guamie

My car had a greddy turbo kit on it previously. Too lazy to swap out the 255 walbro fuel pump when i went back to stock. Would having the fuel pump cause any adverse effect on my motor?

s2000Junky

No not at all.

shind3

Have you seen any data that shows the stock FPR isn't big enough to bypass enough fuel to not change fuel pressure with a 255lph?

Or is that just your opinion?

Also, OP, you are aware there are two very different styles of fuel systems for an S2000 right? So shouldn't you specify which one you have a question about?

s2000Junky

The question was, "Would having the fuel pump cause any adverse effect on my motor?" Not whether or not fuel pressure may increase. Either way is safe and therefore moot, because a higher then stock fuel pressure will have no adverse effects on the engine. Closed loop will account and regulate any possible added fuel to maintain the engines/ecu targets, and when open loop transitions the engine would simply run richer. Thats my data logging experience. Now, that pertinent element aside, in theory fuel pressure will not increase due to the factory fpr being in place since its a fixed regulation/non adjustable, but instead line pressure would. Either way, no harm, no fowl.

This is based off a MY 00-05

riceball777

I have ran a walbro 255 on my stock non boosted s2000 for long periods of time before with no issue at all.

Chance S2K

Nope, the stock ECU will still mandate the correct amount of fuel to put into the car. Leave the Walbro in there, you don't need tuning on a fuel system until you start fussing with injectors.

I had my Full Blown 290lph fuel pump in my car for months before getting the car tuned with a turbo. Made absolutely 0 difference.

Edit: Dropped a letter.

guamie

Forgot to mention that I have an MY02. The only thing I didn't like was when I took the car down to Homecoming 3 (6hours), the fuel pump was noisier than usual even with a full tank of gas. Thanks for your guy's answers!

shind3

The question was, "Would having the fuel pump cause any adverse effect on my motor?" Not whether or not fuel pressure may increase. Either way is safe and therefore moot, because a higher then stock fuel pressure will have no adverse effects on the engine. Closed loop will account and regulate any possible added fuel to maintain the engines/ecu targets, and when open loop transitions the engine would simply run richer. Thats my data logging experience. Now, that pertinent element aside, in theory fuel pressure will not increase due to the factory fpr being in place since its a fixed regulation/non adjustable, but instead line pressure would. Either way, no harm, no fowl.

This is based off a MY 00-05
[/quote]
Sure, but if I could get my fuel trims closer to 0 and not have to run richer than I need to at WOT just by changing to a stock fuel pump, I would.

And if the FPR is big enough to bypass the extra flow from a Walbro 255 then yes it will not be change anything except for some warmer fuel. I asked if you knew the FPR was big enough for this to happen without raising fuel pressure especially at idle.

But the 06+ have a different FPR. don't know if it can bypass the same as the earlier ones.

So the answer could've depended on that variable. But the engine itself will fine fine, yes. And I guess that was the question. You win, lol.

s2000Junky

Walboro 255's are noisy. Other larger aftermarket pumps are not. I run a FB340 (with a stock ecu) its pretty quiet.

s2000Junky

The question was, "Would having the fuel pump cause any adverse effect on my motor?" Not whether or not fuel pressure may increase. Either way is safe and therefore moot, because a higher then stock fuel pressure will have no adverse effects on the engine. Closed loop will account and regulate any possible added fuel to maintain the engines/ecu targets, and when open loop transitions the engine would simply run richer. Thats my data logging experience. Now, that pertinent element aside, in theory fuel pressure will not increase due to the factory fpr being in place since its a fixed regulation/non adjustable, but instead line pressure would. Either way, no harm, no fowl.

This is based off a MY 00-05
[/quote]
Sure, but if I could get my fuel trims closer to 0 and not have to run richer than I need to at WOT just by changing to a stock fuel pump, I would.

And if the FPR is big enough to bypass the extra flow from a Walbro 255 then yes it will not be change anything except for some warmer fuel. I asked if you knew the FPR was big enough for this to happen without raising fuel pressure especially at idle.

But the 06+ have a different FPR. don't know if it can bypass the same as the earlier ones.

So the answer could've depended on that variable. But the engine itself will fine fine, yes. And I guess that was the question. You win, lol.
[/quote]

Short and long term fuel trims fluctuate, they are never just at 0 all the time no matter the fuel pressure. However if centering them close as possible is your goal/concern, pick up an adjustable fuel pressure regular and bring it back to balance. Of course this is all on the premise that the fuel pressure has indeed changed with a bigger pump and stock fpr, which I don't recall seeing. Yes, I do win