Just did a replacement (D16a6) motor swap into a 90 Si hatch. Go to start it, sounds like it cranking, but getting nothing. Go through the obviously checks, then
-I check to see if I'm even getting fuel and I'm not.
-Then check to see it I'm getting power to the fuel pump, I am.
-Then I put a jumper wire between the BLK/YLW and the YLW/BLK wires off the main relay and turn the ignition switch to on, and sure enough fuel comes out from the return line. (yes into a container)
-But when I connect the main relay back to the 5-pin connector and turned the ignition I get no fuel. Does this mean I have a bad main relay.

Thanks

First steps on this page. When i put the jumper wire on and turn the ignition fuel comes out.

Again do i need a new main relay.

 

Sounds like it to me. If everything around it on both ends seems to work then you pretty much hit the nail on the head. There are a lot of posts about fuel problems on EFs here on HT and I would estimate that 80% of them are fixed by getting a new main fuel relay or fuel pump.

This was the case with my CRX. I was getting irratic fuel numbers. Like one week I would get double the fuel economy as I did the week after while driving the exact same route everyday. Then my car wouldnt start when I would refill fuel and just randomly off and on. So I posted on HT about it and a few people sugested the Main Fuel Relay.

Sure enough that was the problem. I bought the relay from Honda for $71 Canadian and dont bother going out to Pep Boys or where ever to look for a generic one, because they dont exist. Only Honda has them for some reason.

Here is a link to my threads regarding my fuel problems and people's suggestions and how to replace the MFR which it seems that you already know how to do .

https://honda-tech.com/zerothread?id=939721
http://honda.hybrids.jp/tech/p...shtml <--- Good Info

The part number for the relay is PN 39400-SH3-003

I hope this helps.
CRX Forum

 

If you're up for it here's something to try.

Go to Radio shack get a desoldering gun. $5
Get a soldering gun. $5
Solder $2

Remove main relay. Check for little rings around the joints. These are called "dry joints". You gotta look closely.

Desolder it. Resolder it.

It gets to 110 deg out here in the summer. My car started everytime.

 

being as this picture shows (sorry this is kind of off topic) do u HAVE to remove the fuel tank to friggin change the fuel pump? some say yes, some say no, so pls someone let me know because i have to change the fuel pump anyways, and im lazy

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b2o-vtec &raquo;</TD></TR><TR><TD CLASS="quote">being as this picture shows (sorry this is kind of off topic) do u HAVE to remove the fuel tank to friggin change the fuel pump? some say yes, some say no, so pls someone let me know because i have to change the fuel pump anyways, and im lazy </TD></TR></TABLE>

i changed the fuel pump in my 90 crx si and i cant see how you would change it without removing the gas tank...its not too difficult though, jus hope you dont have a full tank of gas when the pump goes out.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eda6 hatch &raquo;</TD></TR><TR><TD CLASS="quote">If you're up for it here's something to try.

Go to Radio shack get a desoldering gun. $5
Get a soldering gun. $5
Solder $2

Remove main relay. Check for little rings around the joints. These are called "dry joints". You gotta look closely.

Desolder it. Resolder it.

It gets to 110 deg out here in the summer. My car started everytime.

</TD></TR></TABLE>

is it difficult to desolder and resolder it? im really considering it but dont want to mess up the relay in any way.

 

The picture kind of sucks but if you look around the larger solders/joints there's some brown rust looking residue, it can be scraped off. Would that be adversely affect the relay. I think I'll try soldering later today.

 

http://www.marklamond.co.uk/ho...y.htm

 

I just cleaned up the soldering on mine added a bit here and there at it's worked fine for 3 years now!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Foowee &raquo;</TD></TR><TR><TD CLASS="quote">http://www.marklamond.co.uk/ho...y.htm</TD></TR></TABLE>

i have this link but i havent done too much desoldering or soldering period. also the link doesnt show the actual soldering part, so i need more guidance on that. is it something that someone who hasnt really soldered before could attempt?

 

It was the engine harness ground wire the gets grounded to the thermostat. I'm an idiot. The motor still does't start. But I'm getting fuel and spark. I think I just need to set the timing.