USDM sI

having major fuel problems... no signal (voltage) to the fuel pump at all,
if anyone knows i was wondering. if the ignition switch is bad, will it not send power to the fuel system?? anyone.....

BiG ChOr!Zo

iTrader: (1)

http://techauto.awardspace.com/ignitionswitch.html

4drEF

If the ignition switch were bad, then it won't send the signal to the main relay.
The main relay sends the signal to power the fuel pump.

USDM sI

cool, always good to learn something new... however it didnt specifically answer my ques.
1. the car is a 91 civic si (the recall on civics was only 98-99)
2. you cannot bypass the electrical switch on this car because the main relay is the vehicles final step in triggering the fuel pump (the main rely is powered by the electrical switch or the blk/yllw and white wire)
have you ever seen anything like this in an EF,
the car is 100% stock, was a b series then i got the shel and am putting her back to o.g. dont know too much bout b-swaps so... is there anything you are maybe supposed to bypass? and tht i need to put back to originall??
thanks again

USDM sI

right! does anyone have links to a fsm for ignition schematics?

(91 civic si)

4drEF

A B-swap doesn't mess with the fuel pump/ignition switch at all.

Your original question seems to be asking what to check if you aren't getting power to the fuel pump. The recall notice and the bypass thing in your second post really don't fit your first question at all.

the main relay on these cars fail commonly. The link above from Big Chorizo shows this schematic

Immediately before that pic it tells how to bypass the ignition switch - I think that conflicts with statement number 2 in your second post.

What you really need to do is make sure your ground wire to the fuel pump is good.
After that, troubleshoot your main relay.
Check for power on the Yellow wire to the fuel pump.
Likely this is what you are doing already - but this time check it at the main relay.
If you get power at the main relay, but not at the pump then it could be very likely that the previous owner installed a fuel cut out switch as a form of deterring a car thief.

If you still don't get power on the Yellow wire, even at the main relay, then troubleshoot the main relay or substitute a known good one.

If it still has the same issue then move on to troubleshooting your ignition switch.



More on the main relay.
http://www.tegger.com/hondafaq/mainr...ion/index.html



.

USDM sI

sorry really busy trying to get this thing going.....anyway, my main problem is theres no voltage to the pump, however im taking all possiblities into concideration.......i have about 4 main relays three which test good. also two ecus, both still start cars. i heard a rumor about ignition switch. can you think of any other possibilities?

4drEF

I wrote this above, but to make it easier to read....

1) If you don't have voltage AT the pump then try the same wire at the MAIN RELAY.
- Check for hidden fuel cutout switches if you get power at the main relay
- If you don't get power then try a different main relay or trouble shoot yours
2) If your main relay is good then troubleshoot the ignition switch.
3) If ignition switch is good then check for continuity on wires from ignition switch to main relay.
- If there was ever an alarm installed then there could be more wires cut (auto start does this)
- There may be a theft deterrent kill switch someplace

It isn't a complicated system.
That's all there is.
done.

USDM sI

no kill switch, all wires are getting constant power on the ignition switchxcept fot the blk/wht wire, you know what that is by any chance?? . the solder points and internals seem to be fine...

hybridmiklo

Why don't you freaking check voltage to the main relay. If it gets voltage than the switch is good.

USDM sI

Very clever
so far i found that there is voltage to the relay the harness is giving off proper power and resistance between the wires that the fsm refers to show that it is fine.
no voltage at pump but 12v coming from relay w ignition on.. so im still digging