4b11slayer

Whats up fam. My car is going lean amd dont know what to do.

Fp red
E85
S2
Head studs.

I punch it in 2nd gear and spool up is 12.8 then it drops to 10.8 and upnto 13.4

I dont wana blow my motor. Please help


Oh also wally 450 1450 blue max
Stock fpr,rail,lines. No return mods. Not rewired to my knowledge either.

There is a video link.

4b11slayer

4b11slayer

Guys I have some logs I would like to upload but I am unsure how to.

Please help.

RightSaid fred

Your fuel pressure is out of control

4b11slayer

I measured 40 ish at idle with vaccum line connected to fpr.

RightSaid fred

It's still out of control.

You need to take measurements under load.

Besides, it should be 33 PSI not 40 PSI.
43 with the vac line off.

4b11slayer

If its supposed to be 33 idle and im at 40 don't you think id be rich?

RightSaid fred

No, it goes lean when the fuel usage increases because there's then less flow through the regulator.

That's why you test under load as well as at idle.

At 40 PSI at idle with the vac hose ON........that's 50 PSI base pressure from a 43 PSI reg.


Which is what everyone gets when the pump is too big.

4b11slayer

I heared there is a return line mod.
Have to drill something in the pump hangar.

Anybinput guys? Walbro 450

RightSaid fred

It's the regulator.

You'll know this when you remove the return line from the reg........flow it into a suitable container while measuring the pressure at idle.

4b11slayer

I removed my fuel pump hangar to double check things
, added 2 new thicker o rings to my pump outlet and drilled out my return line siphon to 9/64. I havent done a pull yet.

Target afr is 12.5
Fuel map is. 9.5 were im going lean
Actual afr is. 13.5

What do i need to do to have a closer actual afr to my fuel table?

Injector scaling? Or maf scaling?

ExViTermini

iTrader: (25)

What is fuel pressure when it goes lean? Don't worry about getting the fuel tables to match real world afr's, you'll pull your hair out trying. I will say having 9.5 in the tables and seeing 13+ afr, something is awry. I would say that you should check pressures under load.

you can post your fuel map, sd settings, injector base value and it may lend some more insight, but I would say you definitely have a fuel pressure problem. The return line mods will have nothing to do with your lean problems.

4b11slayer

Thanks for the reply, im on maf. 96530706. .
Return line mod had no difference.
I removed fuel pump hangar to re inspect, nothing caught my eye. I followed diy thread on here for wally 450.

Cut top barb,add 2 orings and reuse oem pump feed rubber.

Used metal clamp to hold pump in place.

mines5

Have you ever considered your 1450s to be part of the problem ? I experienced a similar situation when i was on MAF 1450s on pump gas but it never leaned into 13 AFRs.

4b11slayer

Sir, i doubt its the fuel injectors. Isnt fic the best brand for injectors? .

Ive read the 450 wally diy thread here and some say they can lose pressure from hangar.

What about a rewire? Or maybe a faulty relay? For higher loads?

I can punch it and afr does what i want it to do, then im guessing around 20 psi or more it leans.

I can part throttle it to 6k rpm with steady afr. But wot aint having it.