I have a 1991 Civic Dx Hatch-back. When I start the car for the first time in the day it starts right up. When I come back to it in about 5 minutes it keeps cranking but does not start. What could the problem possibly be.



Another thing my a/c doesn't work. Would the a/c compressor still click on if the freon were to be low? When I press the a/c button I can feel a little load on the car but not the compressor clicking. ????

 

When it will not start, turn the key on but do not crank. The check engine light should come on for 2 seconds and then go out. Also during that time the fuel pump under the back seat will run. If those things don't happen it is probably your main relay.

I think when the refrigerant has leaked out, the radiator/condenser fans will come on when you press the A/C button but the compressor won't engage. This happens when it is almost all gone, not just a little "low." See if the fans are running and the compressor turning (specifically the plate on the front of the pulley with flat springs, the pulley itself turns all the time with the engine running) when you have the A/C on.

 

If your AC system is low on freon the compressor won't start, thats simply a safety device, compressors must have refrigerant in order to operate without burning out.

 

I checked for those things: the yellow check engine light comes on for 2 seconds and goes out but I didn't really hear the fuel pump under the back seat. I should be able to hear it when on the driver seat but didn't. When I drive and turn off the car and try to start it right up it won't. What should I look for now?

Thanks.

 

Here's how to troubleshoot the main relay and its circuit:

 

After coming to a conclusion that I am not that skillful to testing out electrical components, I started researching similar problems. Many civics this year (89-91) have problems with starting the car shortly after driving it and noit being able to start until the car has sat for about 5-10 mins. There are 2 parts, a ingnitor and a main relay. Can someone tell me what the designated jobs of these 2 parts are. What would be the cause of me not getting a spark to my plugs when the car is warm after 20 mins or more of driving. I would like to gamble on one of the two but would like to see what I am dealing with. Thanks, for all the info so far.

 

The igniter drives the ignition coil to generate sparks. It is an electrical part mounted in the distributor. It takes 12 volts and a weak pulse from the ECU computer and generates a strong pulse to the coil. The coil is also mounted inside the distributor. Coils can become flakey when hot.

The main relay controls the power to the fuel pump and I think the fuel injectors. Usually with a main relay problem you will have sparks but the car won't start because there is no fuel being supplied.

 

I had the same problem with a 90 civic, startes fine when cold, but won't start when warm, let it cool down 15 min. and off you go. Also no spark at the time.

The problem was the main relay, the solder joints inside the relay were not that good from the factory.The main relay sends power to the fuel pump, and the ignition, this happens all the time that the car is on. It creates a lot of heat stress on thesolder joints, and they tend to fail whenhot, when they cool off they contract and remake the connection.

The car will still crank over, also a function of the main relay, but until the relay is cool enough I got no spark.

If you pry the plastic cover off of the relay, you will find inside a circuit board with a dozen or so solder joints. Reheat these spots with a good soldering iron, and any problem with bad connections should be solved.

This relay seems to be a source of a lot of problems for honda's from the 90's, check the problems solved page and you will find detailed instructionson how to make this repair.

Good luck