Hey guys, as some of you may know, I've been struggling to get my b16a SiR II running in my CR-X. I've checked my wiring over and over to figure out why all 3 of the ecu's I've tried give me a code 8 CEL, TDC sensor. Bottom line, my engine won't start because the injectors don't get the signal from the ecu to ground out individually when it's time to spray. (I've confirmed that they all spray with 12 volts ran to them, and they all are getting proper voltage from the main relay). When I try getting them to spray manually while cranking, there is combustion in the cylinders, so I know they work.

I have narrowed the problem down to something is preventing the ECU from completing the circuit for the injectors, but I've tried 3 good ecus, same results. I checked voltage on each injector pins on the ecu while cranking. Injector 1, 0.1 volts, Injector 2, 0.1 volts, Injector 3, 12.0 volts, Injector 4, 12.0 volts.

Now, does this make sense, 12 volts run from the main relay (I tested it too, works fine) to the injectors individually. then the color-specific wires run to the ecu, and it's the ecu's job to ground them at specific times when they are supposed to spray. If there is 12 volts coming from the ecu at the specific pin, that would not complete a circuit, so that injector with 12 volts on both ends is not supposed to spray. I haven't confirmed this, but based on logical reasoning, I'm assuming this is how injection works.

Would the TDC sensor prevent this from happening? I know some other non-Honda cars won't start with a problem with the TDC, how about Hondas though? I pulled the dizzy off, checked resistance on both TDC sensors and CKP sensors, both pulling 360-380 ohms (and based on my Helms manual 350-550 is within spec). I checked for continuity between the ecu and the harness dizzy clip. The inside of this dizzy looks immaculate, like brand-new internals. Externally, the cap is not new, but fully functional. Unfortunately I don't own an ocilloscope, so I can't view the waveform the sensor gives.

Based on logical reasoning, this is what I think is happening. When the car is cranking, the ECU is looking for the signal from the TDC/CKP sensors to know when to spray the injectors. It's not receiving a proper signal, or its not getting a signal at all, so the ECU doesn't know when to spray so it doesn't spray at all.

Any thoughts? I've spent about a month and a half trying to track this problem down. I've spent a lot of money on diagnostic tools, supplies, fuel related items, tore down the head, intake, you name it. Mechanically the engine is sound, this is definitely an electrical problem. My compression is 210,200,190,190.

I have another thread here when I thought it was related to bad fuel here:
https://honda-tech.com/zerothread?id=850093

If anybody can confirm my theory, I'd much appreciate it, so I'd feel better dropping $ for a new dizzy.

 

anybody?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kur0ryu &raquo;</TD></TR><TR><TD CLASS="quote">anybody?</TD></TR></TABLE>
Does it have spark? If the ECU doesn't get all the inputs it expects from the ignition system, it wont energize the injectors.

 

there's spark. when cranking I put 12volts from the battery to the injector directly, combustion happens in the cylinder. I also pulled all 4 plugs out, cranked it, and saw sparks on all plugs when attached to the wires.

So, would the TDC sensor specifically prevent the ECU from signaling the injectors? Thats what I'm trying to find out. I've searched on people with TDC sensor CELs, and they all seem to have problems idling, reving, but I havent found a thread where they can't start because of it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kur0ryu &raquo;</TD></TR><TR><TD CLASS="quote">there's spark. when cranking and I put 12volts from the battery to the injector directly, combustion happens in the cylinder. I also pulled all 4 plugs out, cranked it, and saw sparks on all plugs when attached to the wires.</TD></TR></TABLE>
So it will only run if you supply voltage to the injectors, huh? They should have voltage all the time with the key on. Does the fuel pump run without the jumper?

 

yup, fuel pump runs without jumper, I did a full test on the main relay too, it's fine. Injectors are getting 12 volts from the main relay with key on, but the ecu is not completing the circuit. I'm thinking it's because it's not getting proper TDC/CKP signals, because wiring is good all the way around, even the wires from the ecu to the TDC/CKP sensors.

 

you didnt mention your ecu ground, kinda obvious, you prolly did check it. and yes, without CKP signal to the ecu, no injector pulse.

 

which ground should I check on the ecu? is there a specific one related to CKP/TDC? Also, CEL #8 is commonly referred to as TDC sensor, but I've seen some CEL lists that list both TDC and CKP on #8. Thanks for the insight, I'm so close to getting it running I can taste it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kur0ryu &raquo;</TD></TR><TR><TD CLASS="quote">

So, would the TDC sensor specifically prevent the ECU from signaling the injectors? Thats what I'm trying to find out. </TD></TR></TABLE>
I know the #1 cylinder possition sensor is needed for injector timing, but i'm not sure about the TDC sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
I know the #1 cylinder possition sensor is needed for injector timing, but i'm not sure about the TDC sensor.</TD></TR></TABLE>

CYP is a 9 though, and I've never gotten that code...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdm wannabe &raquo;</TD></TR><TR><TD CLASS="quote">try a known good distributor, or try your distributor on another car</TD></TR></TABLE>

I don't know anybody with a del sol vtec or a 92-95 gsr, or that would be the first thing I'd do.

 

well, I ordered a new dizzy, should arrive on tuesday, I'll keep you guys posted...

 

spark plug gap,if not,need distributor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H22AEG &raquo;</TD></TR><TR><TD CLASS="quote">spark plug gap,if not,need distributor</TD></TR></TABLE>

please read my previous posts, I've been getting spark all along.

 

Ok, here's an update. I got the new dizzy, hooked it up, and one wierd thing was that the orange and the white wires on the dizzy side clip were swapped, compared to my original dizzy. I tried starting it with them the way they were, then I tried switching the two on the harness so the colors match, same results. I was doing this on my lunch break so I didn't have much time to fully troubleshoot, but it wouldn't start with carb-cleaner, or when I tried to run 12volts to the injectors. So... maybe something as far as spark has changed, but I haven't checked it yet. I am still pulling a code 8 after cranking for 10-15 seconds. Any thoughts before I go back to try after work?