dfi gurus - no injector grounds/pulse
#1
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Car: 1987 Camaro IROC Z28
Engine: 355
Transmission: 1994 T56
Axle/Gears: BW 3.27 (stock)
dfi gurus - no injector grounds/pulse
I have a DFI 6 setup.
i'm trying to start my iroc for the first time since fall, and the injectors don't seem to be firing. I didn't touch anything since it ran last and i loaded a known working program in, and the injectors refuse to fire.
I did some testing and found that the injectors are not grounding. i see 12v on each pin in the injector connectors when grounded. but if i go into the monitoring control, it does show that the computer is trying to assign it a map cell - i am getting pulse width numbers to show up on the screen as it cranks.
the thing has been kind of stubborn to start before if it sat a while, I've had to load the program in several times before it took, or crank for a full minute before the injectors fired, but it usually would be running in 5-10 minutes of tinkering. no such luck this time around.
suggestions? i tried obvious stuff, and there seems to be appropriate power inputs for the red (connected direct to battery +), black and black/purple (connected direct to battery -), and the pink to switched power.
one other thing i noticed is that i had to hotwire my fuel pump to come on. when it's wired through a relay using the signal output, it goes on for a second, and then stops. then no more signal.
think it's the computer? does anyone have a good reference schematic or a thorough explanation of how things work? I'm wondering what circumstances with bad sensor ranges or anything like that might cause the injectors to not receive ground signal.
I'm gonna keep tinkering tonight, but maybe i'm missing something obvious?
i'm trying to start my iroc for the first time since fall, and the injectors don't seem to be firing. I didn't touch anything since it ran last and i loaded a known working program in, and the injectors refuse to fire.
I did some testing and found that the injectors are not grounding. i see 12v on each pin in the injector connectors when grounded. but if i go into the monitoring control, it does show that the computer is trying to assign it a map cell - i am getting pulse width numbers to show up on the screen as it cranks.
the thing has been kind of stubborn to start before if it sat a while, I've had to load the program in several times before it took, or crank for a full minute before the injectors fired, but it usually would be running in 5-10 minutes of tinkering. no such luck this time around.
suggestions? i tried obvious stuff, and there seems to be appropriate power inputs for the red (connected direct to battery +), black and black/purple (connected direct to battery -), and the pink to switched power.
one other thing i noticed is that i had to hotwire my fuel pump to come on. when it's wired through a relay using the signal output, it goes on for a second, and then stops. then no more signal.
think it's the computer? does anyone have a good reference schematic or a thorough explanation of how things work? I'm wondering what circumstances with bad sensor ranges or anything like that might cause the injectors to not receive ground signal.
I'm gonna keep tinkering tonight, but maybe i'm missing something obvious?
#2
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Car: GTP
Engine: L67
When looking at the view screen, do you see RPM when you are cranking? The computer won't even try to fire the injectors unless it is reading a (good) crank input signal -- indicated by an RPM reading on the PC screen.
Are you getting any spark output? If you are getting spark, but not the fuel, you may have a box problem. If you're not getting either, then I'd look hard at the crank signal.
Are you getting any spark output? If you are getting spark, but not the fuel, you may have a box problem. If you're not getting either, then I'd look hard at the crank signal.
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Car: 1987 Camaro IROC Z28
Engine: 355
Transmission: 1994 T56
Axle/Gears: BW 3.27 (stock)
i had no reason to suspect them because they were fine a few months before when the car was parked and it ran ok on the dfi setup.
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