Lean at wot

TireFryer

The new kid..
So i took the car for a drive today. It has a hood mounted gauge and it's set at 42 psi line ON. If i drive it normally it runs nice and doesn't sputter or spit. But if i give it some gas to get going over a hill or something, it goes lean instantly. I gave it some juice to around 1-2 psi and I would have kept going but the Scanmaster G was showing me anywhere from 13.5 to 17.2:1 This scared me so I just drove it easy the rest of the way. I have a 6.1 PLX wideband chip and im running alky (i dont think it turned on at 2 psi) And a dw300 fuel pump and AFPR from accufab. I also have 80# injectors. it Cruises around 13-15:1 and runs good. It's a brand new chip and wideband sensor. The chip is programmed for a wot afr of 10.8:1 could it be because i never got into the "WOT" section of the chip? Do i have to get to a certain TPS volt to kick in "WOT" afr setting? I just rebuilt this engine so o would love to not blow it up... Any advice is amazing!

Thanks!
 

Mr.Spool

Well-Known Member
it Cruises around 13-15:1 and runs good. It's a brand new chip and wideband sensor. The chip is programmed for a wot afr of 10.8:1
you should see the afr from cruise range head to the commanded 10.8afr,if the fuel system and computer are working correctly.i couldnt read your file.but i fuel pressure needs to rise 1to1 with boost and you need to really see alky pressure as well,if you cant make sure your going red to green.
 

Mr.Spool

Well-Known Member
It has a hood mounted gauge and it's set at 42 psi line ON. If i drive it normally it runs nice and doesn't sputter or spit. But if i give it some gas to get going over a hill or something, it goes lean instantly.
if the fuel pressure is not going 1to1 with boost,you need to start troubleshooting it dont go wot
 

MikeS

Active Member
I couldn't view the file either. In addition to checking what the fuel pressure is doing, switch the scan master over to voltage and see what it is doing. You have a Hotwire to the fuel pump, but do you have a good ground wire for the fuel pump?
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
WB doesn't take over to 70 percent throttle and you're nowhere near that so you're running off the NB. Battery voltage is fine. WB is 14-15:1...and you say you have it set to 10.8:1
 

TireFryer

The new kid..
you should see the afr from cruise range head to the commanded 10.8afr,if the fuel system and computer are working correctly.i couldnt read your file.but i fuel pressure needs to rise 1to1 with boost and you need to really see alky pressure as well,if you cant make sure your going red to green.
I never got into enough boost to even activate the alky, should it go from red to green while priming it with the test button? Because we just put a nozzle on it and sprayed it into the tank to check for leaks... the pump was at 8 and it never went from red to green... even after letting it run for 10-15 seconds
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
I never got into enough boost to even activate the alky, should it go from red to green while priming it with the test button? Because we just put a nozzle on it and sprayed it into the tank to check for leaks... the pump was at 8 and it never went from red to green... even after letting it run for 10-15 seconds
Hit the test button and it'll bog the engine and pretty much stall it out. You're not into boost so I wouldn't expect he light to come on. How old is the NB sensor. If the sensor isn't sending correct data back to the ECM then all hell will break loose. As the other gents have said, adjust your FP correctly.
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
Contact Eric here on the board and ask him for his opinion on what he sees on your file.
 

TireFryer

The new kid..
Hit the test button and it'll bog the engine and pretty much stall it out. You're not into boost so I wouldn't expect he light to come on. How old is the NB sensor. If the sensor isn't sending correct data back to the ECM then all hell will break loose. As the other gents have said, adjust your FP correctly.
I have no clue... for all i know its stock the oem sensor...
 

Mr.Spool

Well-Known Member
I never got into enough boost to even activate the alky, should it go from red to green while priming it with the test button? Because we just put a nozzle on it and sprayed it into the tank to check for leaks... the pump was at 8 and it never went from red to green... even after letting it run for 10-15 seconds
ok,it goes green around 40/50psi depending on setting and reads off the map so you need to see boost.
 

Ttype6

Well-Known Member
As soon as you open the throttle,the fuel pressure should rise. When the throttle returns to idle,fuel pressure should fall.
I have no clue... for all i know its stock the oem sensor...

After setting the fuel pressure to 42 with the line off,the pressure should fall 5 or 6 pounds when you hook the line back up. Does it?
 

TireFryer

The new kid..
The fuel pressure even with the line off i cant get below 42 psi so i do believe I am one of the unlucky few that needs a return line made... I have -6 hose that I'll be having made on monday and running a new return line. The pressure stays right around 42-43 line on or off, It lowers maybe 1 psi but that's it.
 
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