Wanted: 20V 4age expert!! QLD

[JP]

The AFM has the FC switch built into it which triggers the Circuit Opening Relay which then entergises the fuel circuit.

[Jason Broadhurst]

Well, both that and the analog out worked for me when I left that car. It was also starting and running frequently aswell. Makes me think that the AFM is being temermental and isn't working again now.

[thechuckster]

i fixed Circuit Opening Relay wiring (was fed with batt power so even without the key in the ignition, you could trigger the fuel pump by shoving your fingers down the AFM. Injectors were also seeing battery power so they're now fed from a relay that's triggered by the ignition switch.

We got the car running (on all 4 cyls) by shoving a finger down the AFM to open it up (and removing the AFM from the airflow.

With the AFM as is, it sounded like it was running on two cylinders.

I can't remember if we tried the finger-in-AFM trick with it still in the air path to the throttles.

I put the multimeter on the AFM and I got varying resistance (lowered as vane opened) from the AFM and to vRef (edit: i think that's what it was), but open circuit from vRef to AFM earth (which isn't shared between the air temp sensor). My gut feeling is that the AFM is snaffu.

[connection]

so if you kept your finger in the AFM, with it running on 4 cylinders... what happend if you gave it some throttle/ revved it?

did it instantly die? or stutter and struggle to stay running?

[thechuckster]

struggled a bit until i pushed in a bit more or 'Buttocks' pushed on the throttle.

[connection]

so if it will stay alive when you give it some throttle, did you take it around the block to get a better idea on WTF its doing?

[thechuckster]

nope - arse of car was up in the air and time was not on our side.

As you had previously suggested - the wiring job was a cockup and to do the car justice, it really needs the motor ripping out and the loom re-done so it suits the engine bay and sensible stuff (like a diag port and a check engine light are included).

a return visit with electrically good Afm would be my next step

[skiddz]

spoken to jason ill be sending a spare afm of mine up on monday ill throw it in an express bag too bout the same price anyway

[Buttocks]

Just waiting for your info so i can give you some dosh, before you send
Thanks alot for that Skiddz

[Buttocks]

I just tried another Air FLow Meter, it made no difference it was the same result

[Buttocks]

Im gettting the distinct impression that the AFM might be wired wrong

[thechuckster]

given that some basic things were botched up (like how badly the circuit opening relay was done) i wouldn't be surprised.

[Buttocks]

Anytime you would like to come out, i'll make sure im here!
Need the damn thing to go so i can get the gearbox shifting and get the little bugger painted

[adamaw11]

Another thing i noticed, is when i got Jason to turn the key to "start" i would get a constant 12v coming out of the injectors, but when it ran by itself for those odd seconds, the volts drop drematically, almost asif that once you release the key from "start" back to IGN it stops giving power to the injectors. Seems very wack.

with a very brief look at this thread my guess is power to the AFM SENSOR.

I had a problem wiring up a 16v, there was no injector signal, and was only starting on the cold start injector, then dieing.

The AFM has a number of wires, I thought it was all correct, thought I new what each wire did, eventually realised one wire was to power the sensor circuit (or something like that IIRC) after connecting that one - bingo.

So find out exactly what each wire does that connects to the AFM, and make sure its doing it (i.e. earth, power, sensor signal, fuel pump switch etc)

[SL666]

Sounds like an AFM wiring issue.

With the AFM disconnected, the ecu is going to go into limp-home.. where its going to dump fuel into the engine related to throttle position, but generally hella-rich, once the AFM is connected, regardless of whether the wiring is around the right way or whatever its going to try an use it..

If you have cut the wiring between the AFM and the ecu at any point, i'd double check any joins - colour to colour sort of thing, and for a good connection and no shorting.

might be worth checking for voltages at the plug when the ignition is on?