NSX threatens not to start!

[VancouverBCnsx]

If not driven for just a couple of days, my 1991 NSX seems to have a significantly depleted battery. It often requires up to 6 attempts before it starts. So far, with perserverence it has always started even though at times on the initial attempt there is actually very little "juice" getting through (ie almost totally dead...yet somehow it ultimately starts)
There have been almost no mods that would affect the electronics except perhaps for the change of various interior lights to LEDs during the past year.
I had a start up issue about 7 months ago and replaced the battery at that time. While doing that I noticed that one of the battery connections was loose and used a lead cap over the pole to tighten it up. THis seemed to resolve the hesitant startup issue for a number of months. However the situation is definately back.
A few weeks back I exchanged the battery yet again (on warranty), this solved the issue for only a couple of weeks.
Once started and driven briefly, the battery seems to be recharged and any restarts appears perfectly normal.
(There is an installed radar device (put in 20years ago) and an ipod connection in the trunk (installed a couple of years ago)
The voltmeter reading in the dash shows a reading of 14 when the engine is on and 12 when the key is inserted and only the electronics are engaged.

Any ideas as to what may now be drawing down the battery? Thanks

 

[ftuhy]

Unless something is wrong with your gages, the charging and "engine not running" voltages are correct. To me it sounds like a bad connection, really bad luck with batteries, or something is staying on with the car turned off. (The most recent battery lasted 10 years/30,000 miles in my NSX, so this is far from normal.)

There are too many electrical things that can go wrong - from a pinched wire to a failed radio, comtrol module, etc for a simple WAG as to what might be drawing the excess "off" current.

Simple stuff to try (1 & 2 are just good to do, 3 addresses excess current drain):
1. Clean the terminals on your battery cables with a terminal brush (essentially a steel bristle bottle brush). Also, check that the end of the battery cable actually has all the wire in it fastened to its terminal. I've seen the plastic insulator crack and corrosion get inside the cable and eat away all but a few strands.

2. The cable terminals should fit tightly on the battery posts and not require that lead cap for a good fit. If they don't fit snugly before tightening them, then they are stretched way out of shape and should be replaced.

3. A good battery should last at least 3 weeks with the car not being used. A few days says you have something draining the battery. The simplest way (ie, no test equipment required) to confirm that - immediately after turning the car off, remove the cable from the battery ground terminal, and let the car sit for 2 or 3 weeks. Re-connect the ground. If the car starts easily, the battery is good. Of course the bad news then is you have excessive current drain and need to track it down.

At that point, get an ammeter and place it in series with the battery ground terminal cable. With the car turned off, doors and trunk closed, measure the current. Someone once posted what the "off' current drain should be (BrianK?), but something less than about 40 ma is reasonable. If the current is higher, then start removing fuses until you find the circuit with the high "off" current.

 

[shawn110975]

wow lots of threads being created recently from you guys up north. its cold NSX no likey the cold weather.

I know my post didnt help but the cold weather does some funny stuff.

 

[VancouverBCnsx]

Things seem to be getting more serious

Thanks for the input but the starting issue now has other developments. Yesterday when i attempted to start it on 2 occasions, it started momentarily and then died completely seconds later with no reading at all on the tachometer at the time of start up. On the second attempt afterwards , the only sound was the fuel pump clicking. It would not start subsequently.

Today I cranked the engine expecting nothing and it surprisingly started. However after driving it around the block and back into the garage, it unexpectedly shut off and would not restart. When it abruptly shut off, there seemed to be an unusual amount of gas fumes coming from the passenger side exhaust considering it was now warmed up (although it is just above the freezing mark temperature wise in Vancouver.

Jim Cross has graciously offerred to track down what appears like a parasitic draw when he is next in Vancouver. I am assuming that the 2 issues are connected and perhaps there is a faulty ignition switch or main relay or an engine issue.
From what I have described, does anyone have a more probable explanation of what is going on? Thanks

 

[Briank]

Start and die is a classic main relay bad issue.

 

[ftuhy]

^ +1 on the relay !

 

[nsxtasy]

Start and die is a classic main relay bad issue.

Based on that advice, and given the low cost of a new main relay (under $100 list) and how easy it is to replace (under 15 minutes and even an amateur can do it), I'd replace the main relay before going any further, and see if that cures it.

The part number for the main relay on a 1991 NSX is 39400-SL0-003. Remove the upholstered bolster at the top of the wall behind the seats by gently prying up from the bottom edge and you'll be looking right at it, in the middle of that area.

 

[JD Cross]

When I get over to Vancouver we'll check for parasitic drain with a multimeter.
I also just replaced my main and fuel injection relays as a preventative measure.
The two I removed are still good.
We'll put those in.

If that doesn't work we'll be back for more help

 

[J KRIB]

Where in Vancouver are you located? Might be able to help you out, the shop I am at is in Vancouver and I am located in Burnaby. PM if you need some help.

 

[VancouverBCnsx]

UPDATE
I purchased a new main relay and got it reinstalled........ (I must be a mechanical genius!)
Unfortunately this has not solved the issues. The car subsequently started and I let it warm up. However after turning it off and trying to restart it there was a pretty loud ticking noise coming from directly behind the driver's seat and the car would not restart.
Suggestions?

Fortunately JD Cross is dropping by in a couple of days so somebody with a lot more experience might be able to figure this out.

Marc

 

[Briank]

Click click no start most likely a bad connection on the battery or body end of the ground cable.

 

[Redgts]

The NSX draws more than power from the battery when off, than compared to most cars. Its weird.
I have starting issues myself earlier in the year, ended up replacing the battery, then the starter. Turns out it was the starter thr whole time.
When I replaced the battery I replaced the cables and connections too, I recommend you do that, and stay away from "gold plated" crap.

I trickle charger would be a good investment too, if your like me and only drive the car once a month.

AND...its not RELAYS, dont drive your self nuts replacing those.

- - - Updated - - -


The NSX draws more than power from the battery when off, than compared to most cars. Its weird.
I have starting issues myself earlier in the year, ended up replacing the battery, then the starter. Turns out it was the starter thr whole time.
When I replaced the battery I replaced the cables and connections too, I recommend you do that, and stay away from "gold plated" crap.

I trickle charger would be a good investment too, if your like me and only drive the car once a month.

AND...its not RELAYS, dont drive your self nuts replacing those.
I would bet $100 , you need a new starter with what you described in your last post.

 

[VancouverBCnsx]

The problem seems to be resolved thanks to the input from you guys and the detective and technician work performed by Jim Cross. After removing the ignition switch, cleaning it up and reinstalling it, the car seems to be starting up and running as if it was 22 years younger.
Thanks to all for their constructive input.