discovery td5 idle speed error

discovery td5 plugged to nano com ive got a fault idle speed error any one know what it is and the cause your help will be a help

Hi Ultra,

Don't panic it's not an error at all. The figure given is calculated by Nanocom unit and is the difference between actual engine speed and what the idle speed should be.

Normal idle speed is 742 rpm give or take a smidgen so if actual engine speed is say 2500 the idle speed error will be showing 1758 if my maths are correct.

Now don't ask me what use this is because I haven't come up with one yet but if anyone can enlighten me/us I would appreciate it.

Regards

ok thanks its just i thought it was a cause of a problem i have which is when reved and let to drop back to normall idle speed it holds just above normal idle and theres a knock presant ??? ive had it checked by loadsa people and no one has a clue engine is in great cond no wear any where had it all checked out its been serviced new head gasket as it was thought this may have been the prob but no differant injectors have also had new seals and washers to the clutch is due to be done along with flywheel and spigot bush as its noisey its had new fuel pump also when head was off changed fuel reg filter and gasket.. im stumped in what the cause is no one knows i need help !!!!!

borntobemild said:

Hi Ultra,

Don't panic it's not an error at all. The figure given is calculated by Nanocom unit and is the difference between actual engine speed and what the idle speed should be.

Normal idle speed is 742 rpm give or take a smidgen so if actual engine speed is say 2500 the idle speed error will be showing 1758 if my maths are correct.

Now don't ask me what use this is because I haven't come up with one yet but if anyone can enlighten me/us I would appreciate it.

Regards

Click to expand...

what you are describing is the 'idle speed deviation'

hello ratty long time ! what do you mean by that and causes

ultra150 said:

hello ratty long time ! what do you mean by that and causes

Click to expand...

The idle speed deviation is the difference between what the tickover speed should be and what the engine speed is at that moment in time.

If for example your engine speed should be 750rpm on tickover and it was actually ticking over at 782 rpm it would have a deviation of 32rpm.

If you were flooring it and the revs were at 2750 then the deviation would be 2000rpm.

If you believe your engine is running high or low at tickover the deviation should be shown on the nanocom. If the deviation is just a few revs out then don't panic, It's normal. If it's more than a few rpm (10-15rpm ish) out then you MAY have a problem.

From what your saying with the revs taking a bit longer to settle I would try cleaning the MAP and MAF sensors.

yes ok but whats the knock and why does it only knock at that point no other knock what so eva through rev range or on the fall untill this happens when it holds its revs slightly and knocks it will also knock at free wheel when u park on a hill and its idling you free wheel and the revs raise slightly and the knock is there and when you stop it drops to normal and knock goes and its not anything else its from the engine .. its like a juggling knock