JimBlake and TexasHonda got your answer down pat...
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As you're checking, look at the plugs. I've heard where the pins of the connectors can either get bent or pushed back so they don't make good contact when plugged together.

 

Ok guys since I wrote last time I found out that this engine had a cracked # 1 Cyl. So I have changed the engine that came with a distributor, intake head, and block all togther from a salvage yard. It has 100k on it. I started the car thinking that all plroblems with the check engine light will be gone. But NO WAY. The CEL is still on and starts shaking after 3200 RPM ( code #4). It runs great @ idle. So this leads me to conclude that the only possible cause is the wiring to the distributor just like TaxasHonda suggested. I am going to be checking that tommorow. Does anyone know if the wire is bad do you have to change the whole engine wire harness or can you just change that one? Any help would be appreciated. Has anyone ever exprienced this kind of problem?

 

You can replace the bad wire.

TexasHonda and Jim Blake are correct with checking the resistance through the wires. At the distributor you check the resistance between 2 (blu/grn) and 6(blu/yel) on connector C124.

Plug C124 back in and unpug the 14 wire connector near the engine bay fuse box (there are two large connectors there, so find your wire colors) and measure the resitance on those two wire colors at the connector going to the distributor. Finally measure the resistance between pin B15 and B16 at the ECU.

All the resistance readings should be the same. If you find a change, you will have isolated the wiring problem. Also make sure the pins and connectors are clean, pins are straight, and make sure they are making good contact.

 

If you've verified the resistance at 700-1300 ohms at the distributor connector, step backwards as JimBlake suggests. Somewhere there's a wire fault or pin fault.

It may be tricky to find if its a wire fault. It may be easier to just bypass the entire wire by splicing a new wire near each connector.

regards

 

Ok guys I am getting some progress here. I checked at the distributor and it was 840. Then I checked @ the 14 wire plug by the fuse box and it was 840. Then I checked @ the ECU and it was lower @ 640. There are three plugs on the ecu and I pulled the middle one out (16 wire) and seen the blue/yellow and blue/green wire then tested it. What do you guys think that should bbe the cause the wire between ECU and 14 wire plug? There was another unit there next to the ecu it had 2 plugs on it which the the same blu/yel & blu/gre wires on on it. What is that unit? Thanks so much guys for all the help.

 

The second unit is most likely the trans. control unit (TCU).

The 640 ohm reading is outside of the range in the 95 shop manual (700 - 1300 ohms). There must be a short in the wire.

There is one last electrical test in the shop manual. Test the blu/grn wire to body ground for continuity at the ECU connector. That circuit should be open. If that wire is gounded, then you need to repair that wire.

The wire feeds into the cabin through a grommet under the engine bay fuse box as part of the main wire harness from the 14 pin connector. I don't know the best way to feed the new wire in, so someone will have to give you more detailed instructions.

Good Luck.

 

I would be sure the VOM was zero'd. A change of 200 ohms is suspicious and difficult to account for. It could indicate a cross-connection to another wire. Try to isolate the wire at fault as follows.

W/ the connector to ECU disconnected, separately ground the two wires (blu/grn & blu/yel) at the 14 wire plug at the fuse box. Now measure resistance from ground to each socketat the ECU connector. They should show very close to zero resistance. A wiring fault likely would be an open circuit on one wire. A short to another wire would probably show as decreased resistance, but not a dead short.

Similarly, remove the jumpers to ground at the fuse box and check the ECU connector pins resistance to ground. Both wires should show open. Any reduced resistance would indicate a wiring fault (short to ground or another wire) in the harness.

Above should allow you to isolate which wire is causing the problem.

Examine the connections (both ends) very closely for and damaged male pins or female sockets.

good luck

 

Ok guys I made a mistake. My meter was acting up and I got wrong measurment @ the ECU.

So here is the measurements. 862 @ Distributor, 862 @ 14 plug connector by the fuse box, & 861/862 @ the ECU connector. So it all checked out. I am going to try to do that continuity to groung but I don't yet understand how that works. This is getting really technical for me. I was thinking about giving up but I will continue because I am in too deep. No point of quiting now.
The shop manual I downloaded from Hondahookup. What page is this information on about continuity to ground?

Yan

 

Could the ECU/ECM be bad?