BoostForLife

Okay, so my neighbor picked up a DA that runs like ----.
I have checked the timing belt and spark. When we put new plugs in and ran the motor a couple of times, the plug for cyl #3 is still brand new. cyl #4 looks a little used, and #1,2 look normal. So, basically the motor doesn't make much power and runs rough.
I have tried checking with a different perfectly working ecu, and nothing. Checked A5 pinout from the both of the ecus and only got a signal out of it once. Never again did it send any signal. Though it burned my ecu too, so put my map onto it and ran my car perfect.
Im just looking for ideas, before I start messing with the yellow main common wires.
By the way I have tried using a different set of injectors.

txdohczc

so if the ecu is puting out a signal and it is not making it to the injector then you have either a loose connection somewhere or a short somewhere. all you can do is do what everybody does and find the short/connection and fix it

BoostForLife

I have only got a signal out of the ecu once and never again. I have tried running a wire from pin A5 directly to the blue wire on the injector #3 clip, and still nothing because I have not got another signal from it.

Zeniceguycrx

your injector signal is ground, youcant just check it with a test light.
power go into the injector and then triggered by a ground pulse, you need a noid light

BoostForLife

I have used the pinout from here.
http://www.superhonda.com/forum/f55/...inouts-217405/

All of the injectors have battery voltage when engine is off but the key is on. I will try to test inj#1 and #2 and see what happens. The link above says that with the key on and engine off the signals are battery voltage. I did get signal once by putting the positive onto the signal and negative onto the body and it worked once.

I think I should test the common wires too and see how they are.

CXyD

Try switching injectors around or get another set and swap them out and see what happens. Did you try disconnecting one injector at a time to see if the idle changes. When you disconnect the third (possible problem inj.) I suspect you'll notice no difference in idle. Then swap the inj. and see if the idle gets better. If it doesn't then you may need to look at the wiring. You should be able to narrow this down in less than thirty min.

fuse

You should have 12 volts on one wire of the injector. The other do an ohm test from the injector wire to the ecu (both unplugged) You should see 0 ohms. If you see infinite/ofl you have an open.

Take one lead to ground and one lead the wire you should see infinite/ofl ohms (this tests for a short to ground). If you see 0 ohms you have a short to ground.

You can not test for a signal from the ecu it dose not send 12 volts is supplies a ground for the injector.

It could also be bad compression in that cylinder. Valves adjusted tight on the cylinder or way loose. Spark not getting to the cylinders. Fuel pressure not getting to that injector. Clogged exhausted runner on that cylinder. Bad injector on that cylinder. Bla bla………………

BoostForLife

It's already narrowed down, i have already changed the injectors, tried disconnecting the clip and so on. It's already narrowed down.

The comression is good, injector is not spraying at all due to no power to it, tried different injectors already.
I will use your idea and test for shorts in the signal wire. Do the common wires give off power with key on engine off? IF so, then I will need to test those too. Thanks again.

stenseltizm

what year da? On the drivers side, there will either be a dead end plug (92-93), or a resistor box(90-91). One wire from each injector will go to this plug and have 12V with koeo. The other wire from each injector will go to the ecu as mentioned above. The injector supplies a ground to 'fire' the injector.

BoostForLife

It's 93. So it's OBD1. I know about the plug cuz had to install resistor box into my del sol. Thanks again for the answer. I will test these tomorrow.