Afm Giving Different Voltages?

[silver gts-t]

today my car was getting tunned and everything was running sweet then the AFM started giving out different reading..

no im no expert so im trying to repeat what i have been told.

A faulty AFM i have been told will give a very high or low reading, well mine was going up then down then centre...?

the tunner has never seen it before in all his time remapping ECU's (which he was doing with mine)

so basically he said even a 0.1 volt can make a massive difference in the high end voltage.

anyone had this happen before, or any tips?

(we are going to try a different z32 tomorrow)

disclaimer: if i sound like i dont know what im talking about its because i dont, just relaying info.

thanks

[silver gts-t]

another note, the car doesnt idle properly..

it hunts and sounds lumpy

[silver gts-t]

i remembered something else, supposedly the ecu sences a problem and instead of running 1 bar it thinks its running lower boost and advances timing alot, and causes detonation

[paulr33]

stock ecu has no concept of how much boost you are running.

does the afm voltage vary much at idle? if its hunting around then the afm will vary a little as it will suck in a bit more air when it tries to stall recover. is it a new z32 or 2nd hand ? do u know when it last worked ok?

[silver gts-t]

stock ecu has no concept of how much boost you are running.

does the afm voltage vary much at idle? if its hunting around then the afm will vary a little as it will suck in a bit more air when it tries to stall recover. is it a new z32 or 2nd hand ? do u know when it last worked ok?

<{POST_SNAPBACK}>

it was 2nd hand, i was told the voltage varies constantly, then later in the day was sitting in centre..

i was also told that when a particular sensor was turned off via ECU tunning there was no detonation

[silver gts-t]

anyone?

[shif_tea]

bad connection to the AFM?? If you're getting the resistance changing slightely in the wiring or connector you'll get voltage drops that will mess with the comp.

Dunno but its something to check out.

[Sydneykid]

Gotta POD? Dirty AFM, try cleaning it with spray on brake cleaner.

cheers

[silver gts-t]

on one of the wires there seemed to be this insulation tube over it..

could this be the cause?

[silver gts-t]

Gotta POD?  Dirty AFM, try cleaning it with spray on brake cleaner.

cheers

<{POST_SNAPBACK}>

already tried cleaning it, nothing...

[yogi000]

by moving the wires about do any of the voltage readings change??

hows the car coming along??

[silver gts-t]

by moving the wires about do any of the voltage readings change??

hows the car coming along??

<{POST_SNAPBACK}>

ill have a play around with the wires tonight, cars fine apart from this..

a touch laggy

if it doesnt get fixed after trying a new AFM i quite the whole remap ECU route

[silver gts-t]

any other ideas?

[Duncan]

nothing wrong with a remapped ECU mate, you just need the sensors to tell it the right things....but I'm not 100% sure from how you described it.

Do you have a consult cable? datascan and similar show great data on the health of all the sensors to help you track down problems.

[silver gts-t]

nothing wrong with a remapped ECU mate, you just need the sensors to tell it the right things....but I'm not 100% sure from how you described it.

Do you have a consult cable? datascan and similar show great data on the health of all the sensors to help you track down problems.

<{POST_SNAPBACK}>

im not sure either...

i dont have a consult cable.

last night we tested 4 z32 AFM's on a 180sx

mine and another were giving out different readings, the other 2 were practically the same.

mine was running the 180 rich

[RB30-POWER]

I would be checking that the AFM is getting a nice constant supply voltage.

I would check that with the airflow meter disconnected that it reads low volts <1V and sits constant until i blew through it to jump it to >2V. (Need bench power supply connected of course)

I would disconnect the harness and measure resistance/check continuity through the signal wires to the AFM. (make sure there is not bad connections or piggyback devices hidden in the system)

I would do the wiggle test over all connections.

I would subtitute a 0-5V supply through the signal wire and check with a suitable consult/scan tool, that the reading did not fluctuate on the scantool hooked to the ECU itself.

All whilst measuring the actual voltages at the ecu end with a multimeter to see what was actually going on.

Well thats what i would do, coming from an auto elec.

Sorry if none of it makes sense, but if your tuner does not do the above, he will never know or rule shit out.

Shouldn't be to hard to sus it out, if he cant take it to someone else.

[silver gts-t]

will pass on the info!

thanks!

I would be checking that the AFM is getting a nice constant supply voltage.

I would check that with the airflow meter disconnected that it reads low volts <1V and sits constant until i blew through it to jump it to >2V. (Need bench power supply connected of course)

I would disconnect the harness and measure resistance/check continuity through the signal wires to the AFM. (make sure there is not bad connections or piggyback devices hidden in the system)

I would do the wiggle test over all connections.

I would subtitute a 0-5V supply through the signal wire and check with a suitable consult/scan tool, that the reading did not fluctuate on the scantool hooked to the ECU itself.

All whilst measuring the actual voltages at the ecu end with a multimeter to see what was actually going on.

Well thats what i would do, coming from an auto elec.

Sorry if none of it makes sense, but if your tuner does not do the above, he will never know or rule shit out.

Shouldn't be to hard to sus it out, if he cant take it to someone else.

<{POST_SNAPBACK}>