Running Lean

[rondofj]

no thanks, pumps are one of those things u buy brand new, I'm set on a Walbro GSS342, but peoples' different opinions are making me hesitate lol.. Which twin walbros are u after, has your tomei run out of flow?

For those rewiring - is it from the battery + terminal to the pump??

[bubba]

1x 044 mounted in tank is good for well over 500rwhp (my mate has one in his ~580awhp GTS4)

I paid ~$215 on eBay for my 044 a few years ago then paid a local performance shop ~$200 to fit it, that included them sourcing all the fittings, stock-type sock filter setup and rewiring.

Yes, it does get a little bit noisy when the fuel gets hot (low tank and city driving).

Edit: in response to the question directly above, you basically wire a constant voltage from the battery to a relay, to the fuel pump, then trip the relay with an ignition signal. If you just wire straight from the battery to fuel pump it will run all the time even with the car off.. also need a nice fat earth cable (I believe the variable voltage is on the negative side anyway).

Edited April 4, 2011 by bubba

[Randon_I_Am]

as for the wiring...

use what's going to the pumps positive to switch a relay, allowing the full 13.7 volts to go to the pump.

From the battery + terminal to a relay (you supply) from there to the pump. Neg from the pump to your own ground point (not going back to the ECU.

Here's a quick paint diagram i drew up

Not an easy task if you're not confined with solder or electronics...

[scotty nm35]

no thanks, pumps are one of those things u buy brand new, I'm set on a Walbro GSS342, but peoples' different opinions are making me hesitate lol.. Which twin walbros are u after, has your tomei run out of flow?

For those rewiring - is it from the battery + terminal to the pump??

My line is too small, the pump still has plenty to give. If im going to upgrade the lines, Twin walbro's (one 341 and one 342) will be going in. I plan to run one pump for each rail on the V6, that way if one fails I will know about it I hope...

I bought the Tomei s/h, Ive had no issues with it for a year. There is no way I would spend $600 on one new when there are much better pumps for that price.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=200471272130&ssPageName=STRK:MEWAX:IT#ht_1331wt_905

[Hanaldo]

Also running a Walbro GSS342 in my car with no issues. Plugged straight into my stock location, I used the stock wiring harness and sock and it fitted directly onto the stock cradle. I had absolutely no idea what I was doing and it took me 5 minutes to install. The only thing I did wrong was I somehow reversed the polarities meaning the pump was running backwards.

Rewiring the pump to run directly from the battery wasn't hard either. Took me about an hour, most of that was running the wire from the engine bay to the boot. Much, much quicker if your battery is in your boot lol.

Edited April 4, 2011 by Hanaldo

[rondofj]

Why are people using the stock sock and wiring when walbro pumps come with these items NEW? and lol at reversing the polarities.. Hoping I wont have to rewire - after the tune I'm hopin to reach a best of 220rwkw - after a hiflow and z32 (around end of year/next year ) maybe 260rwkw, and final step are the injectors - then hopin for 280-300rwkw.. So hope I dont have to rewire for now.. Do the Bosch 040 users have to rewire as well for this power goal??

[Randon_I_Am]

http://www.skylinesaustralia.com/forums/topic/253097-how-to-bosch-040-fuel-pump-in-r33-skyline-si-sii/

[rondofj]

thanks pat I have seen that before - they didnt rewire that one, just the terminals to the pump

[Randon_I_Am]

Ar, i didn't read through it, must have been another one with the re-wire from battery

[rondofj]

Just remembered, did u guys have to get a new pump clamp holder / bracket mount to hold the pump in the existing stock cradle??

[Randon_I_Am]

hose clamp...

[SlowSkyline]

was the tuner toshi? I had a similar problem when he tuned my car... couldnt get it running right, was leaning out massively, he did a tune for me after 9hrs of stuffing around and it was worse than stock.. and reckoned it was the fuel pump.. that was new that i installed 2 weeks earlier.

Turned out it was a partically blocked BOV that caused all my leaning out issues.

[rondofj]

how does a blocked bov cause it to run lean - bov is where the return air goes when u release the throttle isn't it? If thats blocked, the air will back track onto the turbo, causing it to stop quick? Dunno where the leaning issue comes in here - leaning is basically too much air (boost) and not enough fuel

[DVS JEZ]

Partially blocked BOV? Please explain?

[rondofj]

yes dont really understand that one

[sinistaGTR]

WTF..... this one im interested to hear about the blocked bov causing lean issues

[gotRICE?]

Lithium runs one of the 255L/H walbro's in his R33 making 300rwkw with no wiring modification, for the 14v that is. No problems.

Same with mine, i just dropped it in. Wired the two wires and away i went. No problems with low fuel or anything.

I dunno why people go on and on about them being noisey. Sure you can hear it when it primes, but you can hear the stock one too. Other than that it might as well not be there. Cant hear a thing.

If you after a easy cheap pump that will do the job, the Walbro is the way to go. The bosch sounds like (from what i read here) its a huge hassle to make it fit. Cutting bits off here and there, and cable tied to the bracket. lol. The walbro just fits. You only need to wire it. Two wires. SOOO hard.

[rondofj]

Walbro is mine then. 2 wires. They come with the pump dont they, so all u gotta do is hook them to the pump terminals and then plug them to the plastic lid connector, correct? Is that all? So why does everyone still use the stock wiring and socks when these r supplied with the walbros?

[gotRICE?]

Walbro is mine then. 2 wires. They come with the pump dont they, so all u gotta do is hook them to the pump terminals and then plug them to the plastic lid connector, correct? Is that all? So why does everyone still use the stock wiring and socks when these r supplied with the walbros?

They dont have a plug on both ends, it has one for the pump. The other end you use the supplied connectors. You Just have to wire it into the stock wiring. Positive and Negative. Pretty basic.

The reason people use the stock sock is because it sits on a better angle than the walbro sock.. It can cause surging when the fuel gets low. More so on tracks.

If you get one you will see.

I havnt, as i said, had any issues yet and my low fuel light came on the other day.

Edited April 4, 2011 by gotRICE?

[QWK32]

Walbro is mine then. 2 wires. They come with the pump dont they, so all u gotta do is hook them to the pump terminals and then plug them to the plastic lid connector, correct? Is that all? So why does everyone still use the stock wiring and socks when these r supplied with the walbros?

the walbro has a moulded two pin socket on top of it, not the screw terminal type like the bosch ones have. i used the standard wiring because the plug for the stock pump was exactly the same as the moulded socket on the walbro pump, the R34 may be the same. this meant i didn't have to stuff around chopping, soldering and insulating a join. i also used the new sock provided with the walbro, it looked basically the same as the stock one and i haven't had any issue with fuel supply and i sometime run it down till the fuel light comes on .

i guess the other guys are saying the sock provided with the walbro doesn't sit down as far as the stock one therefore not providing a good enough pickup when the tank gets low. just have a look at everything when you get the cradle out of the tank, check the mounting position and how it is with the new sock and the old one. you may find there is bugger all difference and then use the new one. if the R34 fuel pump electrical plug is the same then it will be even easier, it will basically be plug and play.