Idle test failure

The Govt set the limits.

All the testers' manual says is

"1. The engine a. is idling at a speed clearly above its normal idling speed"

I don't think that would fail at my tester, I will ask on Monday. The idle speed is adjustable on one of those according to autodata!! it looks like it is an electronic adjustment and I don't know how it is done.

Mrcheerful

Ford

Unless your tester is stupid it would. the only reason to bypass the speed measurement is if you cant connect to it. Older EGA's connect to a plug lead and you could bypass some coilpack type's and use the rev counter, modern EGA's just connect to the battery and there is no legal way to bypass. I don't even know if our machine would let you do a test without the speed measurement? To get a reading of 877 means that the speed can be measured.

"Fred"

all EGA's have to have the facility to bypass the rpm if needed, as you rightly say the rpm is picked from the battery connections, as ours does, but if you have a vehicle that you cannot access the battery, for instance some bmw's have the battery under the rear seat & as dismantling isnt allowed during an mot test, you have the option to bypass the rpm from the battery and use the vehicles own rev counter.

with regards the OP, the gas machine counts down from 30 seconds to zero, but i have noticed on certain vehicles that the countdown gets to zero before the idle speed has "calmed down" from fast idle.

For the past two MoT's I've used a different MoT station and noticed on both times the emission print out says "engine speed measurement was bypassed". I've no idea why, it's only a Daewoo Lanos so the battery and ht leads are easily accessible!

too lazy to hook the two leads up to the battery, takes a lot of effort you know ;o)

My Mot man said that it would NOT be a failure at such a low speed. So ask for a VT17 if that was the only failure point.

Mrcheerful