Question about correcting bpw for high fuel pressure.
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Question about correcting bpw for high fuel pressure.
Is correcting the base pulse width the same for every ECU?
Or are there different equations for different computers?
I understandthat the pw needs to be corrected for higher fuel pressure but where in the bin file do you do this?
Or are there different equations for different computers?
I understandthat the pw needs to be corrected for higher fuel pressure but where in the bin file do you do this?
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Re: Question about correcting bpw for high fuel pressure.
-- Joe
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Re: Question about correcting bpw for high fuel pressure.
Ecu is 7747 mask 42
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Re: Question about correcting bpw for high fuel pressure.
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Re: Question about correcting bpw for high fuel pressure.
Aahh.. I seeee... no. Lol I keep reading about a constants menu, but nothing in tuner pro do I see about constants. Haha are these constants scalars? Flags? In the tables? A drop down menu like the data monitors?
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Re: Question about correcting bpw for high fuel pressure.
Can someone direct me to a source where I can all I need to know about the values that need to be changed in the ecu mask 42, for increased fuel pressure, and what exactly needs to be fined tuned so I can at least start tuning for idle....
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Re: Question about correcting bpw for high fuel pressure.
The engine will make somewhere between 350-400ish horsepower. At this point I have no idea.to many others saying different things. Which equation do I use for the constant value for fuel pressure? I have no idea what fuel pressure to use either. My system can go up until 43psi.
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Question about correcting bpw for high fuel pressure.
The engine will make somewhere between 350-400ish horsepower. At this point I have no idea.to many others saying different things. Which equation do I use for the constant value for fuel pressure? I have no idea what fuel pressure to use either. My system can go up until 43psi.
I use Tunercat, so I don't know what the layout is like for $42 in tunerpro.
You should probably read some of the stickys on tuning before you dive in. Basically, you are going to set your base pulse and then adjust your VE table(s) until your BLM's are in check, and then adjust your PE fuel until your WOT gives a good AFR, then you can play with timing.
-- Joe
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Re: Question about correcting bpw for high fuel pressure.
Okay so basically, tune the ve based on what I see from the blm data at certain cells. But does spark effect how fuel is being read? I've also read that you can force open loop for idle, but no idea how to do that. Or even sync vs async fueling. What do those follow under??
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Question about correcting bpw for high fuel pressure.
Okay so basically, tune the ve based on what I see from the blm data at certain cells. But does spark effect how fuel is being read? I've also read that you can force open loop for idle, but no idea how to do that. Or even sync vs async fueling. What do those follow under??
Spark and fuel go hand in hand, but the stock advance curve should be fine. Dial in your fuel map and then work on spark.
Don't worry about sync vs async fueling.
-- Joe
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Car: 89 Chevrolet c1500 Cheyenne fleetsi
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Re: Question about correcting bpw for high fuel pressure.
Well I am worried about those different types of fueling. Since I'm going to be running such an insane about of fuel pressure. Also with my first datalog.... the spark advance was reading waaaaaayyyyyyy high, like 80+ at idle, what could cause this???
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Re: Question about correcting bpw for high fuel pressure.
Another thing is that my pw is reading 200-800% at IDLE. I'm going to need to tune the VE extreme well for this bigger cam,ZZ4. Im getting around 17 in hg on my mechanical gauge.
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Car: 89 Chevrolet c1500 Cheyenne fleetsi
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Re: Question about correcting bpw for high fuel pressure.
I did have to fix a vacuum leak on both intake gaskets. Using an air gap with vortec style procomp heads ports are different sizes a hahaha butchery! So I replaced the gaskets and the walls are thin but I think they are doing the job, I used a bit of gasket maker to seal them in this time....
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Car: '88 Formula, '94 Corvette, '95 Bird
Engine: LC9, 355" LT1, LT1
Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Question about correcting bpw for high fuel pressure.
If this is a hot-rod, have you considered an aftermarket system? I've heard a lot of good things about the newer Holley stuff, and the learning curve isn't too much.
-- Joe
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Car: 89 Chevrolet c1500 Cheyenne fleetsi
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Transmission: 700r4
Axle/Gears: 2.73
Re: Question about correcting bpw for high fuel pressure.
I haaave, only problem. I'm 23 freshly fired from walmart for attendance. So no more money right now. Hahaha
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Re: Question about correcting bpw for high fuel pressure.
I do have the Holley 502-6 670cfm projection though. Still a little unsure of the injector size, do to Holley not picking up the phone and difference of opinions on the Net. Either 65lbs at 12psi or 85lb at 12psi. No. Idea.
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Re: Question about correcting bpw for high fuel pressure.
I did fail to mention that I had like it around 6 degrees advanced at the dizzy, with no accommodation in the chip, so that could have something to do with it..
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Re: Question about correcting bpw for high fuel pressure.
Just got off the phone with Holley. They are 65lbs at 12psi. And they said can not run then safely over 25psi. Well that sucks, cause I needed them to run at 43psi hahaha. Anyone want to buy all my tuning gear and TBI??
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Car: '88 Formula, '94 Corvette, '95 Bird
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Re: Question about correcting bpw for high fuel pressure.
As far as your spark advance, 80 is just crazy. I don't know why it would be reporting that. Nothing in the calibration, even the steepest decel burn off is that high. Something is not right.
-- Joe
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Re: Question about correcting bpw for high fuel pressure.
Have you considered the military? They will pay for your college, and pay for you to go to school (if you are deployed). There is nothing more rewarding than service to your country.
As far as your spark advance, 80 is just crazy. I don't know why it would be reporting that. Nothing in the calibration, even the steepest decel burn off is that high. Something is not right.
-- Joe
As far as your spark advance, 80 is just crazy. I don't know why it would be reporting that. Nothing in the calibration, even the steepest decel burn off is that high. Something is not right.
-- Joe
Yeah I've tried the military, I have a long history of asthma, so that is that......
As for tuning this now.... Idk Holley just said I can't safely run their injectors at 43psi. Over 25psi. I don't have a 4 brrl tbi. So I think I'm just going to have to sell all this stuff I purchased. $1045. For this. My sweet luck. And lack of know how.
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Car: '88 Formula, '94 Corvette, '95 Bird
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Transmission: T5, Zf6, 4L60E
Axle/Gears: 3.42, Dana44 3.45, 3.23
Re: Question about correcting bpw for high fuel pressure.
Yeah I've tried the military, I have a long history of asthma, so that is that......
As for tuning this now.... Idk Holley just said I can't safely run their injectors at 43psi. Over 25psi. I don't have a 4 brrl tbi. So I think I'm just going to have to sell all this stuff I purchased. $1045. For this. My sweet luck. And lack of know how.
As for tuning this now.... Idk Holley just said I can't safely run their injectors at 43psi. Over 25psi. I don't have a 4 brrl tbi. So I think I'm just going to have to sell all this stuff I purchased. $1045. For this. My sweet luck. And lack of know how.
I suspect your reason for wanting higher fuel pressure is because the injectors are too small for the application? In theory the 65# injectors only support about 250hp.
There is a lot of little off the shelf, self-tuning TBI units on the market now, many under $2,000. You won't find much info on this forum, but if you hang out in Corvette forum where a lot of guys do EFI swaps on older vehicles, or Yellowbullet you will find the information you need.
-- Joe
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