nor11384

iTrader: (1)

Guys ive been trying to find how tos for fuel pump rewire but i cant get a clear answer on whether after the rewire the car will run rich or not. I saw in one thread that you have to get an aftermarket fpr after the rewire to control fuel pressure? Is this true? i have a walbro 255 which is less than a month old and it started making crazy loud whine. Im willing to rewire this thing but i dont want to have to buy a fpr and retune. When you have a wife and kids its hard to just throw money at this thing like this. I get it, you have to pay to play but right now cant do it. Can someone shine some light on this for me please? Need to know...

RightSaid fred

Put the stock pump back in without a hotwire.

Next........measure the pressure.

Next, fit your walbro pump.

Measure the pressure again (it always goes up at idle).

Then hotwire it.

Measure the pressure again (it goes up even more).




When you've done that, you'll know that you've cocked it up (because the pressure increased at idle) and you won't have to ask on the interweb.


Then you'll be far more knowledgeable than the 99% on here who've never measured fuel pressure.

Problem solved.

Ferp

Hardwiring your fuel pump is easy if you're comfortable with wires and a soldering iron. I did mine in thirty minutes, had to look up where to run what on a 4 pin relay but other than that it was easy. There are a few reasons for doing this. My Evo is 22 years old and would randomly run lean under power. The fuel pump wasn't getting enough power (thank old wiring and a weird relay system in the Evo 4/5). I've read of other people saying their cars "rev bounce" less at low rpm/low speed, and that the off boos driving is much smoother. I never noticed any of that in my Eclipse or my Evo, but the fact you're providing a steady stream of power to your pump is a good thing.

My stock FPR handled my DW200 no problem. Might be an issue on larger pumps. However, I had no reason to touch my tune.

kikiturbo

this really depends on how you hotwire the pump, i.e. which of the two circuits you replace with the hotwire..

nor11384

iTrader: (1)

I don't have a stock pump to put in. I bought the car with a walbro 255 and it took 2 years of ownership to for it to get super loud one time or at least for me to notice it do it. Bought this new pump and it took 2 weeks or so for it to do it. Now, it was hot that day and I drove it for a while. I'm pretty mechanically inclined but when it comes to wiring I'm not the best. I can saughter and do clean wiring but where goes what is the problem. I don't mean to bother anybody I just want some clear answers because with a wife and 2 kids I don't have many tries at this. Whatever I'm gonna do I gotta do it right one time which is my I'm asking you guys for help. So if I do rewire it I WILL need a fpr and a tune or just one or the other? Car always ran fine without rewiring anything. Could it be the new pump is defective or is there a chance factory wires are getting old?

Biggiesacks

When you do a rewire you may need tuning because generally you will run a little richer once the rewire activates. The key here is that you will use a relay to activate your rewire and you should trigger that relay with a hob switch. The hob switch is triggered by boost so untill you hit boost you are still running through the factory resistor and will not over run the factory fpr with just a walbro 255. Also make sure you upgrade the ground wire for the pump too, many forget to do this.

nor11384

iTrader: (1)

damn...see what you said there sort of made sense in theory but when it comes to rewiring the thing im lost...if i had a how to saying what wire connects to what i can do it but the only how to on here is old and the pics no longer work...

Ferp

http://lancerregister.com/showthread.php?t=459924

nor11384

iTrader: (1)

thats a good thread but i wont bull****...im still somewhat confused lol...ive installed clutches, headgaskets, etc but cant figure out a couple of wires...wtf...

Ferp

If you can do a clutch or a head gasket I promise this will be a 1/10 in difficulty. Just take your time.

nor11384

iTrader: (1)

ok, ive been looking at the stm kit but i read somewhere they were burning relays...any suggestions on a kit?

Biggiesacks

bad wiring jobs burn down cars. If this isn't something you are confident in doing, you should definitely consider having it professionally installed.

nor11384

iTrader: (1)

yeah i know...thing is, there is no professional around here i trust so i would rather study this and do it myself...

Biggiesacks

A few tips, Make sure to add a fuse as close to the power source (battery) as possible. Choose a good location for your chassis ground. Try and follow the factory harness as much as possible, use grommets when passing through the chassis. I will usually try and go through factory grommets. Use lots of zip ties to keep things clean and tidy. Use a switched source for the relay coil / hob switch part of the circuit.

nor11384

iTrader: (1)

What is a switched source? Also, my battery is in the trunk so it should be much easier. I don't have to run any wires to the front of the car right?