240ez

Z U L8R

The ecu uses it's 1 and 120 degree signals to know the motor is spinning so it will give the fuel pump relay the ground it needs to keep the fuel pump running.

It also uses these signals to sequentially fire the injectors and coil packs by giving them the ground pulses they need.

The firing order is 1,5,3,6,2,4

without the signals from the cam angle sensor your ecu would not know the motor is spinning let alone what cylinders at tdc and when.

Without it you would get no fuel pump, no spark and no fuel squirting from the injectors.

Hope that helps

Dave

__________________
RB25 280z GT30/76R 441hp/381tq [email protected]

240ez

Thanks for the info bro. Is there a way I determine whether it works or not, or would I have to get another one.

Z U L8R

there is. turn the key on and spin it with your fingers and you should hear the injectors clicking and the coil packs making weird zzzz noises when each one fires.

basically it's got 4 wires. 2 are the signals, the white one is 12volt ignition power, and the black is the ground.

if it's got power, ground, and the 2 signal wires have continuity back to the ecu, then when you power it up and the ecu by turning the key to the ON position, as you spin it, it will think the motor's running so you'll hear the fuel pump run, and you should hear the injectors and coil packs clicking.

if none of this happens, then you could have a bad cas, you could have a bad ecu, or what it most likely is, bad wiring.

Dave

__________________
RB25 280z GT30/76R 441hp/381tq [email protected]

240ez

Alright. Appreciate the help bro.
Thanks.

eklips3

holy .. i didnt even know that

this is with the cas clip plugged in right ?

__________________

1992 240sx (RB20. [email protected])

Z U L8R

cas unbolted from exhaust cam , plugged into the harness, and key ON.

correct

dave

__________________
RB25 280z GT30/76R 441hp/381tq [email protected]

240ez

I tested it today and as i spun the (CAS) , i heard the fuel fowing through the lines, i heard clicking from the fuel injectors, but no buzzing from the coilpacks (got brand new set of six coilpacks).
Could it be that i have some bad wiring to my coils?

eklips3

could be a bad ground or a bad ignitor chip.

to check your ground there is a little ring close to the 6th coil pack. check it out, if its dirty then take some sand paper to it and give it a good clean on all contacting surfaces.

__________________

1992 240sx (RB20. [email protected])

240ez

Ok ill check that ground ring. What about the ignitor chip?
Its that small block on the back of the valve cover right?
What exactly does that do?

eklips3

yeah its that small block .

it receives signals from the ecu in ( ecu is saying which cylinder is to fire at which moment ) anyways it takes that signal and amplifies the power and sends it to the coil packs.

__________________

1992 240sx (RB20. [email protected])

240ez

Z U L8R

right on! it amplifies the ground signal to each coil pack.

you could even use a test light to test it and see if it's working correctly.

grab your 12volt circuit safe test light. put the aligator clip on the POSITIVE battery terminal or the back of the alternator charge post. anytime you touch your test light to a ground you will see it light up.

unplug your coil pack. you'll see the 3 wires going to the coil pack. cylinder 1 may have 2 blacks and 1 white. in any case, white would be your key ON 12 volt power supply. one of the blacks is your constant ground, and the last left over wire is your signal wire from the ignitor.

this is the wire you're going to test with your test light. spin the motor over, or spin the cam angle sensor with the key on and with your test light probed on that signal wire, if the ignitor is working correctly each time the signal for that coil pack is sent to fire it, your test light will flicker. if you don't get a flicker, then you can deduce that your ignitor is bad.

some places call it a "power transisting unit" or "PTU". some places call it an "ignitor" or "ignition control module" but it's all the same thing.

an rb25 ignitor is the same as a z32 (93 300zx)

the rb20 ignitors are different. the ground is located in the middle. it says G. you COULD use a z32 ignitor but you'll need the plugs and you'll need to wire them in.....actually....you MAY be able to plug your rb20 plugs into a z32 ignitor but you'll DEFINITELY need to repin it so the ground is in the correct spot, or you'll fry a coil pack cause it'll have a ground constantly.

.....or you could just put another rb20 ignitor on there and be done with it. lol

best of luck, hope that helped

Dave

__________________
RB25 280z GT30/76R 441hp/381tq [email protected]

240ez

hiboost123

whenever i crank the engine i would get sparks but no injector pulse, the fuel pump comes on and the eccs relay would make a click sound every 5 seconds. i was looking on the engine to see if i could locate the crank sensor but cant seems to find it. i really need help

Sileighty_85

Circled in Red

__________________
後輪駆動車１番
1989 Built SR GT2871R -363whp
1998 S14 W/RB25- 250ish (For Now)
1986 SR86 - 200ish
1990 R32 GTR - 320hp
Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html
Don't Buy XS-Power or SSAC Shit

fender-startocaster

good info on testing! will keep in mind.

nick b

hey dave

i have a rb20det cas with square plug but i have upgraded to a rb25de+t an re-loomed to a round plug loom? can i re-wire it to a square an will it still work the same from a 20det to a 25de+t, Im new to the whole rb scene an Ive been asked about vvti or something im not sure?

main question is can i use factory rb20det ecu an loom on the rb25de+t an just change plugs to fit as i need?

Thanks