therest

Have a 91 Hatch STD and started a LS swap in it. Im having trouble getting fuel out from my injectors. I get fuel to the fuel rail but not the injectors. I hear my pump working and also my main relay. I wired it by using the old injector plugs from my harness. Brown with the yellow and the light blue cable to the red. The other two to the ECU. I soldered a third wire to the two yellow/black wired from the two main n auxilary plugs to theyellow and black cable from the resistor box. I am using OBD0 injectors.

Now I've tried checking current in the injector wires and there is none to them. Not even the two yellow/black wires from the original harness. My question is can one injectornwith a bad connection or bad soldering cause all injectors not to work??

I thought it could be that my resistor box wasnt getting proper ground but i bolted it near the shock tower. any help is greatly appreciated! Also i geting a spark.

therest

anyone?

4drEF

If you have fuel to the rail, then you have fuel to the injectors.
They just aren't firing.

I'm not clear on your wiring.
Each injector has a power and a ground.
The power comes from the main relay (yellow/black wire), goes to the injector resistor box, and then splits into 4 wires that go to each injector.
A bad connection between the main relay and the injector resistor box will cause all the injectors to not fire.


The grounds run to individual pins on the ECU.

The distributor sends a signal to the ECU when to ground each injector to fire it.

F22Master

Check voltage between the red wire on each injector (the one from the resistor box) and ground. Should be battery voltage (12.--V).

Check the resistance of each injector ( put one prong from the meter to one pin in the injector, and the other prong to the other pin) they should be like 2-4 ohms i think.

Check continuity between each injector 'ground' wire, and the ECU pin it SHOULD go to.


If all of those check out, then make sure all of your wire harness connectors are fully seated. The big brown covered rectangular plug on the passenger side strut tower is ALWAYS giving me trouble. Use both hands to squeeze it together to make sure its connected.

Are you sure you're getting spark? Try spraying some lighter fluid into the intake manifold while cranking. The engine should be able to run (very roughly though) on starter fluid.

therest

Thanks a lot guys, I just went outside to check all the wires again. I am getting no voltage on the wires of the injectors. I am getting no voltage on the yellow/black wire either.

I put some gas in to the intake through a water sprayer two nights ago and it tried to start. I tried it again just now and got nothing. The sprayer isn't as good as the other night. So I am going to check once again in a little bit. My battery is slowly draining out. Sucks. I'm currently charging and going to check it out in a little. Gonna see if I got a spark through the plug wires. Thanks a lot guys. I've been down since the 22nd of Dec.

F22Master

Make sure the Black/Yellow wire from the resistor box goes to pin A15 at the ECU!

therest

I followed the other way of doing it. I soldered both the yellow/black wires from the Main Injector and Auxiliary Injector from my original harness, then soldered a third wire to it that connects to the Black/Yellow wire from the resistor box. With that said I soldered the Light Blue wire to the Red wire, and the Brown to the Yellow. The Red and Yellow come from the Main and Auxiliary Injectors.

therest

Also, I am now not even getting a spark. I don't get it. I had one just the other night.

F22Master

That way of wiring doesnt sound right...

Idk, when I did mine I added all the wires I needed. I didnt use any stock/existing wires. It's only 5 wires (for the injectors). And then you know they are right.

1 wire from pin A1 to #1 injector
1 wire from pin A3 to #2 injector
1 wire from pin A5 to #3 injector
1 wire from pin A7 to #4 injector
1 wire from pin A15 to the odd colored wire from the resistor box

1 wire from each injector to the resistor box

It's much more simple than it looks.

Also, did you switch your TPS wires?
Did you wire your dizzy plug correctly?

If you incorrectly wired your dizzy plug, you could have killed the ignitor. Happened to me!

4drEF

Spark and injectors are controlled by the distributor.
This doesn't necessarily mean your distributor is bad.
It could be that you don't have a ground wire secured properly.

Check all grounds including (but not only) the one going from passenger frame rail to transmission and the two lugs that screw down on the thermostat housing.

When you first put the key in and turn to the position just before cranking, does your check engine light come on for about 3 seconds and go off?

therest

Ok guys there is a little bit of information that I didn't give out that I totally forgot about. So my car has a wire running from my ignition in to my engine bay. It was always loose not connected to anything ever since I had the car. I found out early after installing my harness that it was a direct way to turn over the car without the key even in the ignition. With that said, earlier tonight I was trying to see if I had a spark by just touching the wire to the positive post of my battery. The car would crank but not start as usual. Then I thought I should put my key in, turn it to the where my dash lights are on and see if I get a spark. I ended up doing that and I realized that I did have a spark.

Now, I am off the just getting my injectors to get the signal to spray fuel. I followed this write up

http://www.b20vtec.com/forums/techni...-diagrams.html

I did extend all necessary plugs and have seen one or two other write ups done this way. I have however seen write ups of how F22Master says I should do my injector wiring. I am really tempted to do it this way however, I suspect that my problem MIGHT be from the wiring I did for injector #2 and #4 that go to the ECU in pin A3 and A7. You see when I was extending my wires to make it long enough to reach the ECU I used many different short pieces of wires...and well of course, a lot of solder connections. I don't like that. I get the feeling that maybe I could get a more sure current with just ONE long wire.

I did end up buying wire but ONLY did my CPS sensor wires (BLUE/GREEN and BLUE/YELLOW) with it since I already had my injectors wired, even if it was such a ghetto way of doing it.

That's way earlier I was asking if even one injector was wired wrong could it affect ALL four injectors not spraying fuel.

Other things to note:
#1. I am not happy how my Resistor Box is getting ground. Doesn't seem right. (It's bolted near the strut tower but looks funky. Also, if this isn't how the Resistor Box gets ground, then please disregard.)

#2. I don't have a very good ground to my Valve Cover either.

#3. I dislike how I haven't posted pics so ya can see what I'm talking about. I will try my best to get those asap.

F22Master

Not sure the resistor box needs ground.... Many people just let them hang free in the engine bay, or zip tie them under the intake manifold.

On the wiring:
I started in the car. Unpinned any pins I didnt need on my connectors, and added wire to pins i took from another donor car. Then I ran all my new wires into the engine bay.
I did all of my wiring with no engine in my car. The car was on blocks and I took a chair and sat in the engine bay and routed all my wires and did everything that way. MUCH easier. And that is the way I suggest anyone does it. It is possible to do with the engine in the car, but not as easy.

But like I said,

1: if there is continuity (the wires are connected) from each injector to the correct ECU pin
2: and the resistor box to A15
3: and a wire from each injector to the resistor box

then your injector wiring is done. Even if you used multiple pieces of wire, it should still work.

What about the ECU? Is it a known good one? Do you have access to another to check?

therest

As far as I know the ECU should be fine. I could try to get a hold of another one just to make sure.

Like I said my wiring is a little different and if the ECU isn't the problem then I might as well just try to wire the conversion like you did.

F22Master

Well even if you used 2 of the facory wires, it should still end up the same.

1 wire from pin A1 to #1 injector
1 wire from pin A3 to #2 injector
1 wire from pin A5 to #3 injector
1 wire from pin A7 to #4 injector
1 wire from pin A15 to the odd colored wire from the resistor box

No matter what route they take from point A to point B, as long as they are connected, it will work. Have you checked continuity on those 5 wires?

therest

I have and there is no voltage. I've checked the two existing injector wires from the harness and they don't have voltage. That made me think that my Main Relay might be bad BUT I do hear it click as I turn my key to the position just before cranking the engine.

F22Master

They wont have voltage. You are not checking for voltage. Continuity checks to make sure the wire is connected and not broken.

good video:

therest

I see what you mean now. I'll check for that tomorrow. That's really helpful. Thanks a lot man.

4drEF

A15 does not power up the resistor box.
The main relay provides this power and shares it with both the resistor box and the ECU.

When you first put the key in and turn to the position just before cranking, does your check engine light come on for about 3 seconds and go off?
If this -IS- happening then you have a break in your yellow/black wire or your main relay is shot.

No need to check any other wires until you get power on the yellow/black.

F22Master

Unless you bypassed all stock wiring and ran a wire directly from the resistor box to pin A15.

4drEF

What? A15 receives power.
It does not provide power.

F22Master

No, the power comes from the ECU, to the resistor box, then to each injector. The ECU then grounds each injector when it wants them to fire. That is how I have come to understand it, and I wired accordingly, and it works fine. My resistor box is wired directly to to pin A15, no relays or any other wires. Each injector is wired directly to the ECU at its corresponding pin.

4drEF

Well, I'm done trying to explain to you.
The schematic is clear as day.
If you really think the simple electronics trace in the ECU is sufficient in any sort of manner for substituting what a 15A rated thick wire from the main relay is - well, best of luck to you then.

therest

4drEF, im going to check if my CEL goes away as soon as I get home. If it does g away I think it will be my yello/black wire because I can hear my main relay click. If this isn't enough proof to prove my main relay is working please let me know. Thanks again to both of ya.

therest

So I just checked my CEL and it DOES stay on. I also checked with another Main Relay and it stayed the same.

therest

Ok, so I have gone out and checked for both voltage and continuity to all of my wires. Everything has continuity and voltage EXCEPT no voltage from the ECU (ground) to the injectors. My cousins and I were thinking that there might not even suppose to be any voltage coming from the ECU since the ECU acts as ground.

Other than that there's a possibility my resistor box is bad or of course my ECU.