I have a 90 1.5L civic LX. It started sputtering and stalling at stop lights. Then became a no start. It had spark and fuel. But would not hit at all.
This was in may. mk378 and ronj gave good suggestions and I was able to discover
that jumping the timing test port did not make a difference in the timing.
I sent the ECU in to be checked, and they say that it is working fine.

My question: If the ECU is sending the signal to change the timing, what
component is getting that signal? is it in the distributor?

Thanks Dave

 

If you have spark and fuel, then you should check whether the timing belt has skipped a couple of teeth, if you have not already done so.

 

Yes check the cam timing. I don't know if jumping the test connector is supposed to affect the timing if the engine is not starting, it may only do it when running.

Also check for any ECU codes, if a sensor in the distributor is bad it may set a code. Codes are read simply by turning the key on and watching the LED built into the ECU.

 

This problem slowly got worst over time, like a component slowly going bad.
I have checked the timing, fuel and many other points that you guys have suggested.
I thank you once again, also no trouble codes.
I have also checked most of the sensors, etc under the hood with the help of a factory manual. everything checks out good.

The last thing I did, was to pull the plugs, jumper the timing test connector, and try to check timing just cranking the engine over. I couldn't see squat. Put it all back together
and the car started. At this time I checked the timing, with it running, and found that it made no difference in the timing if the connector was jumped or not. The car idled for about an hour then died. a couple of days later it started again, and I was able to repeat the test with the same result, timing did not change, and car died after an hour of idle.

I sent the ECU in to be tested, and they say it works fine.
I will check the test connector wires to the ecu.
but if the ecu is getting signal to change the timing, what is the output signal, and where does it go?

 

Could be the fuel pump, main relay, coil, or igniter quits after a while. You need to check the spark and fuel carefully when it is not starting.

Every spark pulse goes thru the ECU. The ECU reads the sensors in the distributor to track the rotation of the engine, delays or advances them, and at what should be the proper time, drives a pulse out to the igniter unit in the distributor. The igniter unit amplifies the pulse from the ECU and drives the coil. It does not do any timing.