moda_way

So I'm looking for things to check out b/c I had a very strange experience yesterday afternoon getting ready to leave... let me explain.

Car: 2004 TSX 6MT, highly modded, 84k miles
Prior to Incident:
Arrived at work at 6am, shut car down.
Started car at 7:30am to run to a meeting across town, everything fine.
Reached meeting, shut car down.
Left meeting, started car, everything fine.
Park car back in normal lot until end of work day.

The Event:
Popped Trunk to put laptop in and closed. No issues
Unlocked car and open door.
Insert key into ignition, step on clutch pedal, rotate key to start.
[Start Stopwatch]
Radio turns on and push key to starting position and everything flickers then no power.
Notice water temp light pulsing (like an over heat situation)
Rotate key back and scratch head.
[Stop Stopwatch - elapsed time, 5 seconds]
Unplug radar detector.
[Start Stopwatch]
Rotate key forward to Acc and Stage I
Radio operational, all HVAC functions, lights, etc functional
Notice no recognition of the Immobilizer key on display
Rotate Key to Start position.
Gauge lights and others flicker as before.
Noticed this time that starter sounded like it was shorting out or attempting to jump to start and had a poor ground.
[Stop Stopwatch - elapsed time 30 seconds]
Rotate key out of ignition.
Opened hood and verified all connections were solid at the Optima, including a new ground that I put in last summer. All were solid. Looked at the alternator and start motor to verify plugs were in good condition. Re-verified that battery connections were good. Left the hood open.
Jump back into car.
Stomped on clutch pedal again, turned all accessories off.
Rotated key back to start and a millisecond flicker and the car starts.

So I head back to the engine bay and listen. Nothing unusual at all, no hesitations, RPM at idle is fine, no electronic burn smell.
Close the hood and begin testing accessories. All back to normal operation, no loss of radio memory, no components (Sirius or Passport) having any issues. Even look at the Passport, set to show volts, and all is well.

I have to run to the store to pick up a few groceries. On the drive, I'm testing motor functions (still pulling like normal) all is well. Pull into parking lot, shut the car down. Pause. Attempt to restart... all is well.

So this morning, I get into the car and all is fine again. So.... WTF do you all think it could be? This is a singular incident and has never been seen before on my car.

nbtx

dying battery - pull it and get it load tested by a shop with a decent battery analyzer. My AdvanceAuto store has one, or maybe AutoZone or NAPA.

vthree

iTrader: (1)

odd... =X i was gonna mention switching the radar to voltage mode.. but you already knew that!

moda_way

Could do a load test I suppose, however, no issues have been present (e.g. tough starts, slow starts, etc.) Also, given my lightweight flywheel, it takes nearly nothing to get this thing pumping.

I keep it in voltage mode all the time.


My only theories right now is a loose ground at the battery, a bad clutch pedal sensor/switch. However, neither of these takes into account the immobilizer ring not showing me the flashing green "accept" for my key on my second attempt to start yesterday afternoon. It also doesn't explain a flashing coolant temp light. Those could be symptomatic of the ground issue... maybe, but it was rather random. The only issue that closely relates to it is if you blow the backup main fuse (which I did on my wife's 01 Civic EX), when you go to turn on the car, the gauges go nuts and it will turn the car over. My fuse isn't blown, but it reacted the same.

LukeaTron

I was thinking the clutch switch too. If it's jumping back and forth from on to off rapidly it might be confusing the ECU and causing the funny things you're seeing. The logic of the ECU may not be able to handle the state of that switch changing so rapidly and thus be causing the ECU to end up in a state the engineers didn't account for.

It's going to be hard to diagnose unless it happens again.

moda_way

Agreed. It was hard to be systematic about it when you are pulling your heart out of your stomach.

moda_way

Figured out the issue today. Repeated same issue as stated before, but now I had the time to look into it further.

And the winner is..... poor ground. I installed an aftermarket ground block and it wasn't grounded well. I put the stock one back on and its all better now.

curls

Damn I was gonna say bad groud too but you figured it out. I clean my battery terminals and ground points every spring and fall because of corrosion. I find little gremlins creep in throughout the year until I clean the grounds, and then everything is back to being just fine.

Basically, anything electrical going wonky means you should check the grounds first, then everything else second.

Glad to hear it's fixed though moda...

curls

I forgot to mention, I had a strange problem when my ground was giong flaky last time. one in every 10 starts, I would get a strange and often startling BUZZZZZZ from the steering column when turning the key over. I haven't figured out what it was, but I'd just turn the key back to OFF and then crank it over again and all would be fine. Cleaning/tightening the grounds eliminated this problem too.

moda_way

Funny you mention the buzz. I just figured it was a relay going nuts or something, but since you said it, I remember the same thing from mine. Luckily, the car is back to 100% normal (if you can call it that given my mods).

One other side effect of this is in conjunction with the volt meter in my Passport 8500. On the drive in this morning, with the OEM ground back on, I notice my volts being much more stable, around 14.2-14.3v consistently. So my ground has been weak for a while, but it worked okay enough to run the car. Hopefully my Optima hasn't suffered too much.

curls

This should be in the dictionary as the example of an oxymoron.

I did have my battery changed last fall and since then I haven't had the buzz, but then again I clean the grounds enough that it shouldn't come back, ever, as long as I stay on top of it.

The buzz sure is startling the first time you hear it, isn't it?!

moda_way

Yeah, you'd think a quality ground block would work, but I guess it was the installer's fault.

intensity2x

I know you already fixed this problem, but I figured I'd give you a possible explanation for this aspect. The red overheat light also doubles as the factory alarm light. The drop in power could have turned the alarm back on, I've had this happen with other cars with dying batteries. This would cause the light to flash.

moda_way

^^Nice follow-up and good point. I hadn't thought of that, but that probably does explain why that light did flash red. Interestingly enough, it almost acted as if it was tossing a code because it flash, if I recall that particular incident, a handful of times and then stopped.

Miamicarfan

hey guys,

Where is this "ground block" on the TSX located? I want to look at it and check if it has corrossion. Do I just follow the negative battery post cable to the bottom of the car?

moda_way

Follow the negative cable. It is a few inches away from the negative terminal.

Miamicarfan

Moda:

So you can do it from the top? is not easier to jack up car and do it from bottom?

Thanks.