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Not just another EPS question

Joined
22 April 2014
Messages
354
Location
Greenville, SC
I have a '95 NSX. Today the EPS light came on and the EPS stopped working. I parked the car for a bit but the light was still on and EPS was still not working when I restarted it. When I hit the gas from a stop light, it hesitated a bit like it lost power for just a second. I took it home and drove another car to work.

Tonight I pulled the clock fuse and waited about 30 seconds. When I plugged it back in, there was a bit of a spark. When I went to start the car to check if the EPS was reset, i noticed that no dash lights came on. When I cranked it, all the lights came on and it immediately died just after starting. I repeated the entire procedure, and it still dies just after I crank it.

Any thoughts? I searched the threads today but didn't find one that addresses this specific issue.

Thanks for your help.
 
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It's a system very sensitive to voltage. Can you charge the battery, clean the battery ground connections, check the battery clamps, and maybe try a new battery?
 
Sure can. From the records, the battery was last replaced about 5 years ago, so it might be time. But would that cause the car to shut off just before starting?
 
I know from personal experience the ignition switch powers a lot of the systems, and can cause the issue you are having with the car shutting off immediately after start. Has your ignition switch ever been replaced? My original had corrosion at the contact points, not bad for almost 20 year old part. Cost me $129 for parts and labor so might be worth swapping it out. Good luck!
 
Oh sorry I wasn't very good at reading. I agree with posterchild2 that the cranks-and-starts but dies-after-cranking behavior is very indicative of a bad ignition switch.
 
No need to apologize; I appreciate the assistance. A quick email chat with Brian K yielded a potential diagnosis of the main relay. Neither the main relay nor the ignition switch have been replaced over the 125k life of the car. So those seem to be a good place to start. I'm leaning toward main relay since it started with the EPS failure.
 
Like the other responders, I would go with the ignition switch rather than the main FI relay as a first choice for the following reasons:

- failure of the main relay will not cause the dash lights to become inoperative
- if the engine started when the key was in the crank position the main relay has to be operating
- the engine starting when the key is in the crank position; but, stopping when it is switched to the run position is a classic symptom of the run contact in the switch failing
- the main FI relay has nothing to do with the EPS. The low voltages resulting from a bad contact in the ignition switch can bugger up the operation of lots of stuff

The service manual has a test procedure for the ignition switch so that you can confirm that it has failed. There is a .pdf of the service manual in the wiki if you don't have one (unless you have ready access to someone like Larry B. everybody should a manual if you are going to retain ownership of a car that is entering that 'certain age thing').

Replacing the main relay won't hurt and they are relatively cheap if you source from Rock Auto. But, they are also easy to check and repair. The failure is usually caused by solder failure. There was a recent post on PRIME covering repair of the relay.

Also, can't hurt to check the condition of the cable battery post connections. People tend to over tighten the cable battery post clamps which stretches the clamp with the result that the clamp no longer grips the post. This results in a bad connection and voltage problems. If you can twist the clamps on the posts the clamps are probably due for replacement.
 
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eps

i've had my eps fail from both the ignition switch and the speed sensor
 
Thanks for the input. I didn't want you to think I'm ignoring the advice. I ended up working all weekend so I couldn't spend time with the car. I'll let you know what I find once I have the opportunity to work on the car.
 
Soooo...

I thought about getting a new battery but decided to charge the one I have first. It didn't make a difference; it still dies just as its starting.

On to the main relay! I took off the upper back panel and confirmed that the main relay is not there on my '95. There is a vague reference to removing more, larger pieces of interior trim on the Wiki page, but nothing too specific. I have gone through the service manual posted here but could not find it either.

Bottom line: I would appreciate it if someone could either let me know where it is and exactly how to get to it OR point me to the right section of the service manual.

Thanks!
 
You can see the main relay location at p. 11-4 or, better, p.23-10 of the 97+ manual.

You can see how the "Rear Side Trim Panel" is removed at p. 20-38 of the 97+ manual.

Once you remove the full-width upper panel and the square flat panel, you have to remove three screws from the inboard edge of the curved panel and then pull up the rubber trim at the back of the door opening, where you will see the clips that are part of the curved panel and hold it in on its outboard side.

Also:
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Problem Solved. As a refresher, no dash lights would come on when I initially turned the key. When I turned it all the way to crank it, all the lights came on and it immediately died just after starting. I have all records from the day the car first rolled off the lot, and neither the main relay nor the ignition switch had ever been replaced.

It turned out to be the ignition switch. I didn't bother to clean it since replacements were less than $70. I first replaced the main relay, but that didn't work.

One lesson: In the future I am going to order most parts from my local Acura dealer, since the small savings was not worth the delay to me.

Thanks to everyone here who chimed in to help. And a BIG thanks to Mitch and Chris C. for their hands-on help (yes, I'm that incompetent).
 
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