Its a 91 honda civic, I did a bench test after taking the new fuel pump out again as I said above and it worked fine. I have absolutly no idea whats wrong with it, could it be the ECU?? There used to be a code 20 on the ecu which was electrical load, but now its not flashing, I may have fixed it by putting new battery terminals and a voltage stabalizer on but I dont know for sure... When I turn the car to the on pos I dont hear a click from the Main Relay but when doing the haynes repair manuel check on it, everythings fine and I hear it clicking when I give the proper connectors power... I am out of ideas!!!!!!

 

For clarification,

1) When you say you did a bench test, I assume you mean that the isolated fuel pump removed from the car operates properly when supplied with battery power.

2) In an earlier post, I think you also mentioned that proper battery voltage is detected at the main-relay side connector at fuel pump.

(Also, have you done a fuel pump test similar to that described in the picture for a 1990 Civic?)

If statements (1) and (2) are correct, then what I was trying to say in my last post was that the problem may lie with the main-relay side and fuel pump-side connectors (located at the fuel pump) not making proper electrical contacts.

I don't think the problem is with either the ECU or ELD. Also, statement 2, if correct, seems to rule out a main relay problem.


[IMG]local://upfiles/25538/C40944BEC9B34C01B02E6CE74FCB58E1.jpg[/IMG]

 

Yes I supplied power to the pump and it worked fine. I also removed the relay and supplied voltage to the proper connectors and heard the relay click, and saw a jump in my voltemeter. But when I hook the main relay back up the the car it doesnt click when I turn the key to the on position... I did something similar to that test in the picture, but I will tyr that one and see if its all good.

Now for the connectors at the fuel pump, on the top of the fuel pump assembly there was a thick coat of tar, or undercoating, would that cause a problem to the connectors???

 

Delay testing the fuel pump connectors because, from what you are now saying, it seems that the main relay is not receiving any power when you turn the ignition key ON. Therefore, start by checking whether fuse #37 (15A) in the main fuse box or fuse #14 (10A) in the dash fuse box is blown. In the '90 Civic, these two fuses control the main relay/fuel pump circuit. Also test whether fuse #2 (Starter Signal) in the dash fuse box is blown. See the picture for additional important details on troubleshooting the main-relay harness.

[IMG]local://upfiles/25538/68FB460EF0DE4DADAE77B70870055529.jpg[/IMG]

 

Hehe dont I feel dumb, I did that test and it leaded me to the #14 which was blown, so I replaced it and bang fired up but soon died after about 5 min, so I thought maybe the pumps trying to hard cause the regulator is closed to much and it pops the fuse so I adjusted it and took it for a rip around the street and it was fine.. Any other ideas on why it could be blowing the fuse??? I feel unsafe knowing it may blow at anytime and I carry a little pack of fuses and pliers

 

Also, my Fuel pressure Regulator is not giving off any pressure readings, any thoughts on that guys?

 

That's great progress! I didn't know the fuel pressure regulator was adjustable. If this adjustment solves the fuse blowing problem, then you are done. If fuse #14 continues to blow, however, then look for a wire shorting out somewhere between fuse #14 and the main relay/fuel pump. Alternatively, the short also could be occurring in wires serving other components connected to fuse #14 (see picture).

[IMG]local://upfiles/25538/03659A085B4A4D189BB3E2BED6ECD1F0.jpg[/IMG]

 

Are you testing the fuel pressure as described in the picture?

[IMG]local://upfiles/25538/557A9728F5CB4A3397AF268E9857BE30.jpg[/IMG]

 

No its an aftermarket adjustable fuel pressure regulator, sorry forgot to add that.

 

Hi, I believe my problem is in the same category as yours, my Car has been running fine with no problems whatsoever, and one day I came out to start it up and it just wouldn't crank up, and I noticed the check engine light was on. So I just gave up trying to start it, came out the next day and it cranked up. I drove it, parked it, next time I came out to start it, same thing, Check engine light. I replaced the main relay, Tested the fuel pump, and it's fine. After trying to start it , with the ignition on, the check engine light randomly goes off, the relay clicks and the fuel pump starts wizzing, The car will Run fine, and when I turn it off and back on, the check engine light takes only a few seconds to click off, and the fuel pump starts whizzing. But when I try to start it in the morning, the check engine light will not click off. Does this have something to do with the ignition key switch, or the CPU? Any information would be very helpful, Thank's alot!