Will a Walboro 255 fuel pump affect a stock car? Actually my car is not stock, i have a Works p2 reflash. But putting a walboro fuel pump should not affect performance of any sort right? From what i know, an upgraded fuel pump does not mean it will push more fuel to the injectors, but its just capable of doing so. Any comments on this?

Also because i'm waiting mitsubishi to ship me a stock fuel pump, but its been on backorder for awhile, and i am just opting to get a walboro. Hope i get some responses on this, or maybe someone want to sell and ship me their fuel pummp.

Yes, it will affect the performance w/o fuel tuning. It will run richer in the upper RPMs and under boost. I changed mine just prior to my tuning session and to me, it ran like crap until the extra fuel was dialed out and it smoothed out nicely. If all you have is a Works flash, replace it with a stock pump. This subject has been covered and debated for awhile. Do a search.

What happened to your stock pump?

better safe than sorry....changing the pump wont effect performance that much. i changed mine for the summer and i have a dynoflash, 3" TB, hallman prox. the car defs feels a little weaker but a hell of alot smoother

^ Dynoflash offers a free pump upgrade flash. Do it. If you are very mildly modded, keep the stocker. It can handle stock boost. I upgraded mostly due to very hot weather where the stock pump can suddenly drop output under load and repeated pulls.

So your saying if i got the dynoflash now and get a fuel pump later, Al will flash it the second time for free?

My car actually ran better this winter with a Walbro and P1 flash from top to bottom. I believe it even idled better, but that is probably the placebo effect . I suspect this is due to how lean Works programs. However, I had removed the pump prior to installing my P2. I use my old Walbro for my supercharged Integra for the purposes of testing. I just didn't feel comfortable leaving the heavily used pump in my Evo.

I'm almost positive the pump upgrade is free. You pay shipping though.

Correct. The fuel pressure regulator and cycle rate of the fuel injectors (as set by the ECM) determine the amount fuel getting to the cylinders. Upgrading only the pump should have no affect on your car's performance unless the stock pump was defective or the upgrade exceeds the capacity of the FPR. The reason many tuners are recommending an upgrade with modest mods is the stock pump can get into some sort of "run-out condition" ealier than expected causing a lean fuel mixture.


Speedlimit...

All I can say is that when I put my walboro in my car felt like a slug. I had ran a 12.9 a week prior, installed pump, had trouble breaking mid 13's until I leaned out my SAFC a bit, I finally ran a 13.3 that night but was still pissed about my performance. Went and had my car dyno tuned 1st pull was 234 and was running super rich even though I had it leaned out a bit. By the time tuning was done I was putting 296.5 to the wheels. He said the pump had made it run this rich that is why I noticed such a lack of power after install.

Shane

I installed one last week prior to the Dynoflash tune down in Dallas..

It ran pig rich on the way down there! We gunned it in fourth and fifth and it bogged down hard. Fuel consumption was also higher than normal. I was cruising 90ish all on interstate and I made only 210 miles on the tank.

Of course, after I had the custom tune it was night and day. I think the car actually runs better across the board now, esp at WOT. Fuel mileage is close to where it was prior to install. I went 264 miles yesterday in a mix of highway/city and I only put 11.9 gallons in the tank.

So if you're gonna have it re-tuned, then without a doubt, go for it. Otherwise, stay with the stocker.

I cannot see how anyone who installed a Walbro can say they didn't feel a difference in the way the car runs before fuel tuning. Mine ran like crap for the short time before my tune. It felt sluggish, decrease in power up top and idled rough. Even Dynoflash recommends staying out of boost until you tune it or it can foul the plugs due to the rich conditions.