hi there i have a problem with my M reg jdm spec scooby its a ej20....

it has poor idling problems even when the engine is cold and hot it also cuts out while im driving and when i stop at the lights it just cuts out then i have to start it again and it idles poor... some times it idles ok but when i drive an stop it cuts out agen... could it be the air flow meter or idle valve control? can some one please help

Thank You
Mahir

 

most likely suspects are: MAF and O2 sensor

disconnect the MAF and see if it idles worse (it should)
disconenct the Lambda (from the headers just before the uppipe) and same thing - it should idle worse...if it doesnt in either case, then THATS the problem


good luck

 

i have disconnected the maf sensor and the car idles worse then it just cuts out agen... theres another sensor on the throttle body when i removed that the car just started idling higher..

 

sounds like the MAF MAY be OK
check the lambda (not sure wot the other sensor is that youve disconnected)

 

alright mate il give that a try and post back.. Thank you very much ian...
if any one else has any ideas please let me know

Thanks

 

the sensor on the throttle body is the throttle positon sensor

 

Sound like ive got the same problem mate, im driving an sti 3, im going to clean out the idle control valve tomorrow and check the MAF is working, if no luck there im heading for the spark plugs......... il keep you posted on how i get on. let us no if you have any luck your end.

 

i will do mate.. even when the turbo kicks in on 2nd gear it cuts out all the power and then when you let go and step on it agen it goes back to normal..
the check engine light is not on and when i put it on diagnostics it doesnt bring anything up..

 

by the way george i changed the spark plugs today and fitted ngk's and the problem is still there...

 

had the same greif car would not run with maf unplugged swapped it anyway now runinng perfect

 

i had/have the same problem with my wrx and turned out to be the coils. i stupidly bought some second hand ones though so the problem is still there.
going to buy some brandnew ones next week.

if you an try get some off of a working car to see if it fixes the problem.