Main relay - Houston-Imports.com

silver_ek · 07-23-2012, 01:35 PM

Just bought a 93 civic hb cx. Problem im having is pointing towards te main relay. I try to start my car and at times itll start with no problems and ill drive it all day with no issues. But sometimes itll start and immediately die when i release the key. Changed fuel filter and plugs and still does it. I do notice i do not hear the fuel pump te times it starts, so i cycle the key and then i hear the pump and itll start right up. Upon searching i found the problem has to be the main relay, what is the part number for this part? Is thw fuel pump relay the same thing? Thanks for any help. Yes i searched but i come up with different parts.

CB4door · 07-27-2012, 10:40 PM

Okay I have had the same problem so this is what i find out

ok #1 when you start the car you release the key engine dies that is your ignition switch

#2 fuel pump not prying usually are 7 things wrong 1 of these is your problem maybe
1-fuel pump fuse is blown /srs
2- main relay hot outs /bad relay
3- ground issues on a thermostat housing
fire wall by the ecu
under driver seat
4- bad fuel pump
5-ignition switch
6-bad ecu
7-if running jumper harness check wires for brakes/ corrosion

GS-RTEG · 07-27-2012, 11:23 PM

Never had this problem but to answer your question, the main "fuel" relay does control the fuel pump. If you can locate it, you should be able to take the cover off and physically look at all the solder points. You'll be looking for tiny cracks. Over time, especially with these older hondas the heat and vibrations can cause the relay to start acting up. Easiest way to eliminate the relay from your suspicions would be to maybe swap it out with a known good one out of a buddies car or possibly grab one from the junk yard to try out. It sucks, but usually it ends up being something small and simple like that that'll make you go spend a bunch of money chasing the problem.

silver_ek · 07-31-2012, 01:10 AM

Thanks for ur replies. Reason why i say its the relay is cuz SOMETIMES on the click right before turning the car on i do not hear the fuel pump or the click the CEL does and thats when it wont start. Ill cycle the key on and off until i hear the pump and CEL gives of a click when it turns off. I have thought of it being the pump but if it were then my car would never start and thats not the case. I just sometimes dont get the 3rd click to engage the fuel pump prime. Thats when i researched for days and concluded that with this 100*+ weather, the main relay was the cause due to the solder connections.

07-23-2012, 01:35 PM	#1
silver_ek JDM BLAH BLAH FKN BLAH Join Date: Aug 2007 Location: eagle pass,tx Posts: 2,068 Car: srt4, dc2 teg	Main relay Just bought a 93 civic hb cx. Problem im having is pointing towards te main relay. I try to start my car and at times itll start with no problems and ill drive it all day with no issues. But sometimes itll start and immediately die when i release the key. Changed fuel filter and plugs and still does it. I do notice i do not hear the fuel pump te times it starts, so i cycle the key and then i hear the pump and itll start right up. Upon searching i found the problem has to be the main relay, what is the part number for this part? Is thw fuel pump relay the same thing? Thanks for any help. Yes i searched but i come up with different parts. __________________ FAIL

07-27-2012, 10:40 PM	#2
CB4door on the run Join Date: Feb 2010 Location: Nac , TX Posts: 1,226 Car: 97 4door ferio	Okay I have had the same problem so this is what i find out ok #1 when you start the car you release the key engine dies that is your ignition switch #2 fuel pump not prying usually are 7 things wrong 1 of these is your problem maybe 1-fuel pump fuse is blown /srs 2- main relay hot outs /bad relay 3- ground issues on a thermostat housing fire wall by the ecu under driver seat 4- bad fuel pump 5-ignition switch 6-bad ecu 7-if running jumper harness check wires for brakes/ corrosion

07-27-2012, 11:23 PM	#3
GS-RTEG Pimp mode on(x) on( ) Join Date: Jan 2009 Location: Baytown Posts: 1,340 Car: 4dr GSR, Type R DA	Never had this problem but to answer your question, the main "fuel" relay does control the fuel pump. If you can locate it, you should be able to take the cover off and physically look at all the solder points. You'll be looking for tiny cracks. Over time, especially with these older hondas the heat and vibrations can cause the relay to start acting up. Easiest way to eliminate the relay from your suspicions would be to maybe swap it out with a known good one out of a buddies car or possibly grab one from the junk yard to try out. It sucks, but usually it ends up being something small and simple like that that'll make you go spend a bunch of money chasing the problem.

07-31-2012, 01:10 AM	#4
silver_ek JDM BLAH BLAH FKN BLAH Join Date: Aug 2007 Location: eagle pass,tx Posts: 2,068 Car: srt4, dc2 teg	Thanks for ur replies. Reason why i say its the relay is cuz SOMETIMES on the click right before turning the car on i do not hear the fuel pump or the click the CEL does and thats when it wont start. Ill cycle the key on and off until i hear the pump and CEL gives of a click when it turns off. I have thought of it being the pump but if it were then my car would never start and thats not the case. I just sometimes dont get the 3rd click to engage the fuel pump prime. Thats when i researched for days and concluded that with this 100*+ weather, the main relay was the cause due to the solder connections.