escort mk5 fast idle mot failure

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Wed 25 Jan 2006 11:20
escort mk5 fast idle mot failure - 1066elsey
a friend of mine had his ford escort 1.6 96 fail the mot . Mot tester said failed fast idle test. Any ideas as to why it wouldnt stay at fast idle .I belive it dropped revs Any ideas would be a great help .

simon
Reply | Report as offensive | Link
Wed 25 Jan 2006 14:38
escort mk5 fast idle mot failure - jc
The tester holds the speed on the throttle(usually 2750rpm +250/-250)and measures the emissions.
Reply | Report as offensive | Link
Wed 25 Jan 2006 21:22
escort mk5 fast idle mot failure - Andrew Moorey (Tune-Up)
Need more info really. If, when the tester raises the idle speed for the fast idle test the revs wont hold steady, could be a lazy Lambda (HEGO/O2) sensor going excessively 'lean' then 'rich'. Need to check output via an oscilloscope or graphing multimeter. What sort of mileage has she done?
Andrew
--
Simplicate and add lightness!!
Reply | Report as offensive | Link
Wed 25 Jan 2006 22:14
escort mk5 fast idle mot failure - bell boy
as Andrew Moorey says most likely the lambda not switching common on escorts and i never understand why mot stations don"t at least give customers pointers to fixing the situation as their machine tells them whether the lambda is working or not,its as if they are frightened of the scenario "but you said it was that" whereas most people would like an idea of the problem rather than being told by dave down the pub "its your ecu mate".
as a matter of interest i think that overfuelling on escorts/fiesta"s on the initial start kills the lambda on these old fords.
Reply | Report as offensive | Link
Thu 26 Jan 2006 16:39
escort mk5 fast idle mot failure - 1066elsey
Thanks , basically tester cannot run the thing at fast idle long enough to test , revs will not hold for required time..mileage is about 120,000 .Tester wasnt great , My own tester does point me in right direction ,(normally tells me wants wrong and how to put right ) but me mates tester seemed to be it failed here the list Bye bye

cheers all

Simon
Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide