Going lean @WOT
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Going lean @WOT Ok so maybe u guys can help me diagnose an issue. Car has a cammed ly6/whipple 2.9 @10-11 lbs boost. Ractronix FP 450lph 65 lb injectors , -8 to rail -6 return. Hot wire kit etc.. found out it was advanced a little too much for pump. 24* pulled it back to 18* max. Been messing with VE % to fix afr . Now it goes lean @WOT . Was @ 92% . Went as high as 97% still lean. Fuel pump fuse was melted so I changed holder/fuse still same deal. I'm thinking fuel pump is getting weaker. I ordered another 450 . Could there be something in tune holding afr back? Mast m-90 ecm. Speed density tuned .
Is this in your Yugo /LS swap, or?
No mention of actual fuel psi. What is it at max boost?
Regulator referenced?
Bad ground to pump?
Lots of things to check before throwing parts at it.
Data logs?
No mention of actual fuel psi. What is it at max boost?
Regulator referenced?
Bad ground to pump?
Lots of things to check before throwing parts at it.
Data logs?
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83 cutlass . Fuel pressure set @ 65 lbs
Reg is after rails. Not boost referenced. The grounds look good . Grounded to chassis prob 4 ft from main ground( batt is in trunk) it was working fine till I backed timing down.
Reg is after rails. Not boost referenced. The grounds look good . Grounded to chassis prob 4 ft from main ground( batt is in trunk) it was working fine till I backed timing down.
Move the timing back up a little? I remember a thread a few days ago with timing affecting the afr. There was a wealth of info in that thread but its not on the first page now and im lazy.. Lol
Nevermind. I found that thread and you started that thread too. Lol my bad
So its still going lean. Im trying to remember. You watched a fuel psi gauge while it was going lean and the psi stayed steady correct? Or i may have dreamed that
Isnt 18* still high for 10psi? Most cars i see are running sub 15* at 10psi
So its still going lean. Im trying to remember. You watched a fuel psi gauge while it was going lean and the psi stayed steady correct? Or i may have dreamed that
Isnt 18* still high for 10psi? Most cars i see are running sub 15* at 10psi
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Nevermind. I found that thread and you started that thread too. Lol my bad
So its still going lean. Im trying to remember. You watched a fuel psi gauge while it was going lean and the psi stayed steady correct? Or i may have dreamed that
Isnt 18* still high for 10psi? Most cars i see are running sub 15* at 10psi
So its still going lean. Im trying to remember. You watched a fuel psi gauge while it was going lean and the psi stayed steady correct? Or i may have dreamed that
Isnt 18* still high for 10psi? Most cars i see are running sub 15* at 10psi
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Without a boost referenced regulator when you're at 10lbs of boost your pressure gauge may read the same but the engine is seeing less fuel because the injector is seeing 10lbs of head pressure. So if your base pressure is for example 55lbs with no boost then at 10lbs of boost your injector will only flow what it's rated for at 45lbs of pressure.
Thread Starter
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Thread Starter
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Without a boost referenced regulator when you're at 10lbs of boost your pressure gauge may read the same but the engine is seeing less fuel because the injector is seeing 10lbs of head pressure. So if your base pressure is for example 55lbs with no boost then at 10lbs of boost your injector will only flow what it's rated for at 45lbs of pressure.
Im pretty sure the wideband is smoked. I ordered a new one so we will see. I totally get what your saying about the injectors . How would you set it up? I think mast wanted 65lbs of fuel pressure because the fast 65lb are rated @58psi.
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The fuel system is as follows. Racetronix hanger w/Walbro 450, -8 to engine bay ,y fitting then -6 to each side of rails. -6 to reg, -6 return I have an aeromotive boost ref reg but no vacuum line hooked up
I could hook it up pretty easy, but what to set fuel presssure to? Could I leave it at 65 and hook up line?
I could hook it up pretty easy, but what to set fuel presssure to? Could I leave it at 65 and hook up line?
Edit: you're speed density tuned so the computer doesn't calculate fuel based on a maf so I would think you would also need a referenced regulator.
Last edited by LLLosingit; Jun 4, 2017 at 10:00 PM.
am I reading this right u say u are around 97% at wot in your VE table? if so yes I woud think u are lean. Stock NA ve tables have fueling around that area. What I would do is go back to a stock VE table. Thin add 15% to everything in the boost region. give it a try and see what happins. If still lean hit it with another 5% and so forth. if fueling doesn't try and go rich u have a fuel supply problem. u need a fuel pressure gauge on it asap.
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It was working fine until recently. Been beating on it since last summer. This all started when I got the meth kit and started messing with timing and afr. There is a boost page in tuning software. I suspect it adds fuel to VE