1993 Honda civic starting problems
 

Hello all, I am having an electrical issue with my car and cant nail it down. I have a 93 with a replacement 1.6L engine. A few months ago it completely quit with me. The fuel pump side of the main relay would not engage. I found wires shorted inside the distributor that fixed the problem. 2 days ago it started a similar problem. when turning the key on the fuel pump side of the relay doesn't engage every time. if the relay pulls in, it will start and run fine. I can cut it off and the next time it may or may not start. When the relay does not click, I can touch the grn/yellow wires on the main relay connector and the relay will click but it still wont start. you can turn the key on and off until the fuel pump runs and it will start right up. it may take 1 time or it may take 10. the test light also slightly light up. when it starts properly I have no current on these wires but do have current on the wire going to fuel pump.The last time I could tap on the distributor and the wires inside would touch and cause it to cut off. I have tapped on it and pulled the wires. Not 100% sure I don't have a problem in there but hate to start throwing money at it. Any suggestions on what/where to check. thanks so much for any help.

First things first, before poking around disconnect both battery terminals from your battery, disconnect the negative lead first then the positive lead.

The first thing that comes to mind is your ignition key lock mechanism has become faulty, but that usually requires an expensive repair to replace the whole ignition key assembly, so I'll just tell you what I usually do to repair electrical faults in cars.

http://www.ebay.com.au/itm/92-93-94-...item3f31207692

Visually Check the earth lead going to your battery on both ends of the cable, if your battery isnt getting a good conduction to earth then nothing else will work. You can remove the bolt from the chassis and clean both sides with 1200 grit wet and dry, or emery board.

If that doesn't fix it then the Corrosion must be somewhere else, this is a classic sign of corrosion happening somewhere. To remove corrosion from connectors I usually just use WD40 (it has to be genuine WD40), spray a bit of it on there and plug the connector in and out a few times to clean the terminals.

I would check and spray the connectors going to your ignition switch, as is shown in the ebay link above.

If there is corrosion on the battery terminals that can also be a bad sign that your battery is about to cark it. I would pour hot water (from a boiled kettle) onto the battery terminals to melt away any corrosion.

This is what battery corrosion looks like:
http://i.imgur.com/atl4esS.jpg

To re-connect the battery safely without large sparks, I usually always connect the positive terminal first to the battery and THEN the negative terminal second. This order in which you reconnect a battery prevents large sparks from occuring. Disconnecting a battery from the car is the reverse order.

Always maintain positive to positive (positive to red) and negative to negative (negative to black). This is called polarity. Never reverse polarity on a car battery, ever.

I am sorry, I should have noted the cables have recently been cleaned and reinstalled with dielectric grease. I also checked the ground wire that runs from engine to the chassis. I also removed the back end of the ignition switch and checked for proper voltage. Everything there seems fine. I had a suggestion on a civic forum that it may be an issue with my ecu. I guess this may be possible since I suppose it controls the power going to the main relay. Something may have happened in it a few months ago when the wires inside the distributor shorted out. Does anyone know of a way to test the ecu other than swapping it out with a $300+ part? Thanks

Make sure you have a good engine to chassis ground. Most of the time they are connected from the valve cover to the car body and easily visible with the hood open. Clean the connections even if the wire is connected, if not that is probably your problem.

Take a DVM and check for bad connections from the battery to various points on the car, both positive and negative circuits. When-if you find any voltage reading above .10 Volts that will be the portion of the circuit where you have a marginally bad connection.

regards
Mech

Don't you just love intermittent electrical problems. ;)


Sound like a poor connection at the relay. Bad relay? Can you swap this relay with another? Can you open it to clean the contacts?

Voltage check can be some what misleading depending on how and when the check is done. Sometimes just the pressure of the probe can change the reading. Making the checks when the problem is occurring usually net better results. If removing the back took the switch contacts out of circuit the results may have changed.

Not a Honda guy, are you sure you don't have a separate relay for the fuel pump. Have you checked the fuel pump wiring? Some of the Honda guys will probably be by and give you some tips.


DeoxIT is a good contact cleaner.

Thanks for the responses so far. If it would just quit I think I would have a lot better chance of finding the problem. I have checked / cleaned all the major grounding points as well as the conecter going to the main relay. After doing a lot of research last night at work, these models have a problem with the soilder points inside the relay breaking and causing my type of issue. I plan to get it off as soon as I get up today and take it with me tonight and desoilder/resoilder all those points and see what that does. If anyone thinks of anything else let me know please bit it may be a day or 2 before I can do much with it. I hope to get this straightened out and then,since I found this great website, I'm going to start trying to increase my 32mpg I get on my 100 mile round trip daily drive! Thanks again

Nemo, according to the manual this main relay is the only one for the pump. I can manually engage the points on the fuel pump relay side and the pump gets proper voltage and runs fine but it still won't start until it gets the proper ground or power from the ecm or sensor in distributor that tells it the engine is turning. It acts like it is either a bad ground, a bad soilder in relay as mentioned, or the ecu going bad. If my resoildering don't help I may try to add an additional ground in the circuit and see what happens. Thanks again, Mike

:D

If only you can choose the where and when. Been trouble shooting electro/mechanical circuits for thirty years. Have no Idea how many times I've wished for just that. Every year it gets tougher, smaller connectors and signals that can't be checked in the field, etc.


Be sure to post the answer when you find it. You will find it. Persistence pays off

In the CRX world (those only go up to 1991, but should be similar to our 93 in many ways) the main relay is a very frequent suspect for any starting problems. After a couple of decades, the solder joints inside the relay can crack and get intermittent. It is often recommended for owners with problems like yours to take the main relay out, remove the plastic cover, and re-flow the solder or even completely re-solder the connections.

I wound up buying a new relay, myself. In my case, it didn't solve the very intermittent problem, but it has worked for a number of people.

-soD

SOD: that's what I have spent my night at work doing so far. I removed the relay before I left home and have been sitting here removing then replacing the solder on each point. I wish I would have brought my meter with me because I found 2 spots that I would have loved to have checked before redoing it. Maybe I will have time to stick it back in tomorrow and report back.

To clarify is this a OBD1 or OBD0 motor? The 1.6 came in the EX model. Do you have a EX? Curious to find the problem.

Main relay controls both spark and fuel, if you don't have sparks either while cranking the engine than it is most likely the main relay contacts are bad, it is common on Hondas.

93 Honda
 

My 93 Civic has the same problems , so did the relay fix the problem?