EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
Ya I learned the fake injector thing the hard way with some really expensive diesel injectors. They came in Bosh boxes and even had really convincing laser engravings
The picture I posted I see a #25320.......
From this link it looks like I have "Multech" style, but the part numbers don't look like mine
https://www.wiringspecialties.com/ls...ication-guide/
is it looking like mine aren't real?
Last edited by ovrebo2; 05-03-2024 at 08:45 AM.
-Chris
I'm running a genuine GM C5 fuel filter to convert the later manifold to a return style fuel system. I did that so I didn't have to modify the sending unit, since the sending unit itself is custom and sits in a fuel cell
-Chris
That does not make it a 'return style' system - Corvette filter/regulator functions exactly the same as if the regulator was built into the sending unit inside the tank on a returnless system.
A 'return style' or, more accurately, 'referenced', means there's a vacuum hose that goes from intake manifold to the regulator, so that fuel pressure changes 1:1 with intake vacuum. The two types have to have injector data set up differently.
Post the full 8-digit injector number and also what the fuel pressure is, measured with a mechanical gauge on the rail, and after that getting injector data done right is no big deal.
GM Gen4 Injectors v2.1.xls
ChatGPT is the end result of someone assuming that if they gather up a large enough pile of sh*t it will spontaneously generate a pony.
I smoothed out the intake and exit of the IAC hole. Might have increased the size a little. Drilled a 1/32 hole in the blade and the trucked fired up on its own without me pedaling it. Truck was idling a little high, I assumed because it was now able to reach the high values I'd put in it, so I put stock idle values back in it. I bumped the lower temps by 100
I hooked up the scanner and the truck was now up to an operating temp of 185 and the IAC value was fluttering at ~70. I turned the AC on and it went up to 90 and came down a little. Put the truck in and out of gear and it was now sounding "normal" to me, where before it would kind of stumble if I didn't pedal it.
I don't have a pressure gauge. What do you guys recommend? Do they make one that I could just screw onto the rail schrader?
-Chris
Something like this?
https://www.speedwaymotors.com/FUEL-...PT,273656.html
-Chris
No liquid filled. No permanently mounted on the rail. Needs to have a hose long enough you can put it somewhere you can see it from the driver's seat. It's supposed to be a diagnostic tool, not jewelry for your engine that makes it look snazzy.
GM Gen4 Injectors v2.1.xls
ChatGPT is the end result of someone assuming that if they gather up a large enough pile of sh*t it will spontaneously generate a pony.
Look up “diagnostic fuel pressure gauge”.
https://www.rockauto.com/en/moreinfo.php?pk=8785812 - includes a bunch of crap you will never ever use for anything, but, I'm not aware of a cheaper kit that has only the parts you need.
GM Gen4 Injectors v2.1.xls
ChatGPT is the end result of someone assuming that if they gather up a large enough pile of sh*t it will spontaneously generate a pony.
I own one of the diagnostic style ones. What is it that I'm looking for? Pressure at idle and through the driving range?
I don't know if such a thing exists or if its possible, but what about something that sends a signal that I could pin into the ECU, that way I was able to log it?
-Chris
You need to check the pressure at the rail, because you are DIYing electronic fuel injection. You have changed a whole bunch of stuff and need to: 1, verify that it's working like it should, and 2, find out what the pressure is at idle so that somebody like me can make sure the injector data is correct for what your system runs at.
The Corvette filter/regs are honestly kind of crap. They have a small return port inside, and you can only use up to about a 255LPH pump before it's no longer able to regulate the pressure down to 58 where it's supposed to be. With a big pump like a 450 there could be 80 or 90 PSI in the rail. So it needs to be checked.
GM Gen4 Injectors v2.1.xls
ChatGPT is the end result of someone assuming that if they gather up a large enough pile of sh*t it will spontaneously generate a pony.
you can rent a fuel pressure tester kit from autoozne and oraylies and return it for free.
The ECm/computer from whatever vehicle it came from is tuned for that specific vehicle.
As soon as you start swapping parts and things the entire tune gets thrown off.
So the more information you can provide , via pictures, receipts, what you have done, what has been done, tyupe of exhaust, type of intake, actual injector numbers
MAP sensor numbers, MAF all of that stuff really helps out.
We cant see what you have done, and its hard for us to ask you, becuase you dont know what to say, so it just takes extra time to get all the details out and known.
Your tune and log you posted shows what the engine thinks it is doing, but doenst show anything you have done.
I hope this helps you a bit
Here is a video walk around and shots of the motor
I took a data log on the drive, but I didn't have my wideband hooked up. I'll do that next week and start a new thread since it seems to start up and idle fine now.
Last edited by ovrebo2; 05-03-2024 at 05:39 PM.
-Chris
Just stay with the same thread. Otherwise you will expect us to remember all of the details of your build and changes.