Engine question: idle engine

[anicorsa]

Im not very mechanically minded when it comes to cars, so i have a question.

How many revs should your car be at idle?


Reason why i ask is because my car used to idle at around the 1000-1100rev mark, not it sits around the 600-700 mark and has a bit more trouble starting than it used too... :shock:

WHats going on??

[Vectracious]

Cars usually idle anywhere between 600-800rpm usually. Idling around the 1000-1100 mark (unless the engine is cold) is unusual.

Sometimes the idle speed is found on the Emissions plate on cars or in the specs part of the manual.

[anicorsa]

I had a look at the emissions plate.. it said 820 +- 110, so its about right. Probably more on the lower end of that figure.

Then why would the car struggle to start? could it be the spark plug? i dunno..

[Vectracious]

IS your battery OK?

Spark plugs clean?

Cars tend to take longer to start as they get older - I know yours is only 2 years old, but my Vectra now takes longer to start than it did brand new, especially during winter.

[anicorsa]

hmm, could be the spark plugs, i'll have to have a look.

Battery, i did just get a sub, and had been pumping it pretty loud with the engine on. COuld it be that the batt cant handle the power load?

The problem is only minor, i was just curious to know why a car would take longer to start. It wasnt a cold engine either.

[Rhino]

When you turn your key to the 'on' position, wait a while for the fuel pump to work (you'll hear it start and stop after a few seconds), then try starting it and see if it is any different.

[anicorsa]

Ah, so its just the lag time for the pump to pump the fuel?

[Rhino]

Possible, just another thing to try.

[anicorsa]

ok, cool.. i'll try that when the engines cold, as thats when its longest to start.

[Vectracious]

The sub/battery thing might be an issue. Maybe someone with a system in their car can shed more light.

The "wait for the fuel pump to stop pumping" issue is an interesting one. SOme people say turn the ignition on, you;ll hear a slight buzzing noise that stops in anywhere between 1-5 seconds (depending on the car) and only when it stops you start the engine.

I have asked many many people in the know (mechanics/service managers/people that know) and the majority of people say that it doesn't make a difference. You won't wreck you're fuel pump, and the car isn't going to start any easier.

Now in saying that, I always wait for my fuel light to go out (goes out when the pump stops buzzing) before I start the engine in most cases, and sometimes when I don't, the engine does take a little longer to start - but it could also be my imagination.

As Rhino said - it's worth trying. :)

[anicorsa]

Yeah i just tried it then, didnt make a difference.

Like i said, it was only slightly longer than when the car was new. I was just wondering what contributes to it.

[Lopel]

also i would have your spark plug leads checked, i think in the post somewhere someone said your car is only two years old, you never know, it could be possible that a lead might be breaking down and not firing properley, ive had the same problem with mine recently with a rough idle and performance wise..had a quote to replace sparky leads and was looking at the $400 dollar mark.. so you might wanna have it checked to be on the safe side..

Regards
Lopel

[frankie9fingers]

XC barinas don't have leads, they're coil overs.

Notice since winter began, the troubles rise up? I've got gear selection when cold, and a faint electric cutout when i first takeoff in the cold.

[anicorsa]

Not really, sometimes i get the gear problem, cant get it into reverse.

But since winter began it just takes a little longer to start. I'll keep an eye on it though.