whacky wild inflatable flailing arm fuel issue/pump

[EsChassisLove]

So recently my fuel pump (walbro 255...cheap shit.) has started to "whine" for a few seconds at start up. Only when I havnt ran the car for a long period of time. Obviously, it might be time for an upgrade.

Also, when I start the car cold and drive, my AFRs are good. BUT, Lets say I drive for awhile, get the car warmed up, and then park it, come back 5 minutes later and start it up again to drive, it leans the fuck out.

I'm talking stupid lean. pure white spark plugs, EGTs at 1100 degrees during idle when its normally 900 degrees, backfiring like crazy, etc.

I checked my fuel pressure while this occured, havnt lost any pressure.

The only way to richen it up is to get in my PFC Commander and add fuel to each injector. Like 10+% worth to each one. This ONLY happens when the car is warm and after its been shut off then back on.

After awhile of driving it richens back up to what it should be, then in mid drive I gotta take away all that fuel I gave the injectors.

Any ideas? Could it possibly be the fuel pump? Either way I'm thinking of switching out to a Denso 260. Anything must be better than this $99 pump lol

[EsChassisLove]

Coolant temp sensor possibly...?

Fuck it replacing both for good measure.

[90hatchie]

walbro pumps suck plain and simple
they like to burn out
have you run the car low on gas before

i had same issue
went to a denso pump and issue went away

[EsChassisLove]

I always filled up at 1/4 tank. I don't like to run low on any pump

[TheRealSy90]

http://gifnation.com/albums/psychedelic/wwiaftm8gy.gif

[Firestorm]

if your fuel pressure is still good, it's definately not a fuel pump issue.

[Couped_up'd]

Go get a deatschwerks pump. The problem seems to be your fuel pump.

[bb4_96]

i wouldnt start with the pump

[EsChassisLove]

I'm gonna start with the coolant temp sensor. Only a $30 part. Wouldn't hurt to change it

[HPKMotorsports3]

damn i got excited till i found out it wasnt wacky wild inflatable flailing arm tube man...:cry:

[fliprayzin240sx]

Well, walbro is notorious with slowly dying and not hold the pressure on WOT.

The only thing is, you said it leans out at idle but the pressure is good?

[EsChassisLove]

Yeap. Pressure is good at idle. I unhooked the vacuum and it went to what I had it set at.

This walbro has lasted almost five years....its weird lol

[kojiki88]

damn i got excited till i found out it wasnt wacky wild inflatable flailing arm tube man...:cry:
LMAO :rofl:

I don't think it's the temperature sensor. It sounds more like a dying out pump. Clogged fuel filter??

[EsChassisLove]

Fuel filter was replaced about 12k miles ago. Wouldn't my fuel pressure practically have to stop for it to lean out so bad? 17+AFR.

Could possibly be my STi injectors. Although they've been working fine for the last few months.

[kojiki88]

Not really, just by dropping a few psi it would lean out since the same amount of air is still coming in. Maybe your pump is giving out while driving for a while causing it to send less fuel to the injectors/motor. Maybe the injectors are dirty.