Hi mods, not sure where to post this but please feel free to move it. thanks.
TAKE NOTE: i'm not saying you should change the fuel pump right then and there..this is a hit or miss thing..

parts:
now OEM fmic
depot UICP
Nisei LICP
now ETS ext o2 dump
megan catback
i already have the blue relay

anyway, to cut the first part of the story short, i was leaning out so bad at WOT at peak boost. it was a good thing i was logging at that time. my tune was all good a week before that, just wanted to fine tune the car for the winter. i was shocked that i was suddenly knocking. i checked the timing and boost, it was supposed to be fine. i checked the AFR's it was 12.5++ (btw i'm on 93) going to 5krpms. i immediately stopped and let it idle a few mins and all seems to be good. i then logged again and same thing. i changed to 3 relays, (horn, head light, and my old OEM black relay) same thing. i used different fpr hoses and same thing. i checked my IDC's and they're way off.

i knew it was fuel supply, i didn't have aftermarket fpr to check fuel pressure, and don't also know how to check the voltage going to the pump. so going e85 route in the future, i thought of buying the MAP walbro 255 kit.

after installing it, my AFRs are back to normal. IDC's are back to normal. i'm still observing it. i always use either exxon/chevron/texaco 93. i'll try to take pics when i have time. it looks the OEM fuel filter looks dirty, but i don't it's enough to block (can't confirm though).

well, i know i'm the first that has this issue with basic bolt ons. so i guess with EVO x fuel pumps it's a hit or miss too. i'd strongly recommend now to have fuel pumps with just basic bolt ons. but of course that's up to you

My stock pump was fine with normal use, but when fuel temps rose the car would start leaning out. That's when I went to a Walbro. Stock turbo with bolt-ons at the time; 93-octane.

yea i agree with you about the fuel temps..but for my mods and i was actually tuning it down..it shouldn't be needing the new pump at that rate..at least for the x that is..

Is this something that happens only to cars with bolt ons using a stock FP, or can it happen to a bone stock car? Sounds like one of the first things I should change out is my fuel pump.

The stock fuel pump would be fine for the stock evo otherwise it wouldnt be on there, but from what I've read here, I'd look into getting a new one anyways.

a bone stock car shouldn't be needing a pump.. i'd recommend it though if you have the basic bolt on parts just to be on the safe side..the stock pump should suffice but you'll never know when the "hit or miss thing" will take place..

TAKE NOTE: i'm not saying you should change it right then and there..this is a hit or miss thing..

The stock pump is perfectly fine and safe for a stock or lightly modded Evo. I didn't have issues until I upgraded my manifolds and throttle body.

And what aboiut a lightly modded car with a built block, TBE, 3 port, Boomba rail, AFPR, and ID1000's. How ould the stock pump fare? Also, what should the fuel pressure be at the rail? This is what I have and a stock pump.

is the "AFPR" aftermarket FPR? if it is, are you increasing the fuel pressure basically to supply fuel for that injectors? what gas? i can't say for sure how reliable the OEM fuel pump is with increasing the pressure.

but if you ask me, i'd change my fuel pump (my .02). you can wait for some more input here as i'm in no position to have experience what other builders/tuners have experienced.

Are you sure your fuel pressure hose didn't just pop off. I have logged all 3 of my Evo X's and not one had an issue till I upgraded the turbo on the last one. Stock fuel pump with the Cobb stage 2 and all bolt ons and was still reading in the low 11's at redline. there maybe a leak somewhere in your vaccum system.

^^ yes i did check it..and swapped more than 3 hoses that i have. i placed that in my first post.
also i think this is a HIT OR MISS thing. not saying all are the same.

ID1000s and a BBX lite, 26psi. Stock pump, zero issues.

Adjustable FPR. I ask this question because the base idle pressure is set to 54psi and I have no idea if the stock pump can support this base pressure and then there is the rising rate as well.

I agree about a new pump.

I bought the car this way so I am still sorting some stuff out.

Any thoughts Kracka?

^ jeezus! 54 psi? O_o seems awfully high. I was thinking 40's
I've been running a precision 6031e, 1000cc injectors and full bolt ons and havent had a problem with the stock pump. i do have an afpr as well like jordantii to keep the base fuel pressure up at idle so i dont run lean.

thanks for the info. ill keep an eye on this. id rather be proactive and replace a pump rather than reactive to fix the car.