Oxygen?? MAF?? Hmm!!

[Phil Charman]

Hi again!

Well i have changed my oxygen sensor (Lambda) & MAF on my HGT & guess what?? It still missfires when cold! This is just weird! So I've done the following:

Oxygen sensor (Lambda) - Replaced 2 days ago
MAF sensor - Replaced last night
New SPark plugs - replaced 3 months ago
Coil Packs - Checked 3 months ago & all fine.

So im thinking its maybe fuel?? I just dont know, so my HGT is going into an independent specialist next week who said he'll have it for 3 days to find out whats wrong with it.

What i dont get is that no warning lights were on at all, except now since new MAF has gone in last night, a warning light has come on, its like a fuel injector warning light & it hasn't gone out, not sure why. I know it needs to learn the new sensor, but is it meant to stay on???? Bloody trivial things like this are frustrating. Anybody else have these sort of probs?

 

[marko]

The warning light you mention is just a "take me for a diagnostic" indicator.
Get the car to a specialist (anyone other than FIAT dealership) and have them plug it in.

 

[Jayfish]

I know it sounds daft but make sure your MAF is in the right way round, it should have an arrow on top pointing left (if you cant see the arrow it's because you've got in in upside down)
..not that I've ever done it...

 

[Von]

We put a new MAF on yesterday. There is a sequence with the ignition key that you have to go through to get the car to recognise it, then the light should go out. Tim is at work, so if you want the sequence (as got from the workshop manual) let me know and I will post it later on today.

Von

PS. HGT going well now, fingers crossed.

 

[Phil]

Sensor problems & warning light

Yeah Von if you could send me the sequence, much appreciated, I didn't realise you had to do it a certain way, because I just started my engine with new one in, but the warning light just stayed on, almost like it didn't recognise one being there.

Lol! to putting one in the wrong way! I actually thought you could only put it in one way, but its worth checking to see if I have

I hope this gets sorted soon, its been going on for while now.

Cheers guys

 

[Von]

It may be best to unplug the MAF and replug in just before doing this.

Sequence as follows......

-turn ignition switch to ON
-wait fo approx 30 seconds+: the control unit should carry out a self learning cycle
-turn the ignition key to off position
-carry out a fault diagnosis

FAULT DIAGNOSIS

Using the heater controls (on my HGT this works)

-turn the left knob completely in a clockwise direction (HI position)
-turn the right knob completely in a clockwise direction (MAX DEF position)
-turn the centre knob to position 0
-turn the ignition key from the OFF position to the ON position
-within 10 seconds, turn the centre knob, placing it in the following positions:
0 AUTO 0 AUTO 0

If there is still an error it will show up on the LCD display. If there are no faults Cli should appear on the display.

When Tim did this it didn't work first time and he did the first bit again leaving it a bit longer than 30 seconds.

Good Luck

Von