NickH93

Hey all, still driving the same CRX I've been beating on for 4 years, having a new issue lately

Sometimes when I am driving, the engine cuts out for a split second, and the radio and accessory power also cuts out with it. It comes back immediately. It has a check light for a few seconds, and then disappears, just like it would if you've turned the key.

I've noticed too that sometimes an electric load will cause this to happen. If I turn on the AC, for example. Or press the brake. or turn on the headlight.

Electrical load doesn't always trigger it, and sometimes it just happens randomly.

I've already replaced the main relay within the last two years, and I resoldered this one just to make sure.

Any ideas?

NickH93

I see that with my whole comment of "turning the key" I could have pointed myself to the ignition switch, but would that manifest this way? That's not the common way I've heard that these fail, and last time I had it out, it looked okay, but then again, I can't remember when that was.

boibuddha

The ignition switches are not a common failure point on these cars, but having a big, heavy key chain hanging off of it can cause unnecessary wear.
The weight of all those keys puts forces on the ignition switch it was never designed to see and eventually cause it to fail.
Wiggle and/or tug on the keys to rule out the ignition switch.

It could also be a loose connection on the battery; clean up the battery posts and tighten all connections to rule this out.

NickH93

Sorry to have left in the dark but it happens

At any rate, my car just shut off and wouldn't come back on. The check engine light and ECU light was solid, and the pump wouldn't prime. Bypassed the main relay with some jumpers to get it home which worked, but then that night it shut off again even with the main relay bypassed.

This time it threw code 4, 8, 15, 16. So basically the ECU saw no ignition signals or fuel injectors/fuel pump when it died. The CEL has since went off.

Then I cranked the car and in the middle of cranking, it stopped cranking and the electronics dimmed for a second.

Also the main relay was buzzing. Basically clicking on and off really fast, which is why I thought to bypass it.

So now I'm thinking ECU ground, or some sort of ground connection somewhere.

NickH93

I cleaned up all my grounds and added a new ECU ground on top of the existing ones. When I tested the ECU ground with a meter, I'd get continuity but then random spikes of not having any.

Suffice to say, that did the trick it seems. Made it the 1.5 hours to work without any issues or main relay buzzing. Also my electronics no longer dim at low revs. Never noticed it until they stopped doing it.

Hope you all don't mind me posting even though I haven't gotten a ton of replies. But I hope me logging my train of though and successes may be helpful to someone out there struggling with a similar issue.

2x0

It is very useful, as someone who recently went through a buttload of electrical issues with my CRX

Glad you got it all sorted out.

NickH93

In true me fashion, it came back today. I hit a bump and out it went. ECU light and CEL both went solid, no priming, main relay buzzing. I moved one wire I had under the hood for a fan switch I added and it came back to life. But moving that wire when it was running wouldn't cause the car to die. May have just been a coincidence

Being that it is an MPFI swap also, I tried fiddling with all of my wiring when the car was running (ECU harness, sensors, etc) and nothing would recreate the symptoms.

So I chipped the ECU awhile back and thought maybe I ought to change the chip out, since I know all solid lights could be a sign of no ROM or bad ROM. Didn't do anything, but I did notice my ROM chip was blisteringly hot..

So I wonder if it heated up too much, stopped working, and then worked right when it cooled down.

Definitely abnormal. I wonder if the solder joints I made years ago are cracking and shorting stuff out. Otherwise I'm at a complete loss.

2x0

Definitely sounds like a bad solder joint, either in a relay or in the ECU. They can be temperature sensitive. And I don't believe anything in the ECU should get that hot, so I would start there.

NickH93

Sorry for so many updates

Leaving later today from work, the car would start, and run for 5 seconds, the tacho would fall to 0 and then shut off. Code 4, 8, 15. CKP sensor, TDC sensor, Ignition Output Signal

For the 5 seconds it would run, it ran like garbage.

Cut to it magically staying running normally, then I'm able to drive it home. The ROM chip has stopped getting hot, but at any rate, I reflowed all of the solder joints I made when chipping this ECU. No components appear to be burnt or anything. The solder joints looked faintly suspect but I don't know, they're great now at any rate.

Just again, running the car and moving my ECU harness, ground wires, MPFI wiring, and all of that, it wouldn't revert back to dying how it did on the road. I don't know if my main relay is on the fritz, or if the ECU is on it's way out.

Or. with all the sensor codes in the distributor, maybe that's going bad? I've fried 2 ignitors in the car's lifetime, but I don't know that it would cause any of these issues. Both times I've had those fail, the car just dies and never came back on.

4drEF

I'm going on the premise that all the grounds you replaced are fantastic and you prepped the bare metal for fantastic contact when you installed. (thermostat housing, chassis to tranny, radiator support to valve cover+head stud, battery to chassis).

How do the capacitors in the ECU look? These ECUs are getting to the ripe age where the capacitors start to swell up and fail. Since you were able to chip the ECU yourself, then you should have no problem replacing capacitors.