20b_silvia

Hi,

Was getting ready to fire up my 20b motor on a test stand, as soon as I connected the negative to the battery terminal the starter motor began to kick over so I disconnected it until I find out some more info. Before I rule out a possible faulty starter solenoid I wanted to find out some more info...

Regarding the wiring to the ignition key, can anyone assist me with this?

I have the three harness that go from the drivers side firewall (from fuse box) into the joint box, I can only assume that a number of these wires will be used for the ignition.

I have a generic 4 switch ignition that has;
BATT
START
IGN
ACC

Now, my question is, can someone identify from the looms which wires go to these ignition switch?

Pics of harnesses that connect via joint box and other wiring under the dash,



I have the 20b wiring diagram but its all in japanese and I cannot make out the markings for colour coding which sucks!

Thanks

20b_silvia

Anyone know?

t-von

iTrader: (8)

You not gonna get much help here with Cosmo Wiring harness because we all wire in our own ecu's.

What ecu you planning on running?

I've actually run my own 20b on a test stand with an aftermarket ecu. So I have some experience doing this.


You don't need an the ignition key to make it run. Your gonna have to locate both the ecu 12v supply and ign switch 12v to turn the ecu on. Then make sure the all the relays to the fuel pump and coils have 12volts. You can just wire these direct to a battery. Disconnect the 12v supply to the starter solenoid and jump that directly from the larger gauge starter wire (that should also be hooked to a battery) when your ready to turn the engine over. If you get spark as it turns over, it should run if you have decent compression (80psi or higher)and fuel.

20b_silvia

hi,

thanks for that. starting to get my head around it now. i am running standard ecu for the moment so i can do a compression test before deciding so rebuild while its out or get the motor in a car for engineering purposes. i will see how things go after the next few days.

20b_silvia

Got spark, seems as though fuel injectors aren't opening as no fuel is going inside the motor so I will take them out and get them cleaned.

20b_silvia

One last question before having injectors removed.
If I am getting spark to the plugs then should I also be getting fuel flow from the injectors?
Would I have bypassed the egi relay and fuel pump relay using the above method? or would having spark suggest the egi relay is working normally and the injectors are clogged / not functioning?

t-von

iTrader: (8)

I don't know how the EGI wiring is set-up on that harness. You can try jumping powering it up to see what happens. Basically you have relays that send 12v to the coils and fuel system. On the other side of the those connectors, you have signal input from the ECU that controls them. The injectors need the trigger signal from the CAS to start injecting. Same as the coils. The CAS actually tells the ecu that the engine is turning. If you got spark from the coils, then you have proper CAS reading. So you need to make sure you actually have power to the injectors themselves. If you have power, then they should be injecting fuel (profided that they aren't stuck closed).

20b_silvia

All sorted, got power to the injectors now and I can hear them clicking. I am charging a 12v battery but it only has about 550cca so not too sure if its stong enough to crank it to a decent RPM but I'll see.

I'll post back later with how it goes, if it goes at all that is...

t-von

iTrader: (8)

That battery is plenty. I used a Miata battery to fire mine up (450cca). Just make sure your battery doesn't have a bad cell or too much voltage drop while cranking. If the cranking voltage drops too low, the coils wont fire properly and you will flood the engine. I would definitely hook up a multimeter to the battery while you turn it over over to check the cranking voltage to be safe.

20b_silvia

Well some good news, the motor fires up but only runs for about 5 or so seconds before shutting itself down.

Far out they sound amazing!

t-von

iTrader: (8)

Yes they do!

http://www.youtube.com/watch?v=ND6xJkwFAFk

20b_silvia

rough but it runs...

http://www.youtube.com/watch?v=BuKnWjGE6Jo

20b_silvia

http://www.youtube.com/watch?v=xvGnPFCYmyY



needs a couple of gaskets...

t-von

iTrader: (8)

Orgamsic isn't it?