I'm highly suspecting something is causing the main relay on my EM1 to die. Well, I'm not 100% sure its dead, but it sure seems like it. Anyway, I'll try explain how I got to this point. For reference, my car has its original B16A2, the standard OBD2B ECU, and its relatively OEM. No major modifications.

Over 2 weeks ago, I drove my car out to get some fresh fuel. Prior to this, it pretty much sat on my driveway doing nothing. The occasional startup to make sure the battery doesn't die. After getting some fuel, I drove home and parked the car in the same spot its always in. I let it idle a little while before turning it off completely. Couple of days later, I needed to use the car. Turned the key and nothing. I'm scratching my head because I didn't change anything and the car was driving just days ago. Couldn't figure it out and I had no daylight, so I left the troubleshooting for another day.

When I got the chance, I checked for fuel first. My car is from the UK, so it has a factory immobiliser unlike the USDM EM1. Its deactivating like it should and its letting the fuel pump turn on. Next I checked if fuel was getting up to the filter. Cracked the banjo bolt loose and cranked the car over. Fuel was spraying out, so good sign. Next I checked if I was getting spark. Pulled the spark plug from cylinder 1. Grounded it off the engine block and had my mom crank the car. I was getting spark. Weak spark, but spark nonetheless.

Confused, I had a friend come over the next day with his multimeter. He checked if the injectors were getting signal. They were. He wanted to be thorough, so we checked spark at cylinder 1 again. No spark this time, which really threw me off. Because of that, we checked if the ECU was getting power and sending signal to the distributor. It was all good. We even opened up the ECU to check for possible damage. Looked fine. Using the meter, we checked for continuity from the ECU to the distributor, and then continuity from the distributor plug to each connector going to the ignition coil and igniter.

We thought it must be the igniter, so I borrowed a working distributor from another friend. Installed that into my car and its the same no start situation. Getting annoyed and desperate, I tried an old relay I had in storage, after reading someone's message on Instagram. It was causing the car to misfire in the past, but it would let the car run at least. Unplugged the main relay and plugged the old one in. I just let it dangle there too because I didn't have any confidence thinking it'll solve the problem.

First crank, nothing. Second crank while pumping the accelerator, boom. The car sprang into life. It was running like normal. No weird sounds. Smelled a bit rich, but I think thats from all the cranking. I got excited and there was a car meet on today, so I knocked the car off to clean it up. I got all my tools out. Mounted the ECU back into place. Tightened the negative terminal on the battery. While I was doing all this, my friend was at my house, happy for me. We're thinking we can go to the car meet now.

I tried starting the car again and NOTHING. Its dead again. The one thing I noticed is the car is cranking over faster than before. Anyway, because the main relay was changed that caused the car to start, we checked that first. It was really hot to the touch. Is that normal? My first thought is maybe when I was bolting the ECU back in place, maybe it did something, so I unbolted it from the car. Cranked it while moving the ECU around. Nothing. Did the same with the main relay because it could be a slightly broken wire within the harness. Same deal. The car won't start.

I'm lost right now. I'm getting no check engine light. I tried the original main relay. I can hear the relay clicking. Something caused the first relay to fail and now it has done the same to the second relay. Thats what I'm thinking. I will say, I have a killswitch spliced into the green/yellow wire on the main relay. Its crimped and I used heat shrink as well. Would that cause the relay to fail? I think its unlikely since the car has been running with the killswitch installed for a good amount of time. I only had the second relay in the car for like 5 minutes max before turning the car off.



I live in Ireland, so its been really damp until recently when the sun started shining again. I had the car under a car cover, which caused a lot of condensation in the engine bay. Theres a lot of white oxidation on the aluminium. Is it possible its a bad ground?

 

My suspicion would be some kind of rodent damage. Have you inspected the wiring harness for any damage?

 

All the wiring inside the bay looks fine. The harness is laid the same way its been for last 3 years of ownership. I checked the dash side and nothing is melting or obviously broken.

 

After looking at a few threads, on multiple forums, and looking at diagrams for the main relay, I've come to the thought that it can't possibly be the main relay causing my car to not start. I'm new to B series stuff, so forgive me for thinking the main relay is related to spark issues.

I had a friend bring my relay back home with him. He bench tested it, using a Honda manual I provided him. It checked out and theres nothing wrong with it. This leads me to believe that when the car started, when I changed relays, was pure coincidence. So now its back to the drawing board. I know for sure I'm not getting spark consistently, so its the distributor, plug leads, plugs, and other associated wiring. Am I correct? I did clean the thermostat housing ground a bit with some 500 grit sandpaper. Maybe I didn't clean it enough.

Any suggestions on what to look for? I have the 8 pin distributor plug and it looks pretty clean. None of the pins are bent or show signs of corrosion. I'm using OEM distributor parts, except the coil. The coil is a NGK replacement. Its also a Type R distributor on my B16A2, but its the same distributor I've used for the past 3 years. Unlikely a compatibility issue I would think. Leads and plugs are high quality NGK parts too and they look fine, as in normal expected wear.

I ordered new OEM coil and igniter, so those will be with me soon.

 

I was fiddling with the car today. Changed my plug leads from NGK to OEM Honda ones, with no success. Took the distributor cap off and picked the white buildup off with a flathead. Still not starting.

For curiosity sake, I sat in the car, cranking it multiple times. It started maybe after 15 tries? I didn't touch any of the distributor wiring or anything at the ECU, so I don't think its a broken wire inside either of the looms. I don't have the coil or igniter yet, so I can't confirm those are the culprits.

Someone suggested I check my ignition switch and clean the contacts on the inside. Whats the correlation between that and the car not getting spark? Well the car does get spark, but inconsistently. When the car WAS running, it was idling perfectly. 800RPM once warm and pressing the throttle, there was no breakup at all.

Heres a video of me trying to start the car again, not long after when the car was running earlier in the day.

 

Weak to no spark seems like a bad coil in the dizzy. I think once you have your new coil your issues will be sorted, but won't know until you have it. FSM has the test for it. I think it's just a resistance measurement test but it's been awhile, I don't remember exactly.

 

Car is fixed. Its a European specific thing, since the American and Japanese market didn't have it. The immobiliser unit that surrounds the key seems to have gone bad. Swapped to a spare I had and car fired right up.

Normally on Euro spec clocks, theres a green key indicator, but since I'm running USDM EM1 clocks, I can't see if immobiliser was deactivating properly. In case people encounter same issue as me, immobiliser kills both spark and fuel.

 

Thank you for the response. Glad to hear that you are good to go.