On 11:42 PM 06/06/02 -0400, Lee & Tracy Grimes said... >You may have identified a problem I had yesterday in the '89 Si ZC street >car. I have never dealt with any main relays in any of my CRXs over the >years but had an odd one yesterday that my just be my turn. > >The car has sat in the air conditioned garage for the last two weeks while >we were on vacation then started immediately for the first day back to work. >When ready to go to lunch on a pretty hot and humid day, the engine would >crank over freely but no the least bit of kick or fire. I checked and found >no spark at #1 or #4 cyls. I have a new distributor in it and was afraid >that was the problem but had no chance to check it. That afternoon, we had >a deluge rain storm cool things off and just as I was about to leave the car >overnight and ride home with someone, I tired the ignition just by chance. >It cranked about 3 seconds then started and drove home good as new. haven't >touched it since then and drove the truck to work. > >Would this main relay failure allow the engine to crank freely but eliminate >all spark? Is there a test to see if one is bad (may have a used spare >hanging around)? With 202,000 miles I certainly can't fault a relay for >dying now with no previous trouble ever. > >Lee
(* snip *) The main relay really controls the fuel pump and supplies power to the ECU. To check the main relay is pretty simple. You'll need a pair of jumper wires (alligator clips) and a digital volt meter (or a meter that can check both DC volts and continuity). Remove the relay and do the following: Apply +12VDC to connector/terminal 4 and Ground to connector/terminal 8. You should have continuity between connector/terminal 5 and 7. Apply +12VDC to connect/terminal 5 and Ground to connector/terminal 2. You should have continuity between connector/terminal 1 and 3. Apply +12VDC to connector/terminal 3 and Ground to connector/terminal 8. You should have continuity between connector/terminal 5 and 7. If any of the three checks fail then you have a bad main relay. --------------------------------------- The main relay terminals are as follows: 5 1 2 3 4 8 7 --------------------------------------- 1 = Battery (Positive) 2 = Ground 3 = To ECU 4 = Starter Switch 5 = Ignition Switch 7 = Fuel Pump 8 = To ECU --------------------------------------- While I've not experienced this in my CRX, I have in some of my past/previous cars and that is the ground. When the ambient surrounding temperature gets hot, it causes the metal in the ground wire(s) to expand which can sometimes be enough to add enough resistance on the wire to where you no longer have a good solid ground ~ you end up with a floating ground. If it happens again, what you can do is get a jumper cable (the kind used to jump a dead battery) and connect it to the negative terminal on the battery and to a good ground spot on the frame and see if the engine will fire up. If it doesn't, take it off the negative battery post and place it on an engine bolt somewhere (basically grounding the engine ~ there are at least three ground points... battery, and two engine, IIRC). And then there's always the possibility that it is your dizzy or some component related to it (i.e. coil and/or igniter). Best of luck! Robert K. Kuhn CRX Owners Group President (http://www.crx.org/southcal) 1990 Honda CRXsi (http://drive.to/jiggy) ICQ # 3714283 (nickname: godzilla)
