Ignition Switch, Main Relay or...?

[CDX_NSX]

Part of this problem cropped up a while back. It went away and came back today.

First incident: Took the car to the gas station and after filling up, the car wouldn't start. It will crank, start, but die when the key was released. I was able to keep it running by revving it a bit. This occurred during a time when I was having other issues which I attributed to bad gas (issues went away after I topped up). The starting problem also went away after that.

FFWD a couple of months to today: Car starts up fine. I take it out for a drive and head to a location about 20 miles out. Get there, get out and back in the car within 2 minutes. I start the car, and it starts and dies. Start it again, and it stays on (no revving), but the dash lights are dimming and the speedo and tach and dipping to zero. I rev it a little. The tach holds and I take off. After about a minute of driving, I come to a light and as I slow down, the speedo and tach start dipping to zero again; all this time, the car is still running without a hiccup. I then begin to drive home with my fingers crossed hoping to make it before the car dies and won't restart. I got home with no issues.

Upon arriving home, I decided to test it. I tried to start it, but it would again start and die upon releasing the key. It would only stay running if I revved it up.

So I shut it off, came inside and typed this up.

Here are my thoughts: Starting and dying when the key is released indicates to me an ignition switch issue. However, it seems that revving the engine keeps the car running. If it is indeed an ignition switch issue, I don't see why giving it more gas would make a difference in whether or not it stays running.

If it is a main relay issue, then the car should maybe start and die, but do nothing but crank from that point on. Yet, the car will continue to start and die as many times as I try.

Given all of that, the dimming of the dash lights as well as the dipping of the tach and speedo to zero seem to indicate a power or power delivery issue.

As you can see, I have no idea what's going on.

What do you think it is?

Thanks for reading.

 

[EIFFEL]

Sounds like ignition switch is going out on you.

 

[zahntech]

I vote ..Ignition switch..and here is a theroy about the revving it up ....when you rev it the system voltage goes up and more current flows thru the beleaguered Ignition switch....Just my .2..here's a diag tip for ign switches ..play with the key while the engine is running, turn it just a tiny bit back and forth and see what happens ..good luck


Oh and you may still have a failing main relay at the same time as your Ign switch failure :frown:

 

[CDX_NSX]

Hmm.. OK. Thanks, fellas.

 

[Kitaka]

Hey CDX-NSX

Did you ever resolve your problem? My '93 is giving the same indications although I have replaced the Main Relay (to no avail). From reading the websiste my other options appear to be the speed sensor on the tranny.

 

[drew]

Your speed sensor won't cause the engine to die and the lights to go dim.

What exactly are the symptoms?

Drew

 

[CDX_NSX]

The switch symptoms are more pronounced now, so I'm rather convinced that it is indeed the switch. I'll find out today though. I have a replacement switch ready to go in. I'll let you know.

 

[Joseph]

have you tested the main relay before purchasing the ignition?
I believe its the main relay not the ignition switch.

 

[CDX_NSX]

Hey Joseph, long time no see.

The main relay is definitely triggering the pump. Car starts everytime, but only stays running if the key isn't allowed to return to the ON position. The car will continue to run if I hold the key. I've also resoldered the joints on the main relay just to be sure.

I'l find out soon enough though.

BTW, click the link in my sig.

 

[Russ]

Sounds like the switch to me also. How'd it go today?

 

[CDX_NSX]

Just got done. Yup. Looks like the switch fixed it.

I performed a non-scientific test before and after.

Before I started working on it, I started it up to confirm the symptom. Started it, and the damned thing kept running. So I shut it off and tried again, but this time and each time after, it wouldn't stay running without holding the key.

Went to work switching the switch (really easy, BTW). After I was done, I started it up again and it now stays running everytime I start it.

So, yup. Looks like it was the switch.