afc issues~ Please Help! on Ka24de motor

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SpeedyZman
Posts: 19
Joined: Wed Feb 18, 2004 7:21 am
Car: anything turbocharged
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I was needing to do the install to correct my car running WAY too rich.... I asume it is running rich as I have removed allmost all the vacuum lines and egr stuff using block-off plates and blockoff plugs to clean up the engine bay as well as removing anything unneeded such as doing the throttle body water hose bypass removing the hoses and also the metal hoses and vacuum lines that run thru the intake plenum and behind the engine including the swirl control valve---- (which I still am wondering what that does!) It's to be an autocross car and I'ts been COMPLETELY gutted,.....no ac/heat/even removed all the insulation on the firewall.....everythings been removed and cleaned before installing the motor as this was a flood car previously,,,,,, I've got the other features of the AFC working great including the Rev meter & the Throttle %..... I'd like to get that afc install completed asap to cure the car from running way too rich,......its blowing black smoke ..... (spark plugs black with soot as well thus the diagnosis) as the engine was running great when it had all the emissions stuff intact,,,,,

the car actually seems to idle better when you unplug the maf sensor as well- but thats probably due to the ecu receiving the incorrect signal of 5+volts instead of around 1.3 or so at idle....

I've got the afc set on 5in 5out as the us manual update stated the ka24de motor was a hw-5 sensor model.

I also swapped a known good afm from another s13 i own to make sure that wasn't the problem and it does the same thing.

the AFC keeps showing I'm at 100% airflow even when the car isn't turned on (key in accesory position) due to the 5+volt signal from the white AFM sensor wire,....

Please HELP me figure this thing out as it's driving me crazy!!!! thanks in advance for the help!Damon 417-860-8710


S13240
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Joined: Fri Jul 26, 2002 8:06 am

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I think you have it set wrong. Suppose to be 1 in 1 out. And cylinder is 4 with arrow pointing UP! Hope that helps

SpeedyZman
Posts: 19
Joined: Wed Feb 18, 2004 7:21 am
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I have the cylinders correct in the afc unit as 4 with the arrow up as well..... I've tried numerous settings but from what I read it needs to be 5in 5out according to the latest afc downloadable documtation from apexi.......

I think there may be a bad ground or possibly a short somewhere in my cars wiring as I should NOT be getting a 5volt signal from the afm signal wire when the car isnt even running.....

thanks for your input and I'lltry the 1 in 1out setting just to be sure ---- but I think the ka24de is labeled as an hw-5 sensor which denotes the 5in 5out setting.....

any other advice is greatly appreciated......

I'm thinking about using a z32 maf with it instead and have been told to set the afc as a 2 in 5out setting,.....

any confirmation on that would be great....thanks again!Damon

S13240
Posts: 1908
Joined: Fri Jul 26, 2002 8:06 am

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Is this on afc or afc 2? I'll check tomorrow when I get back home from work in my manual. Looks like you have something wired up wrong or set wrong. I suggest you to check all your wiring at the ecu again and redo your initial start up setting.

SpeedyZman
Posts: 19
Joined: Wed Feb 18, 2004 7:21 am
Car: anything turbocharged
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the maf ground had gone bad somehow....

the Black wire on the maf connection wasn't showing that it was properly grounded when I did a continuity test between it and the negative terminal.....

so I then hardwired a new ground wire to the black wire and walla! it was showing the correct voltage and now the afc seems to read correctly.....

that was it!

I am now trying to find a correct wiring diagram for the z32 maf so I can wire it up to the car now.....

if anyone has a known good diagram please post it!

Many thanks to those that responded!Damon

SloS13
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