Occasional failed start

[Towncivilian]

I have about 121.5k miles on my 2001.5 R50 2WD A/T. Once in a while, I'll try to start the car and the vehicle cranks a few times but doesn't start - I stop trying to start and wait a few seconds, try again and it starts up immediately. Battery is several months old. Doesn't matter whether it's warm or cold. I always turn the key to the "ON" position before starting the vehicle to prime the fuel pump and have sensors, etc. powered. There is no additional electrical load (headlights are off, A/C not running, head unit is usually on though) when I start the car. Spark plugs replaced less than 500 miles ago with OEM NGK, fuel filter back in May. Any ideas? Early signs of a failing starter?

[fueler]

does the starter slow down & sound weak when it does this? or is it cranking fine and the engine isnt starting?

gut instinct tells me starter or batt... dont factor a bad battery out just cause its a few months old... could have a dead cell.

[Towncivilian]

It does sound a bit slow, but I'm not sure. I will listen closely next time this happens. I wish I could record it but with such a random nature, unless I bother to record every start, that's not gonna happen.

[Densetsu]

Does the red security light to the left of the steering wheel light up? Mine does this from time to time -- turns over normally, but the engine won't fire, and the security light comes on solid (it also leaves a code in the ECM, P1614, but won't turn on the check engine light). I take out the key, put it back in a few seconds later, and it starts up fine. The code will stay around for quite a while.

The ignition keys for the R50's use an RFID chip to identify itself to the ECM. If you have other RFID fobs on your keychain, the NVIS system may read those codes instead of the key's code. Gas station "quick pay" devices (e.g. Esso/Exxon/Mobil Speedpass) often use these, and are pretty common. You might also have a fob to give you access to a building. I've moved my fobs to the opposite end of my keychain to try and minimize the interference, and so far so good.

[Towncivilian]

I will check the security light next time it fails to start. Though after a failed start, I don't reinsert the key as you do, and it starts up just fine on the next attempt. I will also pull the codes using my USB OBD2 scanner next time I have access to a laptop.

I carry both of the keys to my PF in my left pocket (both have cracked or nonexistent plastic rings where it'd go on a keychain, so I keep them in my pocket to avoid loss), which only houses my wallet, flash drives and sometimes a pack of gum. I don't think any of the cards in my wallet have any RFID stamps inside. I do not always use the same key each time I start the vehicle, it's just whichever one I pull out first, so perhaps that variance causes the issue. Though since I give the system some time in the "ON" position, I'd think it'd catch up by then...

[oasisx]

sounds similar to a problem i have. Next time it happens keep the key turned and see if it eventually turns over. Mine does the same thing as you stated and if i keep the key turned it eventually starts after 5 seconds or so. it only happens occasionally but Its hella annoying tho when it does happen

[Towncivilian]

sounds similar to a problem i have. Next time it happens keep the key turned and see if it eventually turns over. Mine does the same thing as you stated and if i keep the key turned it eventually starts after 5 seconds or so. it only happens occasionally but Its hella annoying tho when it does happen

I will try that too. No failed starts as of yet since the topic post date.

[Towncivilian]

Happened tonight. No security light lit. It sounded like the starter was stuttering and it didn't start within a few cranks, so I stopped trying and tried again in 2 seconds and it started with no problem.

[Towncivilian]

Happened once last night; starter just stuttered and wouldn't start after a few cranks, I let go and it started fine on the second attempt. This was after filling up when everything was hot and the same key was in the ignition the entire time. The ignition was in "ACC" while filling up, then "ON" for 10 seconds to prime fuel pump etc, then attempted to start. Any clues? Shall I test battery voltage at off/starting/on to begin with?

[qx4girl]

Sounds like your starter contacts are going out. I had this problem on my old car. Took the starter in to get it tested, and half of my contacts were bad. Replaced it and had no issue since.

[ARKQX33V6]

1 test that battery, after a full charge needs to be at 12.6 VDC
Then try a cold start, you could depress the gas peddle 1/3 way, or not but with a helper reading a meter on Volts DC 20 V range start the engine and the helper reads the meter to determine lowest voltage while attempting a start.
If it start let warm up then take a voltage reading at 2500RPM.

Voltages should read
12.6 after a full charge.
No less than 10 VDC while starting.
14.6 up to 15 V max at 2500.

If readings are around these numbers battery is good.

With a good known battery you will need an amp meter or clamp on to go around the positive lead wire. With a helper start the vehicle read the max of amps the starter draws.

Should be about 180 A but the range could be 224-350 A. The amps will peak fast and diminish as the starter turns.

The ampacity may vary especially if cables, connections, contacts are loose, worn or dirty.

But the first thing that comes to mind could be your fuel pressure or pump lagging behind. A fuel pressure gauge at 50 PSIG is needed plugged into your fuel rail. Good luck!

[Towncivilian]

I cleaned the battery posts and terminals with a wire brush about a month ago, and I've not had a failed start since. Of course, it's also getting warmer, but I'd expect a battery to tolerate the >40F winter conditions of southern Florida without an issue. I suppose I'll see this upcoming winter whether cold is truly a factor. I haven't tested my battery, but if I do get another failed start I'll probably do so.

[donald]

...
I carry both of the keys to my PF in my left pocket (both have cracked or nonexistent plastic rings where it'd go on a keychain, so I keep them in my pocket to avoid loss)...

i know this is OT from your intended discussion, but since you mentioned it and I came across these threads tonight:

broken key-eye: zip-tie fix: post5212616.html#p5212616
there's even discussion in this thread about drilling a hole away from the RFID chip

broken key-fob-eye: quick-and-easy-fix-for-busted-remote-t529506.html

[asnorton44]

On my 01 sometimes it will crank really slow twice, then start. Hmm.

[ARKQX33V6]

asnorton44, eliminate possible battery problems, then 1 by 1 check the easy stuff:
Battery
Cables
Connections
Start relay
Starter
Timing
Fuel supply
ignition

Try to eliminate 1 thing at a time.

How are your spark plugs?
Air filter
Gas filter

Easy things first.