twentyhurtz

I have the full shop manual for the 1990 honda accord ex on disc, but it is a scanned version and not a true .pdf where you can search. Also, i cannot find it in what i should be able to so I am looking here.
I am looking for the distributor wiring diagram for a 90' accord ex f22a.

The car just turns over, no spark. Put a new distributor on and the problem still exists. I used my meter to confirm that i do have + 12v to the coil (blue wire), but i do not have a signal from the ground wire to the coil. I'm assuming that the ground is switched or controlled by a sensor, either way i am not getting a ground to the coil. I have checked the harness ground which attaches to the thermostat and it is fine.

Once I can see a diagram I will be able to diagnose the problem, any help directing me to one will be greatly appreciated!

holmesnmanny

i believe the ecu sends the ground at the appropriate time...its not always grounded

twentyhurtz

I would agree that it is controlled via ecu, but i did not know if it ran to a sensor also. It is a larger gauge wire, so i thought maybe it is interrupted somewhere by a solidstate device first as opposed to the ecu doing the switching.

GhostAccord

The ground signal is controlled by the ignitor/ICM inside the distributor. If you have the real Honda shop manual you will find the distributor trouble shooting in the elcectrical section under ignition system.

This is a picture for an OBD1 CD Accord. The wiring layout is the same, not sure if the wire colours are 100%.



Ignitor/ICM test


Coil test

twentyhurtz

Kudo's Ghost Accord, yes i have the actual shop manual on disc, but whomever created the disc scanned the individual pages and put them on the disc as jpegs, and i cannot search for the section i need and for some reason cannot find it on the disc.

Thank you for providing the diagram, tomorrow I will use the information you have added to search for the issue. I think the problem is faulty wiring/connector outside the distributor, unless by coincidence both my old distributor and the brand new one out of the box both have an issue.

twentyhurtz

Update: Still having this problem with new information. I see that the ECU is throwing Code 15; after looking this up i see that the code is ignition output to the ECU. After doing a google search and finding what the code was, I also found that the Signal is from the Distributor back to the ECU and the signal should be 10v. I turned the key on and confirmed that i have the 10V signal making it back to the ECU (measured voltage at ECU input connector).

So, I have confirmed Fuel Pressure, o2, Compression, but still no spark. The current Distributor would not crank the car and neither would a brand new one out of the box. I have no output on the coil, but it seems that i have signal back to the ecu and i have power to the distributor, and the distributor housing is properly grounded. Any other idea's on why it might not be cranking?

twentyhurtz

Well I finally got the problem solved and it took a few hurdles to figure it out. I did everything from reflowing solder on the main relay, to mix matching parts, etc. I even pulled the ICM from my old dizzy and the new one and had them tested at autozone, they confirmed that both were bad, and the tester supposedly test 10 points or features/specifications of the ICM.
I found it odd the both ICM's failed all the same test except one. Either way I ordered a new one anyways for $110. When it came in, I made them test that one also, and guess what, it failed in exactly the same way as the two I have now. So my conclusion there was that they were really all good, that the machine they are using to test them is not properly testing them. They then told me that the manual for their tester doesn't actually say that it can test that particular ICM.

So, frustrated I finally found a flow chart/step by step procedure to test the distributor. The ICM provides the pulsating ground for the coil. One thing you can do if your 100% sure you do not have spark, is use a test light (one that that a bi-polar LED is best), attach the clamp end to your (+) terminal of the battery and the prong end to the (-) terminal on the coil with dist cap off of course, if you have constant 12v (+) to the (+) terminal of the coil, then when you crank the car, the LED in the tester should blink as the ICM is sending a pulsating ground to the coil.

If then there is still no output from the coil, then the coil is bad. Both my old and BNIB coil was bad, but of course the new coil been sitting in a box a few years and the company i bought it from is out of business (wonder why).

As Ghost Accord shows above, the spec for the primary and secondary coils. I did originally measure these and the secondary coil on the new ig coil was reading 7100 ohms. Being that it was supposed to be a high output coil, i did not think much about it being a lower value.

Being an electronics engineering major, i SHOULD have caught on to the problem and ashamed that i didn't think about it enough. The Primary to Secondary coil turns ratio has to be high enough to step up the voltage. It takes high voltage to Arc, that lower voltage which was output by the lower resistance secondary coil, was not high enough to create an arc.

Either way, now the beast runs.