Hi All,

A few months ago I replaced the MAF on my UK MY99 as it was causing the car to lean out after 3200 revs (hence 3 engine replacements). The difference was amazing and immediate.
However, I am concerned that the MAF which my local Subaru dealer conveniently had in stock was actually knackered too (knackered in a different way to mine).

When the car is started for the first time, it ticks over at around 1400 revs. For the first 3 or 4 minutes whilst the choke is on, the car "pulses" when you accelerate steadily or hold the revs to go forward slowly.

It ticks over perfectly, when you put your foot down its
great, but is this pulsing (just noticible) normal ???

Thanks.

 

i think its normal
sumthing about closed loop and open loop or sumthing

mine does it when cold, im sure most peoples do as well

 

I have a MY99 mine does exactly the same when cold, rock solid when warm, just had my MAF replaced for poor idle when warm, have you had 3 engines fail due to MAF? or other problems.

 

Just been through the same maf questions with my sti4. revs up and down a bit from cold, was lumpy too even when warm. Has had a new oxygen sensor and a set of plugs, different car. I'm told maf is ok, emissions checked right through throttle / rev range and all ok.

 

The dealer and subaru warranties inspector blamed it on ecu failure!! It had never run correctly from the day I brought it. Idle was grate at all temps, it was leaning out over 3200 which the standard Subaru Diagnostics did not pick up. New MAF fixed it all !!!

Subaru will not re-inburse me for the MAF as they say the standard subaru diagnostics equipment would have picked up a fault if there was one and that a rolling road is not required to establish if a maf if faulty or not !!!

Nutters !!

Ta. C

 

The diagnostic software won't pick up a failing MAF most of the time, i.e. come up as a fault code. The "lazy" dealers should take your car for a run with the select monitor connected and observe the O2 sensor readings to determine if the car is running lean. This is the right way to do a diagnostic check on a MAF. Not just plug it in and wait for an error code.

Cheers,

George.

 

Thanks...

 

I had problems convincing my own Dealer that my O2 sensor was faulty. John Banks kindly checked it out on DeltaDash and you could clearly see it flatlining around 0.3volts on idle - it should move up and down in a nice wave pattern.

Since I also had a 32 ECU fault code, I told the Dealer I reckoned it was a duff O2 sensor. They immediately asked if I'd changed the exhaust (the service the damn thing so know I hadn't), then when I hassled them they stuck it on the select monitor (or so they told me).

They said it should up no errors, then when I asked them if the voltage was a flatline or moving up and down in a nice wave, they said 'hold on' we'll confirm. 10mins later the come back and say, yeah you're correct it's fubar'd.

Dealers are just lazy and you need to constantly hound them to get something diagnosed properly.

Stefan

 

Edited just to say I would change dealer if I were you

Can't believe they let you blow 3 engines

[Edited by SiPie - 6/12/2003 2:17:58 PM]