techsupport

I have a 93 Honda Civic and it has never had a starting problem. It has always fired up every time I turn the keys. That all changed on me last Friday, The car sat in the rain for 2 days and was not started. I got in it, turned the key and noticed a little hesitation. As I was driving, I noticed I was low on gas. When I got to my destination my car would not start, I was parked upward on a hill, and thought that the angle and low fuel my be acting as if the car was out of gas. I coasted down the hill to level ground and it started right up. A few miles down the road, I stopped and fueled it up. My car wouldn't start and was towed home. I did some trouble shooting and at fist noticed I was getting no spark. I check the coil and found that power was getting to the coil but when I cranked the engine, no power was coming out of the coil. Since I pretty much demolished the dust cover and rotor, to get to the coil I just weft ahead and bout bought a new dizzy. I installed the distributor and realized that I was still getting no spark. I removed the air hose, opened the throttle body and smelt no gas. Got back in the car and when the key turned there was no clicking sound coming from the main relay. I checked all the fuses in the dash and by the firewall under the hood and they are all good, I tried to get and ecu today but there were none available locally. I got a new relay and cleaned up the ecu with electrical parts cleaner. Now the relay clicks twice when I turn the key. The spark plugs are firing and the engine will run if I spay ether into the throttle body. I do not hear the fuel pump running. There is a winy humming sound that is coming from somewhere in the intake area, I have never heard this sound before. I cracked open the fuel line from the gas filter, turned the key and got no gas to come out. I am stumped, any ideas before I buy and replace a fuel pump?

x.l.r.8

I only have general car knowledge but injection fuel pumps do not like to be run dry, they rely on fuel going through them to keep them cool. that said first routes for trouble shooting a car that has run dry that previously had no issues is the fuel filter, followed by the pre filter, on your way to looking at that lot I would check voltage at the pump, remember you only see voltage for a few seconds while it primes.

x.l.r.8

I haven't looked at the schematics but if the ecu is not seeing fuel pressure or if it is seeing an overload in voltage from a shorted out fuel pump would it still allow for a spark? I would take the inlet of the fuel filter off and start your test from there.

techsupport

Thank you for the great advice. It might be a few days before I am gonna be able to start back on it. I will keep you posted on my results and continue to look for more community replies and tips.

Former User

Run power and ground wires directly from the battery to the fuel pump to see whether it runs. If not, replace it.

techsupport

I ran a wire wire directly to the fuel pump and the car started right up. This was originally going to be just for trouble shooting but I have added a switch and fuse to the wire and have been driving it this way for a few weeks. I turn the switch on before I start it and then off when I shut it down. This has worked until very recently. My battery keeps dying on me and I am getting an error code of 41. The other night the battery light flickered at low RPM. I was able to make it home about an hour drive at night before it died on me. The car ran very sluggish and the windshield wipers moved slow. I had to really put my foot on the gas pedal to get it to move from a dead stop. I jumped the battery with another car and while my car was hooked up to the other cars battery and running the 41 CEL went away. The battery light hasn't come back on again since it flickered at low RPM's the other night. I have it on a charger right now and just want to make it to work and back so I can try and figure out what the problem is.
I want to remove the hot wire to my fuel pump and go back through the troubleshooting steps. But right now that wire is needed to make the car run.

I forgot to mention that this all started after it had been raining for awhile. I suspect that the ecu is getting moisture. I have recently replaced the ECU with one that I bought on Ebay. That is when the code 41 started to show up. I put in the previous ecu but the car will not even start with that one. The hood is raised and the floor by the ecu is wet. I think I just answered my problem here in the last few sentences.


Eric

x.l.r.8

I suspect the main fuel pump relay, you can bypass, just do a search on the forum. but I suspect with your hot wire you are back feeding the ignition and living on borrowed time and possibly heading for ECU burnout.
41 is heated o2 sensor. your probably running way to rich with your fuel pump on, Im guessing thats your error code.

techsupport

This is where I left off a couple of hours ago. I plugged everything back in and did some more tests:

Fuses Test: Hood fuse 31 and dash fuse 24 are good. Tested all fuses with OHM meter and test light. They all have power and fuses have continuity. Fuse 24 was tested with the key on.

G101 Test: Cleaned and tightened the G101 ground wire attached to the thermostat housing.

Main Relay Test: Unplugged the main relay, resoldered it, and checked voltage on terminal connectors 1 and 5 and they have power. I jumped terminal 7 wire to both terminal 1 and 5 the fuel pump turns on. Terminal 2 wire has ground to the body, tested mith OHM meter.

ECU Test: Grounded ECU harness wire A7 and A8 and the fuel pump comes on.

To Do List:

Plug in the main relay but unplug ECU connectors A and B. Turn the key to ON(II) and individually measure voltage to body ground at ECU terminals A25, B1, A7, and A8.
Write down voltage (if any)
1) Turn key off.
2) Reconnect main relay to its plug.
3) Unplug ECU connectors A and B (or all ECU connectors) from the ECU.
Check the ECU harness while the harness is still connected to the ECU (check pin B1 yellow/black) and make sure it's ground,Check the harness one at a time (pins A23, A24, A25) All should have ground. Write down Ohms reading:
Check ECU pins A26 and B2 have continuity to body ground, then:
1) Reconnect the main relay and ECU connectors
2) Unplug the MAP sensor connector
3) Turn the key to ON(II)
4) Measure voltage to body ground (thermostat housing) at the Yel/Red wire terminal of the MAP sensor connector. Should be 5v
5) Measure voltage to body ground (thermostat housing) at the Wht wire terminal of the MAP sensor connector.

I will post my findings when I am all done.

techsupport

After doing some tests the issues that I have come up with are: B1 ECU pin harness has a weak ground. Its a brown wire that I am going to determine where it connects to and fix. Map sensor Yel/Red wire is only getting 3 V.

techsupport

What relief, Thanks to everyones help I got it back together and running without hot wiring the fuel pump. It was a bad ground to the ECU.