Hello,

I've been stuck with my project for a month now.
I cannot figure out why my injectors won't open.

My project is a OBD0 Honda Civic CRX with a B18C4 (obd2) engine swap.
I'm using the OBD2 dizzy and OBD2 injectors, without the resistorbox and the 5 remaining wires soldered together.
Also using a conversion harness from OBD0-OBD1 and a P28 ECU with B18 maps burned on the chip.

What I know so far is that the injectors get 12 volt to them, but it seems like they get no pulse to open.
The injectors are not stuck they are fully fuctional cause when the car is in "limp mode" (with my broken Ostrich emulator attached to the ECU) all 4 the injector will open at the same time at every top dead center.

I also used 2 different dizzy's, both should be working according to previous owners of both the dizzy's.

Any information/help/reactions things I could try, would be greatly appreciated.
Excuse me for my bad english but I'm from Holland so my native language isn't English.

Thanks in advance,
Dave M.

 

have you checked engine trouble codes at all?

 

Your English is better than a lot of people's on this forum!

Your 12V is a good sign.
The other half of the circuit is the ground.
This starts at the distributor where a signal is sent to the ECU.
The ECU then fires off a ground pulse to the injector.

Best "guess" is that your distributor wiring is wrong.

 

Thanks for the compliment about my English.

I have not checked codes, cause I thought it had to run a minute before I would get codes.
I will check that tomorrow. Hopefully it will point me to something wrong, atleast I can fix it then.

I've tried 2 distributors, I've checked the wires maybe 10 times. And I don't see a problem with it.

I looked up the obd2 colors and the obd0 and matched them up. I referred to a couple of sites for the colors, even a schematic from a conversion harness.

But if someone could list me the colors obd0 to obd2 once more, then I will check them once again.

 

Maybe someone can tell me how I can measure if the distributor is giving a pulse to the ECU ? Volt/Ohm/Continuity ?
Then I can rule out a few things.

 

if you turn the power on and let the ecu run its self test there are some things it checks right away as they relate to the engine running at all, those can be checked.
as far as checking a pulse, i would test continuity first. get your manual out and get the pinouts at the ecu for each wire on the distributor and make sure you have good connections.

 

Those continiuty tests I already did, nothing weird comes up.
Checked every sensor and important wire to the engine bay.

So thats why I want to measure the sensors in the distributor, so I can either rule it out or that I know its the cause of my headaches

So does anyone know how I can measure those sensors, if they are in good working condition ?

 

I will answer your question with a question...............

If it's OBD2, then why are you using an OBD0-OBD1 conversion harness?

 

Because obd2 and obd1 distributors are the same internally the only difference being the plug....

 

I'm using an OBD0-OBD1 harness cause the engine loom including the plug to the ECU is OBD0, and the ECU I'm using is the P28 which is OBD1.

Only the distributor and the injectors are OBD2, and those I rewired.

 

Injectors actually are not OBD specific, they're either peak and hold and require a resistor box, or saturated and don't require one.

Have you measured the impedance of the injectors?

 

They have OBD2 style plugs, and the original engine loom that was on the engine did not have a resistor box. So I assume that since I removed my resistorbox it should be just fine.

 

I just checked for engine trouble codes. I have a xenocron conversion harness, it uses 2 wires that you can hook up to a switch to check for codes. When I flip the switch (with key on position 2) MIL light turns on and stays on.
I don't know if that is normal for when you are using an conversion harness or not ?

 

With the key on position 2 and the "service connector" connected MIL light is on... so I started to unplug a few sensors, I noticed that MIL light goes off when I either unplug the ECT sensor or the IAT sensor, it gives the normal trouble code for ECT or the IAT sensor then instead of the MIL light staying on the entire time.

I can undo any other connector or sensor in the engine bay but the MIL light stays on when the service connector is connected. Only when I unplug either the ECT or IAT sensor the MIL light will blink instead of being on the entire time.

Maybe I found something ?

 

if the vehicle is not throwing any codes, and you flip the switch...the light on the dash will be solid on. This means the computer isnt registering any problems that would cause it to throw a check engine light.

 

you should be able to run a p28 with ur motor but my question is what kinda tune are u on? because u need to have a b series obd2 tune for it to work. as far as i understand thats the only reason i can see this not working other than a problem with the ground side of ur injectors...

 

Thanks for the update on the service connector. So its only called a "Solid Cell" when the service connector is NOT connected and the MIL light stays on ?


I'm using an P28 ECU with a P30 bin (launchcontrol and everything) with P72 GSR Maps copied into the fields.
So I thought that was the right way to go, for a base map then I mean.

 

Today I hooked up the test wiring harness of Honda. it was the original OBD0 test wiring harness, so I hooked it up BEFORE the OBD1 conversion harness.
So all following pinout numbers are the OBD0 pinout numbers.
I measured all voltages. Nothing really weird came up. These are the ones that were different:


B14 instead of 3.5 V --> +- 4.5 V (don't think that one really matters). dynamo switch.
B20 instead of 5.0 V --> 0 V , service connector, but I think this is bypassed in the OBD1 conversion harness.
C5 instead of +- 0.96 V --> 3.03 V , TA/IAT sensor, don't know if there is a difference between OBD0 and OBD2 engines with the value of this sensor ??
C10 instead of 12 V --> 0 V , brake pedal something, don't think that would matter but I will be checked that one later on the OBD1 harness where it goes.

I measured Ohm's on the CYL TDC and CK sensor, these are all within specs when ignition is on position 0 (ignition off). When key is on position 2 some of the values are higher Ohm's then the specs, but I assume I have to measure with the key in off position.

Also I went through the flowchart for the injectors and this is what came out:
No voltage between the 2 wires of every injector clip. I did have 12 volt coming to 1 of the wires of the clip (namely the ones that are coming from the resistorboxwire). Then I had to measure between the pinouts A2 or A18 and A1 A3 A5 A7, and I did measure voltage between those, so the flowchart result was that I had to get a new ECU

But I know the ECU is good, cause I drive with it every day in my Del Sol.

 

I fixed the problem, the problem was that I assumed a wiring diagram that I was given by a company here in Holland was good, while it had 1 fault in it. Namely that on OBD0 the orange color to the distributor would be the CKP but instead this is the CYP so I mixed those 2 sensors up cause of a wrong diagram
But I got it running now, so I'm still happy.