Hey I was driving my car today and I went to a friends house, when I left to go back home my car was having trouble staying started, it would start then die if it wasn't revved a bit. I let the car sit for a while and then tried to start it and it started fine but it seems like it's rpm's dropped while idling. Anyone have any idea what the problem could be?

 

that sounds similar to a 'hot soak' condition affecting 00 accord v6's. does the problem only happen during late fall to early spring when it's unusually warm outside?

 

Ummm, I'm not sure it's pretty cold but it was slightly warmer and it was driven pretty hard back down from Thanksgiving, could that cause the same problem?

 

no, the hot soak condition i'm referring to occurs only after you drive it till it's warmed up, then you shut off, then you go back to the car and start it up while the engine is still hot, and only when it's the winter season(or if a gas station is using winter blend fuel for some reason)

the weather is warmer but the gas stations already switched to the winter blend fuel(which has a lower fuel boiling point). the accord fuel pressure regulator has fuel pressure in the line too low(for winter blend fuel)which causes the fuel to boil in the rail - aka vapor lock.

starting the car with this mix of liquid and vapor fuel causes a very rough idle, excessive cranking to start it and possibly a misfire code. if you hold the rpm around 2000-3000 for 30 seconds or so(to clear the vapor) everything runs normally.

this problem, according to honda, only affects the 00 AV6.

is the weather below freezing now or when the problem happened? a rough idle can be from moisture freezing in the map sensor also. but it would only causea problem on a cold start only.

a going bad fuel main relay can also present similar symptoms. typicially it fails after you drive and the heat is on(or if it's summer and already hot in the car) and you get a no start all the time. tapping on the main relay will then start the car up usually.
if the contact in the relay is starting to go bad it can cause a bad connection causing starting problems. but typically once it's started it should be fine.

the engine is rock solid in my opinion, so driving it hard is what it was meant to do!

 

Alright well I'll try holding the rpm's then. Will that help with the rough idle?

 

well, i'm not sure how your idle is acting. if it's starting then dying, then when you eventually get it started the idle is messed up and you rev it up to keep it running like you said...then in this case increasing the engine rpm for 30-60 seconds is a test.
it should clear any fuel vapor in the lines by doing that. if the idle is still messed up you know it's not a fuel vapor problem. also note the engine has to be hot for this to happen in the first place:


if it happens only when the engine is cold, i'd lean toward something likefrozen moisture in the map sensor or some other more concrete problem.

if it happens all the time no matter what i'd suspect something like low fuel pressure, egr stuck open, (depending on the idle problem - low coolant), etc



can you duplicate the problem? happens when the engine is hot? cold? after short drives? all the time?
can you describe how the idle is acting?

 

My 2000 accord v6 only does this when it is hot summer time. ?????