Not an LS question, but rather a Holley EFI question?
#1
Thread Starter
Joined: Apr 2012
Posts: 2,021
Likes: 588
From: Ruckersville, VA
Not an LS question, but rather a Holley EFI question?
I figured with all of the Holley talk in here that it would be appropriate to post this question here. If not, mods please delete or move to the right section.
My dad and I have been working on his 1971 Chevelle for about 3 years now, and we could never quite get his 496 dialed in. It's a Dart block, scat rotating assembly, aluminum heads, full roller cam, lifters and rockers and an Edelbrock dual plane intake. For a little background on the motor, it's 9.5:1 to run pump gas and is a mildly aggressive cam. (I can't remember the specs off the top of my head). He has that backed with a TKO600, dual friction clutch and 3.55 12 bolt that is stock other than an Eaton Posi.
Recently, I found a great deal on a complete used Terminator EFI kit and he decided to pull the trigger. For the fuel system we installed the notched Tanks, Inc. EFI tank with the upgraded Walbro 255 pump. -6AN Fittings from front to rear with a 10 micron post filter. Runs up to an adjustable Holley EFI regulator and back through to the tank.
We finally installed it this weekend and after a few hours of tinkering got it up and running but not very well initially. First thing we did was to set up the fuel system right to 43 PSI per the instructions, then went through the Wizards to set it up for his motor. Once it was up and running the car didn't want to idle down past about 1300 rpms? It would run fantastic up over 1500 to WOT, but wouldn't idle down for anything hot or cold. Once it hit about 1300 rpms, it would fall on it's face and the AFR would go from around 13-14 and quickly ramp to 35 and stall. I messed with timing settings, airflow screw on the TB, IAC, and nothing seemed to get the idle down.
What was strange was that when we first got the kit, the fuel regulator was set to 58PSI which I thought was odd since it was off of a running/driving car. I figured why not crank it back up to 58psi and see what it doesn't since it seemed to want more fuel. Almost as soon as we did that, the idle dropped right down where we commanded it to 800 rpms. It idled fantastically now, and all of the AFR's were +/- where they were commanded? I would have assumed that this would have thrown off the injector values. I need to go back to his house to confirm that the injectors are the stock 80lb units that came stock because it's possible that someone swapped them out for larger units or something. That's about the only thing I can think of. Anyone have any other thoughts?
Thanks,
Ryan
My dad and I have been working on his 1971 Chevelle for about 3 years now, and we could never quite get his 496 dialed in. It's a Dart block, scat rotating assembly, aluminum heads, full roller cam, lifters and rockers and an Edelbrock dual plane intake. For a little background on the motor, it's 9.5:1 to run pump gas and is a mildly aggressive cam. (I can't remember the specs off the top of my head). He has that backed with a TKO600, dual friction clutch and 3.55 12 bolt that is stock other than an Eaton Posi.
Recently, I found a great deal on a complete used Terminator EFI kit and he decided to pull the trigger. For the fuel system we installed the notched Tanks, Inc. EFI tank with the upgraded Walbro 255 pump. -6AN Fittings from front to rear with a 10 micron post filter. Runs up to an adjustable Holley EFI regulator and back through to the tank.
We finally installed it this weekend and after a few hours of tinkering got it up and running but not very well initially. First thing we did was to set up the fuel system right to 43 PSI per the instructions, then went through the Wizards to set it up for his motor. Once it was up and running the car didn't want to idle down past about 1300 rpms? It would run fantastic up over 1500 to WOT, but wouldn't idle down for anything hot or cold. Once it hit about 1300 rpms, it would fall on it's face and the AFR would go from around 13-14 and quickly ramp to 35 and stall. I messed with timing settings, airflow screw on the TB, IAC, and nothing seemed to get the idle down.
What was strange was that when we first got the kit, the fuel regulator was set to 58PSI which I thought was odd since it was off of a running/driving car. I figured why not crank it back up to 58psi and see what it doesn't since it seemed to want more fuel. Almost as soon as we did that, the idle dropped right down where we commanded it to 800 rpms. It idled fantastically now, and all of the AFR's were +/- where they were commanded? I would have assumed that this would have thrown off the injector values. I need to go back to his house to confirm that the injectors are the stock 80lb units that came stock because it's possible that someone swapped them out for larger units or something. That's about the only thing I can think of. Anyone have any other thoughts?
Thanks,
Ryan
#4
Do you have any way to view the air/fuel ratio data in real-time??
Second question - do you know that all traces of the previous calibrations are gone?? Myself personally, I probably would have contacted the Holley tech line to find out if there's a way to reset the unit back to factory defaults before starting to dink around with it. (But hell, from what you've described, it might just be fine!)
Second question - do you know that all traces of the previous calibrations are gone?? Myself personally, I probably would have contacted the Holley tech line to find out if there's a way to reset the unit back to factory defaults before starting to dink around with it. (But hell, from what you've described, it might just be fine!)
#5
Thread Starter
Joined: Apr 2012
Posts: 2,021
Likes: 588
From: Ruckersville, VA
Yes, with the 3.5" monitor you can switch to a dashboard that shows both real-time AFR and the commanded AFR and it was usually +/- .2 after we bumped the fuel pressure up.
I'm not sure if there were any leftover calibrations, but I went through the Wizard at the setup menu and I thought that reset the calibrations. For the time being we're just going to run it at the increased fuel pressure as that is what makes it happy.
I'm not sure if there were any leftover calibrations, but I went through the Wizard at the setup menu and I thought that reset the calibrations. For the time being we're just going to run it at the increased fuel pressure as that is what makes it happy.
#6
Some EFI systems do not like dual plane manifolds , I dont know why , just that it is true . No EFI systems like leaks of vacuum or exhaust , I would ask holley about the dual plane , and check the other two , Usually there is a setting for fuel pressure in the configuration , but if it is running well and does not go lean ,,, let her rip .
#7
We dont run anything at 43 psi unless we have to due to it being a huge injector, when it see's vacuum change it could drop in the high 30's and most injectors wont work correctly. If you run 55-58psi it will be easier to tune most of the time especially idle and off idle. If you cant get it tuned with hand held you can always plug in a laptop and adjust the tables to fix any tune issues. TWe tune all of our holley systems with a laptop and software, even the sniper setups.
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#8
We dont run anything at 43 psi unless we have to due to it being a huge injector, when it see's vacuum change it could drop in the high 30's and most injectors wont work correctly. If you run 55-58psi it will be easier to tune most of the time especially idle and off idle. If you cant get it tuned with hand held you can always plug in a laptop and adjust the tables to fix any tune issues. TWe tune all of our holley systems with a laptop and software, even the sniper setups.
Some good info there, thank you! (Going to save that for future reference...)
#11
Joined: Mar 2003
Posts: 10,244
Likes: 1,531
From: The City of Fountains
#12
#13
EDIT I should have said when vacuum decreases not increases.