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Leaning out issue past 10 psi E85

ErikS

ErikS

FWD!
Joined
Nov 28, 2007
Location
Lakeway, TX
Howdy. Having a leaning issue under boost with an E85 tune. Tuner thinks its a hardware issue, map is really rich but after 10 psi fueling leans out, starts pulling timing. MBC @ 25 psi. Switched to E85 as 93 gas was getting knock, was hoping it would fix the issue. I can turn the boost down, but target boost with this turbo is 28 psi.

Injector duty cycle is at 70-75%
2.3L B5234FT 9:1 comp
Large plenum custom intake manifold
20G with billet extended compressor wheel
800cc deatchwerks
4.4 rail
3 bar fpr
Quantum 340lph pump
stock fuel lines

Log of issue from TunerPro RT

3Bh5eOHh.png


Any ideas?
 
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got a log of fuel pressure vs rpm/boost? add more duty cycle and see if it fattens up. The amount of change required for actual E85 is quite a lot more than most people (myself initially as well) think, it's not 30%, it's closer to about 70%
 
Don't have a log of fuel pressure versus rpm/boost. Tuner thinks its a fuel delivery issue, but I'm not sure if its pump or injector. I have upgraded voltage to the pump as well. I thought 340 lph was sufficient

1000 cc injectors now? Maybe a 4 bar fpr?
 
Rising rate FPR? You said you upgraded the voltage to the pump, have you measured how large the voltage drop at pump is now?

Had similar issues after changing to E85 with 480lph pump. Running 2 parallel relays with thick wiring and grounding straight to battery cured the issues.
 
8DOM8S8AN said:
Rising rate FPR? You said you upgraded the voltage to the pump, have you measured how large the voltage drop at pump is now?

Had similar issues after changing to E85 with 480lph pump. Running 2 parallel relays with thick wiring and grounding straight to battery cured the issues.
Click to expand...

The 3bar stock fpr is rising rate. Its a single relay to the pump right now with a larger gauge wire and grounded to the frame.

Voltage was good when tested, its only been a 100 miles on the car since.
 
skip the 4 bar. could be fuel filter. I doubt the fuel line size is too small cause iirc the fwd cars have larger ID fuel lines than the rwd ones and I got a lot of love out of the stock fuel system and 1000cc injectors on my old 940.

something to consider. 3bar + 1.5 bar is ~68psi of head pressure on the pump. Not familiar with the quantum brand, is that like a knockoff aeromotive?
there are people complaining about it's ability to keep up on some of the amazon reviews. 4.4 is a return-style rail, correct? I'd try and determine if pressure is actually doing what you think it's doing
 
ErikS said:
Voltage was good when tested,
Click to expand...

What voltage did you measure?

Did you run fuel volume test?

fuel volume test said:
Run a hose from the fuel return to a gallon jug, power the fuel pump for 15 seconds, multiple that the amount of fuel by 240 and you'll have the qt per hour or liter per hour.

This test would be testing the default pressure of your regulator, if you want up the fuel pressure, apply compressor air to the fuel pressure regulator reference point.
Click to expand...

800cc injectors may not be enough for your goal with E85, I know I was running out of injectors with 750cc and E54 near 25psi.

Start boost low at 10 psi, and work the boost way up slowly until the issue is identified and solved.

Your boost control is bad, jumping everywhere.

Is the lime green line your a/f?
 
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linuxman51 said:
skip the 4 bar. could be fuel filter. I doubt the fuel line size is too small cause iirc the fwd cars have larger ID fuel lines than the rwd ones and I got a lot of love out of the stock fuel system and 1000cc injectors on my old 940.

something to consider. 3bar + 1.5 bar is ~68psi of head pressure on the pump. Not familiar with the quantum brand, is that like a knockoff aeromotive?
there are people complaining about it's ability to keep up on some of the amazon reviews. 4.4 is a return-style rail, correct? I'd try and determine if pressure is actually doing what you think it's doing
Click to expand...

The quantum 380 is a aem knockoff that sounds like it comes with gravel in it from the factory
 
ErikS said:
Going to switch the fuel pump to a DW or known E85 capable pump.
Click to expand...

I'd get a gauge on there first to make sure that's what it is. I'd be a little surprised if it wasn't, but a manual fuel pressure test kit from HF would be more than sufficient to check and see if pressure is dropping off in boost. The raw numbers would be nice to know, but the overall trend is what's more important
 
Thanks guys, got some checking to do. Appreciate all the help and direction. Will post back once its figured out.
 
Are you just using stock wiring? If so I'd upgrade it, use the stock wiring to trigger a relay and run voltage off the back of the alternator with a 10g wire to the pump
 
ErikS said:
No, using a larger gauge with a relay.

I think this issue has been identified :oops:.
Click to expand...

No it hasn't.

With 26.4psi at the intake manifold, I ran a 367whp dyno. MS logged my fuel injectors only flowed 132.6 litre/hr at 69.4 psi of fuel pressure. So, if I had a 150 litre/hr pump at 70psi fuel pressure, that would be plenty.

So, unless you run tests, nothing been identified because it's all GUESS work.
 
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ErikS said:
I thought 340 lph was sufficient
Click to expand...

340lhp at what pressure? 3 bar (43.5psi) + 25 psi is 68.5 psi, and I bet the pump capacity is much lower than 340lph.

Edit: yep, hadn't refreshed the page in a while, it's already mentioned.
 
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