4age 20v ST vehicle speed sensor reference for Standard ECU

[Twisty92]

Car- ae86 sprinter
motor - 4age 20v ST from ae101

Hey all i am running a standard ECU for my ST
i am trying to hook up a vehicle speed sensor so i don't have the 7200 rpm limit / fail safe mode on all the time

i will be purchasing vehicle speed sensor piggy back adaptor for my T50 trans to give the ecu what it wants, how ever i need to find out what pulse per revolution does the standard vehicle speed sensor put out from the ae101?

i have tried connecting reed switch from my cluster to ecu but with no luck,

i have read 3 different pulses that it could be from sources off the net.
2 pulse/ per rev
4 pulse / per rev
and 10 pulse/ per rev

if anyone could confirm which it is , that would be fantastic!
i am dieing to drive my 86

[Matt]

Normally grabbing the reed off the back of the cluster works fine.

[Twisty92]

Thanks matt

have tried this again, still no go.

i'm not saying your wrong possibly my ecu may have a fault?

but the signal from the reed switch is a on/off earthing switch, where as the original one is 3 wire with roughly 10v coming out of it? with a positive dc wave

i don't see how it can work...

[the witzl]

im sure people have used the cluster SPD output from the AE86 before....
Otherwise a basic pull down transistor circuit using the reed switch would work. Im sure some google will answer this one.


EDIT - googles says it should work with SPD on the ecu connected straight to the cluster's output.

[Twisty92]

So this morning i've finally had time to try this scenario out again, cluster output to ecu...this time i even ran an additional earth wire from the cluster above where reed switch output is

Still no better, however this morning it wouldn't even go past 6200 rpm....i unhooked the wire completely then it wouldn't go past 5800rpm..didn't even sound like a 20v!

but i think i may have found the problem took the ecu apart and pretty sure i found a leaky capacitor



anyone else think this will be the problem?

[the witzl]

Leaky capacitors certainly will feck it up.
I wrote a guide to fix them on the toymods.

Check it out there.

Also looks like you have some damage to the tracks, so might want to check it out thoroughly

[Twisty92]

Cheers man, will have to look into it alright.. took a 2nd look this afternoon at the ecu. Looks like the cap hasn't leaked but that section has burn't out

[Matt]

There is a guy in qld that'll replace the caps for you fairly cheaply in runcorn.

Ill pm you his details if you are keen

[Twisty92]

Thanks matt, much appreciated

i will be taking the ecu with me to work tomorrow to see if any other techs can help me diagnose, its really odd but it looks burn't out not caps.
i've driven the car maybe 3-4 times since i've owned it and as time goes on i guess it does more and more weird stuff!?