2000 Honda Odyssey Won't start in cold weather

Thanks I will try anything, would a bad main relay make it difficult to start in cold weather? It just cranks and cranks you could try it 15-20 times and won't turn over, I keep going out every hour or so and try and it does the same thing usually about afternoon time I go out to try put the key in and turn it and it starts first time, then of course it has white smoke come out and smells like gas then once it's running for 10 mins or so it's fine, I could drive it down the road turn it off let it sit for a minute then turn it on and it starts right up, it's just that initial first start in the morning once I get it started it's fine all day. I'll take any ideas and appreciate you taking the time out and getting back to me I will try the main relay. I love this van and want to keep it I have four children and it's such an inconvience all winter long when it does this. I forgot to mention that one mechanic tried unplugging the crank sensor and it starts, then he lets it warm up plugs the sensor back in and starts it and it starts up thats the only way we can get it started when it has this problem other than wait until it gets warmer and it starts on it's own. Thanks again

Ok Thanks for your help, we did have it to two mechanics the first had it for almost a month this winter and the other had it for two months this winter, when they try starting it they found there was no spark, we also try spraying it with the starter and it didn't work we do find it odd that when the crank sensor is unplugged it will start, thats why one mechanic said to replace the computer which we did and that wasn't the problem, also had it to Honda which said 4 out of 6 fuel injectors needed replacing, my husband said no way I wouldn't be able to drive down the road if that were the case so I left there and that was three years ago. Well I appreciate it I will replace the main relay I'll give anything a shot.

Our van starts each and every time when we unplug the crank sensor, putting the computer into back-up mode. Would a faulty relay somehow be affected when the computer is in back-up mode since it doesnt come into play while in the back-up mode. Im sure unplugging just about any sensor would most likely put it into back-up mode but we've had luck in the cold by unplugging the crank sensor.
The computer has been replaced, but we still have the same issue (same with almost every sensor being replaced).
The problem is usually always hard starting once it starts getting cold. Since we've gotten to warm weather we seem to be good, just as it is every year.
We've had previous check engine light reading bank 2 oxygen sensor, which has been replaced twice. Now we have rec'd the light and it reads catalytic convertor efficiency.
Any of this make sense to you? Lol

I have A 2001 Odyssey that is doing the EXACT same thing (weather not being an issue). Let it sit for a few hours or overnight & it will not start. Check Engine light & TCS light will come on at the exact same time. Unplug Crank Senor & it will start & run rough & PO335 code will come up. Shut the car off, clear the code, plug in the sensor and it will start & run perfect for hours & miles, check engine & TCS light will stay off until it sits for a few hours then it won't run again unless you do the exact same thing. Replaced crank sensor with no results.

Thanks. Tore vehicle back down to check crank sensor; sprocket & recheck timing marks. Timing belt had jump or a timing mark was off a notch, was off one tooth so cam & crank sensors were out of sync.

I have the same exact problem with my 2000 Honda Mini van. The problem started at 120k miles. It now has 135k miles. I've changed every sensor, the relay. I was ready to do the injectors but at this point I feel like my mechanic is guessing. My solution is I leave the van in the garage during the cold (37 degrees or below)temps. My prob is when I go to start in in the cold weather, it turns over, turns on (for a sec) turns off, kicks back, like its out of timing. Its the strangest thing. I found that I can duplicate the problem in the 40 degree temps. I start it, run it for 8 secs, then turn it off, then when I try to start it again, it gives me the same prob as it does in the cold starts. I DONT KNOW WHAT TO DO! PLEASE HELP!

I think I corrected the problem. Try changing the Map sensor. My car wouldnt start this morning at 34 degree temp. I immediately changed the map sensor and the car started right up. See bulletin below.
04-004

Applies To:
1998-02 Accord V6 - ALL
1996-00 Civic DX, LX - ALL
1999-00 Odyssey - ALL

Rough Idle at Cold Start; MIL Comes On With DTC P0107 or P0108
(Supersedes 04-004, dated March 5, 2004)

Updated information is shown by asterisks and black bars.

Failed Part: P/N 37830-PAA-500
H/C 5430319

Defect Code: 03214

Symptom Code: 09103

Skill Level: Repair Technician

SYMPTOM

In cold weather, the engine idles roughly after a cold start. The MIL may also come on with DTC P0107 (MAP sensor circuit low voltage) or DTC P0108 (MAP sensor circuit high voltage) set.

PROBABLE CAUSE

Moisture freezes inside the MAP sensor.

CORRECTIVE ACTION

Replace the MAP sensor. For Japan-built Civics, also replace the intake manifold.

L am Still having the same prob. The new MAP sensor seems to make it easier to start during cold temps (when I step on accelerator during the cranking) but I still have the problem. Van has been with a mechanic now for 2 weeks. He asked me to leave it with him after the crank position sensor code came on 2 times in one week. He's going to tear the car down again to replace the crank position sensor again. Im thinking mabey its an after market issue in the after market part versus a honda factory part. So now, I'm getting a CPS directly from Honda (I bought a bottle of vaseline - lol). Here we go again. Im also replacing the IAC valve while the car is apart to see if that hepls.

Van now has 141k miles. Runs perfect but for the cold starts prob (doesn't burn or leak anything). What an F-n shame.

I will let you know what happens. Any suggestions would be great. C Galarza 516-797-1600