No secondary regulator, from what I read about the stock fuel rails, they've got a diaphragm regulator built in. So my regulator is bringing the pressure down to ~60 right where the fuel line connects to the rails. Then if i'm not mistaken, the rails themselves drop it to 58.5 internally. If this is wrong, I do have a set of Holley fuel rails I can swap in and then have more ability to control the flow and pressure and even do a true return style fuel line.
A regulator in the rail can't work if there isn't a return line from the rail back to the tank.
Then I'm only regulating to the pressure seen at the connection to the rail (~60psi). These stock rails only have an input, there's nothing leaving the rails going back to the tank. Should I just set my pressure to say 65 psi so there's a little wiggle room? I'd rather it run a touch high vs running low and causing a lean situation.
Pressure in the tune has to match rail pressure. Only wiggle room is on whether your injectors are big enough. Higher pressure can help if they are to small.
What kind of rail has a regulator mounted, but only a single inlet fitting and no return? Kinda figure that if you'd capped something off you would have mentioned it already.
And FYI, you don't really tune EFI by changing the fuel pressure a little this way and that until it runs good. Please stop mentioning things like that.
I must be wrong about the stock rails having a regulator then. I've been working on this build off and on for a few years, and my info is old and I can't remember where I read these things. Apparently there are 2 kinds of rails that came on the truck motors... The first meaningful thing anybody said was that it was running lean so I jumped to making sure the fuel pressure wasn't the issue. I know I can't tune by adjusting the pressure, but I also don't have much experience working on EFI so a lot of this probably sounds like non-sense to you guys who are further along than I am. Sorry if my ideas or suggestions seem off base. Let me get injector 7 swapped out and then I'll run it a while and see if I'm still having STFT numbers in the 20's.
Thanks to everyone for the help and things to look at. I appreciate everyone sharing their knowledge and helping me get my feet wet on this.
He may be mistaking a regulator for a pulse dampener. Looks like the tune is set of for returnless. Have no idea if data is correct or not for you injectors though.Originally Posted by blindsquirrel
A misfire on one cylinder will show up as lean on whichever bank has the misfire, but both banks are pegged lean in the log. Either there is a misfire on B2 also or there is another problem affecting both sides.
Got new injectors today, gonna put 4 in one side tomorrow and I'll log to see what changes, then I'll put the other 4 in the other side and see what happens.
Ok everyone, sorry for the long delay, had a lot going on...
I installed my new injectors and pushed my exhaust out past the transfer case...
***ALSO*** I found a massive vacuum leak from the driver valve cover to the center of the intake (truck manifold). This immediately got my fuel trims to a better level. I am still having some random LTFT that are above 10% though. I was actually able to get out and drive it down the road a bit, so you'll actually see more data than just idling in the yard. I also noticed some MAF codes that I don't understand (P0102/P0103). Could my O2 sensors still be reading wrong based on the codes for those as well? P0030/P0050? I wired those myself based on random info online so they could be wired incorrectly. I can dig up how I have them wired if they look out of whack.
Thanks again for all the help so far... You guys don't know how happy I was to take that first trip around the block today!
Someone mentioned the last tune file was locked, but I don't see that on my end. Let me know if anyone is unable to open the attachments.
Locked for me too. If you accidentally locked it then that means of course it won't be locked for you.
Sorry about that... See if this one is unlocked
6.0_NEW-BASE_TUNE__2-23-2024.hpt
Unlocked.png
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Thanks for the screenshot... I'm getting the same thing on my work computer which i've never used for tuning.. Let me do some research and see what happened to his file.
Figured it out... I had somehow opened the Remote Tuner window and it assigned an ID which locked the file... Sorry for all the confusion
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