your problem. Just buying something and hoping it's the cure is probably not the way to go about it. Just find the starter relay, located near the main relay, as it has but one plug w/4 wires. The Black/Blue wire receives voltage from the ignition switch w/key to start. If this wire always has voltage w/key to start then your switch is likely not the issue.

 

all the ignition switches i pulled out had a regular single phillips holding them in, actually.

i know it sounds dumb, but the cylinder housing is the part that has tamper proof screws, since it secures the steering lock mechanism. i guess they figured it was not important to be able to start the car, if you couldn't simply drive away with it.


if the switch doesn't cure the problem, i have something that probably will.

 

Ok...thanks! Good to hear that it's a phillips.

 

So, where is the starter interlock relay located on late 2nd gen? Is it the small metal box that's bolted to the inner fender well next to the clutch master cylinder? This is what I gathered from other threads.

 

Starter cut relay is located next to the main relay which is near the trailing coil. Interlock switch is located on the clutch pedal.

 

So, I finally got around to fixing my intermittent starting problem (see my original post below). This problem was getting worse overtime so I had to take some action. All other related components checked-out alright, which led me to believe that my starting problem was due to the ignition starter switch. My original ignition starter switch had seen better days with nearly 338k miles. I replaced my ignition starter switch with an Intermotor US456 that I bought from Rockauto parts. Replaced the switch and problem solved! Replacing this part made a huge improvement! In addition to solving my starting problem, my idle has has increased by 100-200 rpm and is now solid as a rock, my alternator gauge is steady as a rock at 13.6 volts (used to vary between 12.x and 14.x volts) and my throttle response has improved greatly.

The only problem that I ran into was the small micro-switch for the key reminder warning. Apparently, the ignition switch assembly needs to be removed to replace this micro-switch. I just left it dangling for now. So, I'll need to remove the two break-away bolts that hold the ignition switch to the steering column to replace the micro-switch. I want to replace these break-away bolts with regular bolts. Does anyone know the size of these bolts (i.e., diameter, thread pitch and length)?