NSX starter issues

[Trilapino]

NSX having issues starting. Checked fuses, brand new ignition switch installed 8 months ago, alternator is less than 2 years, when turning key hear starter clicking.

Bought a rebuild kit which includes that spindle and contacts, replaced them both, installed everything back and same issue…clicking from the starter. What else can it be? Do I need to replace the whole starter? Any help is appreciated. Thanks.

Btw car starts fine when push starting or if I push start it. drive for a little bit, turn off the car and turn it back on it starts right away lol

 

[Old Guy]

How old is the battery? It almost sounds like you have a dying cell(s) in the battery and that there is sufficient voltage to operate the starter if you try a restart shortly after running the engine; but, the voltage collapses if the battery sits for a while. When you have one of these 'click; but, no start' events, turn on the headlights. If the headlights go dim while you try to start the car the battery is likely at the end of its useful life. You could also just have the battery load tested (proper big toaster oven style not the little electronic things) to confirm its condition.

It is also possible that the battery post terminal clamps are in poor condition and are making poor contact with the battery posts. This is a fairly common Honda product malady caused by overtightening and stretching of the clamps. Check the clamps to make sure that they are secure on the battery posts. However, the battery clamp problem usually comes and stays and doesn't go away on hot restarts.

If it is not the battery or the clamps then it would seem likely that something is up with the starter. But, I am having a hard time figuring out what that 'something up' might be that works warm; but, not cold.

 

[Trilapino]

I just

How old is the battery? It almost sounds like you have a dying cell(s) in the battery and that there is sufficient voltage to operate the starter if you try a restart shortly after running the engine; but, the voltage collapses if the battery sits for a while. When you have one of these 'click; but, no start' events, turn on the headlights. If the headlights go dim while you try to start the car the battery is likely at the end of its useful life. You could also just have the battery load tested (proper big toaster oven style not the little electronic things) to confirm its condition.

It is also possible that the battery post terminal clamps are in poor condition and are making poor contact with the battery posts. This is a fairly common Honda product malady caused by overtightening and stretching of the clamps. Check the clamps to make sure that they are secure on the battery posts. However, the battery clamp problem usually comes and stays and doesn't go away on hot restarts.

If it is not the battery or the clamps then it would seem likely that something is up with the starter. But, I am having a hard time figuring out what that 'something up' might be that works warm; but, not cold.

Welp I am in shock. As I was diagnosing the issue more in my garage, neighbor comes in my garage and sees that I’m tinkering around. I read your reply and asked him, do you have a battery starter/charger? He brings one over, we hook it up and the car started really fast on a cold start. I’m beyond confused cause I had this battery for only 2 years and it’s a yellow top optima. Time for me to bring this battery back to autozone and replace. Thank you for you recommendation!

 

[Old Guy]

Did you check those battery post clamps? If you jump started from the jump start terminal in the engine bay you by-passed the clamps. If you jump started from the battery post you also by-passed the battery clamps because the jump starter clamps would have grabbed the outside of the battery post clamps.

The NSX has a moderately high parasitic load. If you don't drive at least every 2-3 weeks the battery may have lost enough charge through the parasitic loads to prevent a start. That is not an issue with the yellow top. You need a battery maintainer such as a Ctek to deal with infrequent use. I have a group 35 AGM battery (not an Optima) in my unmodified 2000 NSX and I can go 2 weeks easily without having starting issues. Haven't pushed it beyond 2 weeks.

 

[Trilapino]

Did you check those battery post clamps? If you jump started from the jump start terminal in the engine bay you by-passed the clamps. If you jump started from the battery post you also by-passed the battery clamps because the jump starter clamps would have grabbed the outside of the battery post clamps.

The NSX has a moderately high parasitic load. If you don't drive at least every 2-3 weeks the battery may have lost enough charge through the parasitic loads to prevent a start. That is not an issue with the yellow top. You need a battery maintainer such as a Ctek to deal with infrequent use. I have a group 35 AGM battery (not an Optima) in my unmodified 2000 NSX and I can go 2 weeks easily without having starting issues. Haven't pushed it beyond 2 weeks.

I clamped the jump starter on the post clamps connected to the battery. I’m still having the same issue unless I get the charger plugged in, otherwise after a full day or couple of hours it won’t start on its own. I replaced the battery just cause I had warranty cover just cause and that didn’t help of course. Something is cause a parasitic hold somewhere and I can’t figure it out. I’m almost giving up and just take it to a local shop

 

[Old Guy]

Did you confirm that the cable clamps are grabbing the battery post tightly? Try twisting the clamp by hand. When the clamps fail the clamp bolt can by fully tightened; but, the clamps still remains loose on the post.

If you have a multimeter, with the car parked and everything shut off, remove the ground cable from the battery negative terminal and connect the multimeter (on its current measurement setting) between the negative battery terminal and the ground cable. You should read about 0.07 amps or less (70 milliamps) with everything shut off (doors closed). If you are killing your new battery in a "couple of hours" you have to be way above 70 milliamps and it should be really obvious that something is on. Do you have any aftermarket stuff on the car?

 

[Trilapino]

Did you confirm that the cable clamps are grabbing the battery post tightly? Try twisting the clamp by hand. When the clamps fail the clamp bolt can by fully tightened; but, the clamps still remains loose on the post.

If you have a multimeter, with the car parked and everything shut off, remove the ground cable from the battery negative terminal and connect the multimeter (on its current measurement setting) between the negative battery terminal and the ground cable. You should read about 0.07 amps or less (70 milliamps) with everything shut off (doors closed). If you are killing your new battery in a "couple of hours" you have to be way above 70 milliamps and it should be really obvious that something is on. Do you have any aftermarket stuff on the car?

After tinkering around the battery clamps, your statement is true about not carrying enough current. I moved it around and re-tighten and haven’t had an issue since. I’m going to replace them since they are really beat up. Will update when clamps are upgraded!

 

[Wild Turkey]

I'm quite interested in the clamp replacement; please post pics. I remember seeing some pics somewhere but my search isn't popping. I've seen NSX's with shims between the posts & the clamps to get better contact.

My '01 clamps seemed much better than those in my '95, but @Old Guy says his 2000 were made of recycled soup cans, so I expect they never changed to a better standard over the years

My clamps seemed perfect when I last changed my battery, but I went to a LiFePO4 battery with terminals, which I had to add converting posts to. Since the OEM clamps are questionable quality and a known failure point, I'd like to switch my clamps to something higher quality, that would also connect straight to the terminals without the conversion posts and clamps. Anyone aware of a good supplier for this? The -ve cable can be changed entirely I think, but the +ve will need a new terminal.

 

[GGawaran]

@D Baggins built something custom that looks like a great upgrade. I'll try to find the thread and link it here @Wild Turkey

 

[Old Guy]

I'm quite interested in the clamp replacement; please post pics. I remember seeing some pics somewhere but my search isn't popping. I've seen NSX's with shims between the posts & the clamps to get better contact.

My '01 clamps seemed much better than those in my '95, but @Old Guy says his 2000 were made of recycled soup cans, so I expect they never changed to a better standard over the years

My clamps seemed perfect when I last changed my battery, but I went to a LiFePO4 battery with terminals, which I had to add converting posts to. Since the OEM clamps are questionable quality and a known failure point, I'd like to switch my clamps to something higher quality, that would also connect straight to the terminals without the conversion posts and clamps. Anyone aware of a good supplier for this? The -ve cable can be changed entirely I think, but the +ve will need a new terminal.

Your battery clamps may be just fine depending on their treatment by previous owners. I had a 2003 Honda Pilot with the exact same soup can battery post clamps as my NSX and they were just fine when I sold the Pilot in 2021 because I did not overtighten them. The shims are a temporary bodge. You need shims because the clamp has stretched and once it has stretched it is probably on the way out. If the clamps are tight on the posts without shims they are probably just fine and unless you have corrosion issues I would be inclined to leave them alone.

There are lots of ways to fix failed clamps, some of which have more bling than others. My fix was decidedly low bling.