engine idle dips below normal after slowing suddenly

[col_b]

Hello,

I have a 2001 Nissan Primera Sport and have 2 problems:

1) After driving at normal speed (~ 30/40 mph) and I slow and stop suddenly, the engine revs dip below normal to ~ 500 rpm. They will then return to normal (~ 750 rpm). What could be causing this? The engine doesnt stall; the engine recovers to its normal idling speed before it stalls.

2) Sometimes, the car is slow to turn over when the engine is warm. The car starts great when it is cold, and it idles fine when cold too. But when I start the engine when it is warm, it is very slow to turn over and then it will start. (The car always starts; it is just slow to turn over...). Does the car need a new battery? (Lights / wipers etc. work fine though).

Are the two problems related?

Cheers,

Col

[Mr Whippy]

My car was doing the same sort of thing recently.

Put a new battery on, after 45 mins of radio on while washing the car it flattened it, so that was the final sign that pointed out my battery was shot.

I had it stalling as I dipped the clutch when setting off in cold late at night (full beam, heaters, rear screen elements, radio etc) alot of drain after a start and the engine just stalled probably due to high load on the alternator?

How old is the current one on it?

Dave

[annodomini2]

If its the battery, use an automotive mutilmeter across the terminals (when engine not running) should read about 12.5v when ok and fully charged. Significantly less if a cell is dead.

If its ok, check the voltage with the engine running, should read approx. 13-14v if not then it's probably the alternator, if its spiking then the regulator on the alternators gone.

[col_b]

Thanks for the advice guys.

I reckon the battery is the original, which means it's over 4 years old, which means it needs replacing. But then she starts strong when cold...

I'll get hold of a multimeter and see what it says.

Anyone know the cost of replacing the regulator on the altenator if it turns out the battery is fine???

Cheers again,

Col

[Pigeon]

My guesses would be:

1) Throttle stop switch dirty/not working properly - try a squirt of contact cleaner (NOT WD40!!!)

2) Not the battery because it only does it sometimes. Probably the starter motor - and probably nothing to worry about; my mate had a Nissan pickup that was like that all the time; it always sounded like it wasn't turning over anything like fast enough to start but it always did.