Fuel Pump Relay Question.

Grants · Post by **Grants** » May 1st, 2006, 8:46 am

http://eunos30x.com/info/CEL%20Codes%20 ... mplete.pdf

RacerX · Post by **RacerX** » May 1st, 2006, 9:51 pm

My car seriously sucks :*(

RacerX · Post by **RacerX** » May 4th, 2006, 5:44 pm

Ok so today my car was dying out again and I dont know if this was happening before but its happening now.

when it stalls out, sometimes I hear the relay click if I atempt to start but if I just leave the key on when it dies and and do nothing, sometimes after about a minute to a minute and a half, just depends I guess ? the relay clicks and the fuel pumps re-primes and viola - restarts...worked 6 times today XD

Is the ECU signal sent to the fuel pump first and then the sensor or whatever and then the relay or what should I be looking to replace now ?

Grants · Post by **Grants** » May 4th, 2006, 11:33 pm

So you've swapped both the EGI relay and fuel pump relays?

Change the 2 fuses associated with it:
Engine fuse under the dash and
Fuel Injector fuse in the engine bay.

That takes care of all the moving and replacable parts in this circuit. The only other thing it can be is a fault in the hard wiring.

What your gonna have to start doing is looking for voltages (or lack thereof) while its failed.

RacerX · Post by **RacerX** » May 5th, 2006, 12:07 am

Yes sir. I've replaced/swapped both with various relays. All fuses are brand new with less than 1 hour on them. Engine bay and fuse box interior. I did notice whern it happened again for the elevntybillionth time tonight if while coasting in gear but only sometimes, if I rapidly push the gas pedal like a spaz, it will bog but 'somewhat' stay running but only aound like 300 - 400 RPM and it jumps up and down but if I try taking off with any gas pressed, it will die out...so..if I coast, push the gas pedal like 50 times, it boggily stays running barely, no power as if only one piston is getting fuel or something and continue to mash the gas a bunch of times after about 20 seconds of doing this, the RPMs will shoot up and I can resume driving until it happens again with full power returned.

RacerX · Post by **RacerX** » May 5th, 2006, 6:57 pm

OK I think I may need a new fuel pump ...I am going to buy one but I really dont want OEM because I hate the K8 motor and plan a soon future swap with either the DE or ZE but anywho, For the time being I need my car to go lol so I was wondering if a WALBRO 255 LPH fuel pump will be too much for stock fuel lines, stock fuel rails, stock injectors- Will it be 'too' much fuel for my basically stock K8 ? Shoul dI go with a 190 LPH instead for my stockness ?

Appreciate any info guys

Grants · Post by **Grants** » May 5th, 2006, 8:06 pm

I can't imagine its your fuel pump. If the relay is dropping out (which it shouldn't) it still sounds like a control circuit fault.

ktmrider · Post by **ktmrider** » May 10th, 2006, 10:46 pm

I just asked the same question on the pump, the stocker will be fine even for the ZE. I found plenty on eBay for around $60 US if you can wait a few extra days else Autozone has them for $130 US. Apparently the RX7 pump is also OK to use if they are easier to source.
There is a good troubleshooting section in the Online Manual for fuel related items. I had a different car do similar things ( stalling, poor running, poorer fuel mileage ) and found the vacuum line to the regulator was cracked. This caused a weak signal to the regulator and it delivered too much fuel. Check both the line and the regulator. Good luck, hope you figure it out.
Edit, I noticed you have a CAI, make sure you have a good vacuum signal for sure....

mab · Post by **mab** » May 11th, 2006, 12:12 am

check fuel pressure and make sure you u get a stethascope and listen for the injectors to click on and off

RacerX · Post by **RacerX** » May 11th, 2006, 12:28 am

ktmrider wrote:I just asked the same question on the pump, the stocker will be fine even for the ZE. I found plenty on eBay for around $60 US if you can wait a few extra days else Autozone has them for $130 US. Apparently the RX7 pump is also OK to use if they are easier to source.
There is a good troubleshooting section in the Online Manual for fuel related items. I had a different car do similar things ( stalling, poor running, poorer fuel mileage ) and found the vacuum line to the regulator was cracked. This caused a weak signal to the regulator and it delivered too much fuel. Check both the line and the regulator. Good luck, hope you figure it out.
Edit, I noticed you have a CAI, make sure you have a good vacuum signal for sure....

I have a code 16 still and have no idea how to get rid of it but I got lame-o-zone silicone lines or whatever now my engine runs worse lol..maybe i'll put it back to stock and run a duct up to the air box or something

Grants · Post by **Grants** » May 11th, 2006, 6:36 am

But aren't we dealing with an intermittant fault that is sometimes no fuel / sometimes no spark? I've been working on:

Yup..pulled the back seat out and everything.its a very strange problem..sometimes I get no fuel and other times I get no spark..o.O

IF that relay is switching off, you need to know WHY. Because it shouldn't be. Run a jumper to it (while running) so it can't switch off. That will prove it.

RacerX · Post by **RacerX** » May 11th, 2006, 5:41 pm

Which pins do I jump ?

Grants · Post by **Grants** » May 11th, 2006, 6:13 pm

You'd need to run 12 volts to the BLACK / RED wire on the relay. Don't pick up the 12V from anywhere on the relay so you know you've got a good supply. That will bypass the relay altogether. Only do it when its running.

RacerX · Post by **RacerX** » May 11th, 2006, 8:18 pm

well I got really pissed off at my car lol and I spent like 4 hours working on it making sure everything was snug n' fit and whatever. Anywho...when I put on my CAI and eliminated my factory air box, I rerouted all the vacuum lines and everything but anyways I just so by chance happened to be pulling vacuum lines off while it was running just for kicks n' giggles basically and soon as I pulled off the one that went into the bottom of that little sensor thingy majig that was connection to the MAF/VAF ( The one with a vacuum lime on dead bottom, sensor plug and black mitsubishi cap plug on top ) it smoothed out the idle like it was brand new - I removed the bottom one. So what I did was let it run for about 45 minutes shutting it off frequently and turning it back on..viola..didn't die a single time or stall out on me. The IDLE was so smooth I thought it was a completely different car altogether..ran way better too =)

Anywho so I took the little plug off my CAI nipple and I hooked it to that so it was getting a controlled amount of air and put the line I had plugged to which ran behind the TB to the little sensor thing and now it runs perfectly. I guess when I go on my 2 1/2 hour drive tomorrow i'll see if that fixed it lol..i'll try to draw up a diagram of what I mean if need be.

mab · Post by **mab** » May 11th, 2006, 10:39 pm

then it must be your fuel pump. birdge it through the ground and fuel pump in your diag connection and see if you can hear the pump running