This one is a stumper. Having a bizarre intermitant spark issue, both on ignition and while driving.

The problem first manifested itself about a month ago. I was driving in hot weather when my engine suddenly died. There was no sputter, just an instant lack of RPMs. After some troubleshooting it turns out the coil was out of spec. Easy, right? Hot weather failure. Replaced the coil on the side of the road, still no spark. Back to the part shop, bought a new main relay. No joy. Bought a new distributor (including ICM), distributor cap, rotor button. Got spark, all is well with the world.

About a month goes by. Tried to start one morning and the engine had trouble turning over. It would crank strong every time (sounded just like normal), but never turned over. After trying to crank three times I took the key all the way back to the off position, waited a bit, and then tried one last time. Engine turned over within a second, just like it should.

Same thing happened when attempting to leave work that afternoon. A day later it started perfectly several times, then had trouble again. After letting it rest a moment, taking the key back to off, and trying again, it starts perfectly.

Replaced the plug wires and plugs, still no joy. Took both the coil and distributor back to the part store, swapped them for new ones, problem still occurs at random.

While driving to work this morning I just happened to be glancing at the instrument panel when the tac' plummeted to zero like a stone. No power from the engine, but accessories continued to function like nothing had happened. Words were spoken. Got to the side of the road, took the key back to off, waited a moment, tried to start several times, and got it to turn over again.

All during this time I've occasionally noticed bizarre things happening on the instrument cluster. At random (very rarely) the speedometer will drop to zero, stay there for a moment, and then jump back to the current speed. The tachometer continues to report correctly when this happens, and the engine/accessories still have power. I've also caught the "door ajar" warning lights and "brake light warning" all kick on while driving, stay lit for a second, and then extinguish. The speedometer and tac' both continue to report properly.

My dad (who was a diesel mechanic for many years, and has owned Hondas for over twenty) and I are stumped. We're considering replacing the ignition switch next, thinking perhaps it's making intermittent contact and causing havoc, but honestly we're grasping at straws.

We've also listened for the fuel pump priming, and it does. We've checked battery voltage, and it's A-OK. We've checked voltage through the wiring harness to the distributor, and it's good. Timing is also also good. No fuses are blown.

It's difficult to catch in a failed state. By the time you get the hood up and a spark tester on, everything decides to work perfectly and you can't MAKE it fail to save your life.

As you can imagine, it's beginning to wear at my sanity. Any suggestions?

 

Welcome in,I'm with you on this one all pointers are the ignition switch,you have replaced most anything that would be eletrical or fuel related and the fact that you pull the key and let it reset does sound as if the ignition switch is bad,please let us know how it works out.

 

Well, this certainly wasn't helping things:



I swear the instrument cluster is brighter now (though that could be placebo.) So far it has started perfectly, but being an intermittent issue... only time will tell.

 

Well, that officially wasn't it. Had to crank four times this morning before the engine would start.

I. Am. Befuddled.

 

More mysteries.

Put the vehicle back in diagnostic mode, and got a code 14 on the D4 light. Never seen that code before on this vehicle.

Tried to crank last night and noticed the D4 light blinking until I took the key back to off and tried starting again.

This morning we tried cranking and have been unable to start the vehicle at all. There is no blinking D4 light this time. The coil is producing spark, but there is no spark at the plugs.

If I hadn't replaced the distributor twice in the last month I'd do it again.

At this point we are thinking either ECU or TCU. Wish there was a way to test them before simply throwing more parts at the problem.

 

Here you go.

 

Final update for those who have arrived here after searching for the solution to this issue:

Eventually we rigged up a custom LED diagnostic test box, connected to various points within the electrical system, and waited for the random failure. Turns out the replacement main relay was bad out of the box. Replaced it (again) and all was well with the world... for a few months. Then the transmission decided to shift into 2nd while doing 75Mph on the interstate. I gave up on tho old girl. She took me to nearly a quarter million miles on the odo, time to leave her to a well deserved rest.

 

Thanks for letting us know,I have had several parts go bad right out of the box.not unusual that is why I mention it to people from time to time.Sounds like you got your moneys worth .