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Hi,

My 99 V8 has been off the road for some time through no fault of its own however now I am using it I have noticed a problem...maybe!

The idle speed is about 1100 revs ,raising to 1500 when I was stuck in hot traffic jam on the m25 the other day.Is this normal??

I know I may have a problem with one of the pre cat o2 sensors and the chap who came our to recover my Range Rover (again) today reckoned the MAP sensor on top of the esprit engine was falling apart ! Whether this would make a difference I dont know.The only fault code to appear is one for the o2 sensor.

The battery has been disconnected but the idle problem occurred after 100 miles of normal driving after this.The A/C was recharged last week and the engine left running afterwards to relearn the ifdle speed with the A/C on .

Any ideas?

Rich

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Thanks Jay,

For the last couple of days its been more steady but it is always 1100 or more.I,d be interested to know what the factory norm is for the V8 engine.

I know I have a bad 02 sensor which is being changed on Friday.Apparently my map sensor is also faulty which may cause a high tickover.

I ,ll have to see.

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My 98V8's handbook reads:

"V8 Models: Engine idle speed is controlled electronically by the engine management computer, and is normally about 850 rpm, although on initial return to idle, an engine speed of 1100 rpm will be maintained for 20 seconds before slowly decaying to 850 rpm. If the idle is disturbed by throttle pedal movement, the raised idle and decay sequence will be re-applied.

An uprated idle speed is required under certain operating conditions including when the a.c. is operating, and during the engine warm up phase, when the raised idle helps to speed the time taken for the catalytic converter to reach operating temperature, as well as to aid rapid demisting, and inhibit stalling. Idle speed will return to normal automatically when the engine has warmed sufficiently.

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Mines seems to always start between 1-2k rpm and slow down.. and it does it even when the engine is warm.. I was told this is normal.. the car operates perfectly besides that also.. Probably just the way it is? the weather has been colder here lately also..

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Thanks for everybodys responses.

It sounds like mine is normal .I picked up the new o2 sensor today which should cure the slight lumpiness and I,ll assume 1000 to 1500+ is normal from now on.

Richard

sport350

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My 98V8's handbook reads:

"V8 Models: Engine idle speed is controlled electronically by the engine management computer, and is normally about 850 rpm, although on initial return to idle, an engine speed of 1100 rpm will be maintained for 20 seconds before slowly decaying to 850 rpm. If the idle is disturbed by throttle pedal movement, the raised idle and decay sequence will be re-applied.

An uprated idle speed is required under certain operating conditions including when the a.c. is operating, and during the engine warm up phase, when the raised idle helps to speed the time taken for the catalytic converter to reach operating temperature, as well as to aid rapid demisting, and inhibit stalling. Idle speed will return to normal automatically when the engine has warmed sufficiently.

Mine also as above....... but never drops to 850 stays at 950 +

Mike

Edited by MKE40

"Neglect not thy opportunities"

Martock ,Somerset. 1661

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Thanks Mike,

Its just had its first 'HARD' run today ,without cats and with new oxygen sensor and well its fast!

The tickover still stays at about 1300- 1500 and then slowly drops to about 950-1000after a few seconds.This all sounds relatively normal.

What is more worrying is that the clutch feels like its slipping.It may just be that in 9 months it hasnt done much or that something is wrong .Either that or the wheels could be spinning in the first 3 gears on 3/4 to full throttle.Its only done 24k so I hope its the latter.

Thanks for everybodies input on the tickover issue.

Richard

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Thanks Mike,

Its just had its first 'HARD' run today ,without cats and with new oxygen sensor and well its fast!

The tickover still stays at about 1300- 1500 and then slowly drops to about 950-1000after a few seconds.This all sounds relatively normal.

What is more worrying is that the clutch feels like its slipping.It may just be that in 9 months it hasnt done much or that something is wrong .Either that or the wheels could be spinning in the first 3 gears on 3/4 to full throttle.Its only done 24k so I hope its the latter.

Thanks for everybodies input on the tickover issue.

Richard

I dont like building the revs and dropping the clutch in any car let alone the V8.

However once rolling the other day I floored the throttle changing quickly to second and the tyres lit up through sheer torque in second. so could have been that same scenario in your car?

Mike

"Neglect not thy opportunities"

Martock ,Somerset. 1661

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