Unomi

Background info:

Engine stamp "B18C" and "9|3" block (1993 JDM B18C right?)





Chassis is 1997 Civic DX (had a D16Y7)

ECU is OBD1 P72



New Rywire Jumper Harness



Engine Harness Connectors





Car has trouble starting any time the wires are bumped. Now, the car won't start. I eliminated the shotty jumper harness for a Rywire OBD2a to OBD1 harness. Car started and eventually died. I tried to trace wires from the Engine Harness and it's not adding up from the manual or diagrams online. The wires from the engine harness connectors aren't following those diagrams. Your thoughts?

Unomi

I have a lot of views, but no replies. For those that might be following the thread, I:

Disconnected the connectors from the ECU
Removed the engine harness
Soldering all shady connections

It looks like I'll be moving a couple wires on the ECU connector side. More pics to come too...

Unomi

This is one of many connectors that are cut(for auto to manual transmission swap):



Engine Harness out:

Unomi

Updated synopsis:

Harness has been resoldered and it's back in the car. Car will turnover, but not start. It looks like there are a few pins that just don't go to correct place. The old jumper harness looked custom with speaker wire, hence the new Rywire harness. I'll be pulling the engine harness out again and tracing each pin to ensure it's ran correctly and not to some random spot that the old jumper harness had.

Unomi

Update:

I've found all the diagrams for the ECU and wire colors. I use Microsoft Paint to make it a tad easier.

OBD1 B18C ECU Connector "A":



OBD1 B18C ECU Connector "B":



OBD1 B18C ECU Connector "D":




Work has me slammed, so I'll be doing more research and simplifying when I get the chance. I hope some of this helps others out there.

Unomi

Update:

Removed ECU and jumper harness. I confirmed the custom jumper harness and Rywire harness have the same pinout. Then, I checked resistance/connectivity. Everything showed green.

Next, I,m pulling the engine harness to check its resistance/connectivity.

I'm still looking for any help...

Unomi

Found something:

First, I tested traced wires from the old and new jumper harness. Both are identical and the rywire passed resistance test.

Old vs Rywire Harness:



I opened the ECU. At first glance, the board looked fine. I took a closer look and I may have found my troubles. I didn't notice and exploded capacitors. However, there's discoloration and what looks like a melted substance.

ECU Board (Top view):



ECU Board (Bottom View):



ECU Board (dmg close-up):



Can anyone confirm?

Unomi

Waiting on PayPal to update funds. I'm buying a chipped/socketed OBD1 P72. The thread will probably snooze until the part comes in. Unfortunately, it takes a couple weeks to ship to Guam. :-/

Unomi

ECU is shipped and spent some downtime looking for a magnetic drain plug. I went with Blox:

http://www.bloxracing.com/bloxshop/i...product_id=345

Unomi

Update:

Received P28 chipped



...installed




So, engine turns over, but wont start. CEL 41 exists and I have a brand new O2 sensor. Any help on how to check this out?

Also, What would be the best way to ensure spark and fuel are making it to the chambers?

Unomi

Ok, I'm really at a stand still. I've found things that need to be replaced, but all the obvious is taken care of now. I have searched many times over and done plenty on my own to gain respect from the seasoned techs on the site. Can anyone please make a suggestion (sensible)?

Unomi

Took a pic of the external coil w/ ground removed:



Old wire (passed ohm test, but still wanted to redo it):



New wire and solder (still passed ohm test):



I need to redo the positive, but that will have to be tomorrow:

Unomi

Small update:

Went home, checked to see if the fuel pump was working. Placed key in "on" position and I can hear it apply pressure. I'll kept testing piece after piece til I find this hiccup.

VegaS10

I would remove the MSD setup and use OEM ignition parts.

Unomi

I thought of that, but those parts are hard to come by on the island. I haven't ruled it out though, even if I have to pay a little to ship it from the states.

I still search through endless threads here and came across a similar problem that turned out to be a spark problem. I'll be testing my plugs soon. I didn't have the time to get the socket to pull them.

Also, thanks for the input Vega. If I get impatient, I'll be going back to stock ignition coil.

Unomi

Installed the ground again and tried cranking. I didn't really expect it to crank since the original wiring passed the resistance test. I'll post once I test the plugs. In the meantime, did my first oil change to my motorcycle. It was a complete success and working great. At least I have some good news in the automotive category.

Unomi

Update:

I tested spark to the cylinder. All the plugs had built up carbon, which isn't too bad. However, cylinder three shows oil.



The car would still be able to sound like it crank, but it doesn't. Here's a clip of it turning over, but no combustion.

http://www.youtube.com/watch?v=JYYrQx4fvxI

I have a fuel pump and fuel pressure gauge coming in. Fuel delivery is the last thing. Then, I guess I can move on to more technical issues if they exist. Again, I'm still looking for tips, advice, etc. Please give your two cents.

Unomi

Update:

Today, I checked all the interior fuses. I did have to replace a couple, but none that related to the car not starting. I did manage to get a clip of audio verifying that the fuel pump is priming:

http://www.youtube.com/watch?v=z0e7XWpFoEM

Just for the record, I jumped the plug and received CEL 41:

http://www.youtube.com/watch?v=XFxiepwcpO4

Tomorrow, I'll be testing voltage on the fuel pump and injectors.

Unomi

Small delay:

I'm charging the battery today. It finally ran out of juice while troubleshooting the car. Tomorrow, I'll be testing voltage on the fuel pump and injectors.

Unomi

HUGE UPDATE!!!

Last night, the battery was charged to full. I put it back in and turned the key to "on." I was going to start testing the volts to the injectors when I heard the fuel pump ACTUALLY prime. It was a different sound and this time, fuel flowing. I proceeded to crank the car and it started, without any hesitation. It starts every time. The bad thing is I'm burning oil. As shown in the above spark plug pic, I more than likely have a bent valve or fried ring. At least I know what's going on now.

Synopsis:

Possible bad connections on the engine harness (resoldered)
Fried capacitor/resistors on P72 ECU (replaced with P28 chipped/socketed)
No fuel from fuel pump (recharged battery and reconnected the connector)

I also have no more CEL!

I will get a better clip to show perhaps smoke and better sound to hear the knock:

http://www.youtube.com/watch?v=Y9qoGLpG5ls

Unomi

I'm trying to price valves, retainers, springs, and perhaps a rebuilt kit. If anyone has some good places to name drop, please let me know. They have to ship to APO.

pleej

just like to say well done for not giving up

Unomi

Tyvm... I'm determined and still moving forward to for a stock rebuild. So, much more to come.

Unomi

Follow-up:

The car is still doing well, but I'm taking it easy. The fuel pump is in and the fuel pressure gauge.

Walbrough 255:


Pressure Gauge:
<need to take pic>

Run through 7,600 just to see where the motor stands:
http://www.youtube.com/watch?v=jAsyhCE1W8s

Unomi

Update...

Car is running fine and finally isolated most troubles to bad electrical lines throughout the engine harness. However, had a couple upgrades.

Walbro Racing Pump:

Top of the tank


Old vs New


B&M Pressure Gauge (42psi at idle)