sr20 leaning out--what are my options?

[kooltacos]

so as some of you know I have just finished an sr swap into a 95.

I have aem tru boost ebc and stock s13 sr with a t25, and aem wideband.

I am running lean on stock boost, around 8 psi. about 14:1 and 12 psi about 15.5:1. I am not having any driveability problems, the car hauls pretty good at 12psi.

I have stock injectors and stock fuel pump. I have not checked fuel pressure.

If I just drop in some 500cc injectors what should I expect untuned? I just want to run the 12psi with a safe afr. Whats the cheapest way to go here?

[MR.chris]

That sounds bad. I'd check for boost leaks first.

[kooltacos]

this may be a dumb ? but how does a boost leak cause a lean condition? wouldn't an air leak cause a rich condition? anyway I have already tested for leaks with my homemade pvc boost pipe tester, and there were no leaks. Should stock boost on stock tune be closer to an 11-12 afr? I do have a 200K+ mile fuel pump running this crap

[PyR0NiAk]

Upgrade to a walbro 255. That would be my first guess. I remember reading rumors about them causing issues with the stock FPRs so it may be a good time to upgrade your FPR to an adjustable one with a gauge while you're at it. I would definitely be making a point to stay out of boost until I got this issue fixed.

[Second Shadow]

I would get a fuel gauge first, they're cheap and easy to install and will tell you if you have a fuel pressure problem. also, check for vacuum leaks after the maf but before the turbo. a leak there will allow air to get into your intake system without going through the maf first, making you run lean.

[kooltacos]

I would get a fuel gauge first, they're cheap and easy to install and will tell you if you have a fuel pressure problem. also, check for vacuum leaks after the maf but before the turbo. a leak there will allow air to get into your intake system without going through the maf first, making you run lean.

I ordered a pressure gauge today, The only thing I have connected between my maf and turbo is the vent tube from the valve cover. I sprayed everything down with carb cleaner to check for leaks, I did not find and leaks....

[Second Shadow]

are you sure? most intake pipes in addition to the port for the line off the valve cover(as they are based on the stock one) have a small nipple on top and a second larger port hidden on the bottom for the stock rercirc valve. this is typically capped off if you have an after market bov.

I only bring this up because if you didn't already know it was there that second larger port is next to invisible. ( it happened to me).

[PyR0NiAk]

Upgrading to a 255 is something that honestly should be done when you do your motor swap, so now would definitely be a good time to do it, as I stated before. They're like $90 shipped from a nico sponsor. Check the advertiser's market. And if you're super strapped for cash, Enjuku sells the isis version even cheaper. As far as the aftermarket fpr, I got my used one with a gauge for $20, so once again NOT expensive. These are all things that are smart to have anyway.

I'm not saying this because I think what shadow is saying is wrong. He's 100% correct in how that COULD be causing your problem. I just think it's unlikely considering you even said you were running on a 200k mile fuel pump.

[kooltacos]

are you sure? most intake pipes in addition to the port for the line off the valve cover(as they are based on the stock one) have a small nipple on top and a second larger port hidden on the bottom for the stock rercirc valve. this is typically capped off if you have an after market bov.

I only bring this up because if you didn't already know it was there that second larger port is next to invisible. ( it happened to me).

yeah its capped, my bov is venting

[kooltacos]

Upgrading to a 255 is something that honestly should be done when you do your motor swap, so now would definitely be a good time to do it, as I stated before. They're like $90 shipped from a nico sponsor. Check the advertiser's market. And if you're super strapped for cash, Enjuku sells the isis version even cheaper. As far as the aftermarket fpr, I got my used one with a gauge for $20, so once again NOT expensive. These are all things that are smart to have anyway.

I'm not saying this because I think what shadow is saying is wrong. He's 100% correct in how that COULD be causing your problem. I just think it's unlikely considering you even said you were running on a 200k mile fuel pump.

yeah I ordered a 255lph walbro today too. do you have one of those universal inline fprs? or do you have something that bolts to the factory rail?

[PyR0NiAk]

I got an inline FPR. I had no choice considering I'm running an aftermarket rail. If you end up with a universal and you need an adapter kit, let me know and I'll try to send you the adapter kit that came with mine, seeing as how I don't need it.

[kooltacos]

hey pyro, I'll be glad to take that adapter. I installed my fuel pressure gauge today. it runs around 50 psi, but dips to 40 under throttle. I am just guessing my pump cant keep up.

[PyR0NiAk]

Called that one didn't I? Weird thing is, the only way you should be in the 40s for your fuel pressure is if the vacuum source is unhooked.


Either way, I just went out to the garage and grabbed it for you. Amazingly, I knew exactly where it was in my pile of spare parts.

PM me your address and I'll try to get it out for you tomorrow. Unfortunately, I get off work every day between 4:30 and 5, and the post office here on base closes at 4:15 so I'll have to try and get it out during lunch. If nothing else, I'll get the wife to ship it out for you.