I need Help!!!!!!!! No injector pulse!!!!

[darkstar575]

1990 s13 5spd rb20det. I finally have spark. Connected the bulb thing to the injector clip and nothing. I have a few questions...1. Where the f... is the engine harness ground? 1 writeup says to connect it, another says nothing. I'm following skillzillas writeup. Is there a wire that controls the injectors that I could directly connect to 12v switched?2. How does the harness get power? My ecu lights up and my relays click. My relays will also buzz when I turn the key after trying to crank it.3. The white/purple-green/yellow...is showing 7.4with negative terminal connected. Shows 13.6v with negative battery terminal disconnected.black/red-black/red reads 13.6. All with key forward.4. Ecu light goes off when engine turns over. Comes back on when i roll key back. The dash dims when engine turns over as well...but isn't that normal.5. Engine sputters with starter fluid.6. This sucks balls, please help.

If anybody lives in the miami area that would be able to help me out with this. I am willing to pay. My name is Ivan and phone # is 30596515burnt ecu....
Modified by darkstar575 at 3:38 PM 8/1/2007

[darkstar575]

Still no injector pulse? What controls the injectors? I've searched my *** off and still have no answers!!!! Bump!!!

[silkysmoothyjud]

thats not an easy answer to just say in more ways than one, since the short may have blew out the ignition coils in your injectors.....I hope not

[darkstar575]

I jumped pins 101,103,105,110,112 for injectors 1-6 and they would all fire. Theres power in the harness but no pulse. The ecu just doesnt wanto give the pulse out to ground each injector. My cgi relay started buzzing when trying to crank the car and the light on the ecu went out...so I pulled the ecu and found a burnt copper connection on the board it's self leading to pin 45 which is ignition power...Could this haVE CAUSED MY INJECTORS NOT TO FIRE THIS WHOLE TIME? I guess I need an ecu... anybody have an extra rb20det ecu, does anyone have recommendations on where to purchase one? Thanks!

[silkysmoothyjud]

holy ****, I pray Im freakin wrong this time!!

[S12_hybrid]

The way injectors work is they receive constant 12v and are GROUND activated. This means when the ecu grounds them they will open. SO in order to keep the injector closed when the ignition is on (But no Cam angle signal, if the engine isnt running) you need to provide NO voltage across the injector - this means putting 12v at both sides.

So, find the pin that 'activates' your main relay and ON THE ECU CLIP insert a wire and ground it to the chassis (Assuming the main relay is ground activated - like on the RB25)

Once you've activated the relay, power will be provided to the engine harness. You've got to check all the injector ground pins (all 6) to make sure they read 12 volts.

What you've got the make SURE you havent done is connected the injector 12v source (l/b wire on RB25) to a ignition source whichs turns OFF when on start (accessories, wipers, etc - they all dont work when the key goes to start). If you dont power your injectors in start obviously the car will not start.

Good luck.

-Dan

[darkstar575]

I wired it to a green/yellow wire that was showing 12v in the start position and 0 in the off position and I swore my dumbass friend who helped me for ten minutes accidently turnd on my wipers. I'm going to double check that. The wierd thing is that all the ecu pins for the injectors didn't show any power...They were all at 0. When I grounded the pins individually they would open the injectors. I'm going to try grounding the main relay ( I have no Idea on doing this...) but I'm going to give it a try. My green relays buzz after trying to crank the car. Thanks for your help I need new ideas to get this thing to crank!

[darkstar575]

After posting I looked for the ignition switch relay pin...I found pin 45 (ign) ignition switch (ign)...thats the one that shorted out. When I took apart the ecu the copper "road" about 1 inch from the pin leading to pin 45 was blown. Then the ecu had no power whatsoever. I'm going to get a new ecu and put a 5 amp fuse in the line to keep it from popping my ecu...see if it starts then. If I grounded pin 45 for ignition wouldnt that mess it up...it should show 12v then if I groun it wouldnt it kill the ecu?