Afm

[philta]

i thought the engine wouldnt start without the afm plugged in? is their something wrong with my car, sorry for knobby question.

had intercoller pipes off, no afm, just throttle body sucking in N/A.

thanks in advance

[handyandy]

yeah, it may idle. But it wont idle well and won't be drivable.

[assyrian4evaa]

yeh i've found this out too (the hard way)

i was changing my filters over and i forgot to plug the afm back on started the car n it was ideling like shit i thot oh my god wat did i do??? i didnt think it wud be the afm not for 1sec coz i thot the car wudnt start but yeh i looked around and found that the afm wasnt plugged in i got so relieved wen it started idelling good.. phheww

Edited October 25, 2006 by assyrian4evaa

[lingeringsoul]

funny enough, I had the AFM unplugged before due to my paranoia after it was stolen once, I thought unplugging it would cause the car to idle like shit and deter opportunistic thieves. Well, one day, after starti9ng the car, I realised I hadn't actually plugged it in and it was idling quite well unlike the previous time where it wouldn't even idle....so that was a bit of mystry

[philta]

mine idle pretty dam well, HOW the FU*K would the car know how much fuel/air to mix if i cant calculate the air flow without the AFM, i just reversed it back onto the drive way because i need to move a car out.

*strange*

[Sumo]

HOW the FU*K would the car know how much fuel/air to mix if i cant calculate the air flow without the AFM

The car would look at its other inputs... e.g. Coolant Temp, RPM and put in a pre-calculated amount of fuel. The Fuel map in the ECU would tell it the values - and since your off boost, it should be able to get away with it a bit.

Cars do have to have a bit of tolerence if they lose a sensor, they may not run right - but they should be able to let you slowly drive home.

Cheers

Sumo

[philta]

yeah i kinda relise it would have to run on the o2 sensor since i had the throttle body bare. im quite surprise it idle so well., everything is back on and running fine now.

[Abo Bob]

Mine started and idled perfectly when I forgot to plug it back in one time. It wouldn't rev properly at all though.

[race_snooze]

same started and idled perfectly, just when you go to put your foot down nothing rev cough rev cough.

[StockyMcStock]

i had a Q45 AFM explode on me (long story) and i couldn't start the car. after picking up the pieces of the AFM casing i had to get a tow home was hoping i could limp it back but no go.

[Sumo]

yeah i kinda relise it would have to run on the o2 sensor

No, The O2 sensor only "trims" the mixture by a small percentage - It does not have full control over the mixtures.

Cheers

Sumo

[CEF11E]

on cold start at closed loop sections of the fuel map the car will run with out an AFM untill 1350 rpm on an RB20 as soon as cold start cuts out it will not run at all.

[MBS206]

They have 2 back up sensors to help correct bits and pieces.

MAP and TPS.