leecalcars

iTrader: (37)

Going to try this tommorow to see if i have a faulty maf wish me luck!

http://www.scoobypedia.co.uk/index.p...eadingECUCodes

tim's wrx

One of these makes the job a lot easier. Everyone was telling me that I had a problem with MAF but this scanner homed in on a faulty idle valve!!

http://cgi.ebay.co.uk/Car-Diagnostic...item519365755d

374UkTurbo

iTrader: (1)

I wouldnt bother with a code reader on a MY99/00 car, the black and green connectors under the dash will work fine.. thats what they are there for. FYI maf is code 23 which will be 2 long flashes and 3 short flashes. Failing that download ecu explorer (free) and buy a vagcom usb/obd cable, they sell for around a 10er on ebay.

Splitpin

That won't work on a classic so would be a complete waste of money. 374's comments are correct.

Lee - has your check engine light been coming on while you've been driving? If not you will not find any codes stored when you connect the black plugs. Under most circumstances failing MAF sensors do not trigger the error so even if yours is on its way out, the ECU won't actually notice until it is totally gone.

Even if you get the all clear when you connect the black plugs, this is not, in itself, a guarantee that everything under the bonnet is 100% healthy. If you suspect your airflow meter is dodgy, there are better ways to test it.

leecalcars

iTrader: (37)

how?

leecalcars

iTrader: (37)

no check engine light has come on ,cars very hesitant ,holding back even,should i just change the maf to be sure to eliminate it if reading the codes wont find it till its not working properly.

Splitpin

Yes, I was going to say that if you don't have any test equipment, one way to test for a potentially dodgy one is to fit a new genuine replacement, reset the ECU, and see if the problem goes away. If it's immediately cured, you know what the problem was. If it's exactly the same, take the new sensor out and leave it on your shelf for the next time you're in the same boat.

The other practical way to test it is to log its behaviour with - as 374 said, a £20 diagnostic cable, a laptop and some free software. Let us know if you're going to do that and we can tell you what sort of things to look for. Or, you could just take the car to your local specialist/reputable mapper and have them diagnose it for you. Cost is likely to be lower (and the fix quicker) than speculatively replacing parts.

374UkTurbo

iTrader: (1)

Splitpin will no doubt have a better answer but if the problem is happening all the time id run the car while data logging and look for any irregularities with the maf sensor voltage, from what i understand the sensor voltage should increase with engine rpm, when my maf failed the sensor voltage stayed constant at 1.033volts thoughout the rev range indicating a faulty maf

374UkTurbo

iTrader: (1)

AHH you beat me to it Splitpin

leecalcars

iTrader: (37)

was thinking of a remap with jolly green monster as he travels,he would find the fault straight away im sure will contact him for an appointment has anyone his phone number ?

374UkTurbo

iTrader: (1)

If the fault is occurring all the time then yes the likes of JGM should be able to trace the fault easily however if its an intermittent fault that only happens once in a while it may be a little more difficult. Im not sure about SN but other forums im on dont like people posting phone numbers, here is JGM's site http://www.jollygreenmonster.com im sure you'l find it on there.

Splitpin

Yes, Simon will find it for you quick - but if you're not seeing him in the next couple of days I would either not drive the car at all (and if you have to use it, drive like a nun), or try an elective sensor replacement. Driving round on a potentially dodgy one is a recipe for engine damage. More to the point, if it's not the airflow sensor, and you've booked in with Simon, he may not have the parts to get the car running well enough to map it. Either way, if you can sort if yourself ASAP, so much the better.

Also, if you have an MY99-00 car, check to see whether there's a stripe of green paint across the top of the sensor's mounting flange. If there isn't, your sensor is at least six years old, so buy a new one. If there is a green stripe, either use a mirror, or gently remove the sensor and check for a four digit code printed in white ink on the lower part of the flange. If the first digit of that code is any smaller than than 8, again I'd suggest electively replacing it.

If you do fit a new sensor it's important to reset the ECU prior to driving on it.

JGM's details here.

leecalcars

iTrader: (37)

to reset the ecu do you simply just dissconect the battery,what price should i be looking to pay for a new maf sensor.

leecalcars

iTrader: (37)

connected the green and black conectors together for an ecu reset and nothing happening no ignition lights or anything !

leecalcars

iTrader: (37)

no cel ,no speedo,no rev counter ,no clock ,but engines running no lights !

leecalcars

iTrader: (37)

engine starting but fan is on, no indicators,no heater blow fan no rev counter,think its in limp mode,and wont reset ,no cel light on ,flashing or other wise need to ring jgm.

Jolly Green Monster

iTrader: (4)

sounds like you have managed to blow a fuse..

either connected the wrong connectors or just a concidence.. when the green connectors are connected it pulses everything so if you had for example a lower rated fuse than tyou should have it could blow with the added load etc..

check internal fuse box for a blown fuse.

Simon

leecalcars

iTrader: (37)

correct 15a fuse blown all working again.thanks simon

Jolly Green Monster

iTrader: (4)

nice one