No injection into cylinders
02-07-2017, 12:37 AM
#1
No injection into cylinders
I'm getting good fuel pressure on rail car starts but stalls , i have power to both wires going to top of injectors when the key is on is that correct? For this car 1985 c4
02-07-2017, 03:40 AM
#2
Race Director
You need to have DRPs (Distributor Reference Pulses) from the ignition module inside the distributor to the ECM so it can pulse the injectors. This is needed so the ECM can synchronize the pulsing of the injectors to the rotation of the engine. If the fuel pump relay is being energized then the DRPs are present.
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Todd Osgood (02-07-2017)
02-07-2017, 09:02 AM
#5
Sort of. The injectors are supplied with 12 volts through the INJ1 and INJ2 fuses. If the injectors are not being pulsed there will also be 12 volts on the other wire. The ECM applies ground to the light blue and light green wires to pulse the injectors.
You need to have DRPs (Distributor Reference Pulses) from the ignition module inside the distributor to the ECM so it can pulse the injectors. This is needed so the ECM can synchronize the pulsing of the injectors to the rotation of the engine. If the fuel pump relay is being energized then the DRPs are present.
You need to have DRPs (Distributor Reference Pulses) from the ignition module inside the distributor to the ECM so it can pulse the injectors. This is needed so the ECM can synchronize the pulsing of the injectors to the rotation of the engine. If the fuel pump relay is being energized then the DRPs are present.
02-07-2017, 09:31 AM
#6
Are your fuses good? Go borrow a noid light from the parts store and let us know. They can test the ICM as well. I would pull and clean the connection to the dizzy first.
Last edited by antfarmer2; 02-07-2017 at 09:36 AM.
02-07-2017, 11:46 AM
#9
Race Director
You need to back up and start with the basics. Your car stalls out. A motor needs spark and fuel to run. Pull a plug or two after it stalls out. Is the plug wet with fuel? If so, you have fuel and no spark. If the plug is dry, see if you get spark when you crank. This will get you on the right track instead of throwing the kitchen sink at the problem. If you can get a hold of the service manual, there are flow charts that will guide you systematically to solutions to problems.
02-07-2017, 11:50 AM
#10
Burning Brakes
What has you convinced it's a lack of fuel causing the stall? Stall at idle? At higher revs?
02-07-2017, 03:46 PM
#11
Melting Slicks
Sounds like the cold start injector and nothing else. Check the injectors for ohms to see if you are overloading the drivers. They should be 14 ohms +-2 if you have some that are low leave them unplugged and see if it runs on the cylinders that are ok.
02-07-2017, 04:53 PM
#12
Okay the distributor connections are clean the ICM is good and the Noid light still don't pulse .
So so does that bring it down to a new ECM or my Vats system is not letting the injectors fire?
Because I just put a new steering column in the vehicle and I'm not sure if the new barrel and pellet key match the Vats system is that where I should go first? Because the starter is already bypassed.
Thank you in advance , Todd.
So so does that bring it down to a new ECM or my Vats system is not letting the injectors fire?
Because I just put a new steering column in the vehicle and I'm not sure if the new barrel and pellet key match the Vats system is that where I should go first? Because the starter is already bypassed.
Thank you in advance , Todd.
02-07-2017, 05:16 PM
#13
Okay will check the ohms and will report back as soon as possible and thank you for your input
02-07-2017, 06:02 PM
#14
Drifting
'85s don't have VATS, so don't worry about any of that.
02-07-2017, 07:08 PM
#15
Have you checked the two injector fuses yet? If good crank it and have someone smack the ECM at the same time.
02-08-2017, 12:29 AM
#17
Team Owner
Does it stall at idle or at higher revs like you asked. Also, does it restart? Is it a random stall or does it happen after a certain number of minutes? Any way to reproduce the stall?
02-12-2017, 05:10 PM
#18
Safety Car
Okay the distributor connections are clean the ICM is good and the Noid light still don't pulse .
So so does that bring it down to a new ECM or my Vats system is not letting the injectors fire?
Because I just put a new steering column in the vehicle and I'm not sure if the new barrel and pellet key match the Vats system is that where I should go first? Because the starter is already bypassed.
Thank you in advance , Todd.
So so does that bring it down to a new ECM or my Vats system is not letting the injectors fire?
Because I just put a new steering column in the vehicle and I'm not sure if the new barrel and pellet key match the Vats system is that where I should go first? Because the starter is already bypassed.
Thank you in advance , Todd.
ECM has to have inputs from distributor to supply the pulse.
The ECM could also be shutting down the injectors if it sees too much currently flow if one or many of the injectors are shorted or starting to short. Does it flash at all during cranking? Does it flash at first and then stop?
You REALLY need a service manual and a multi-meter. Its NOT an option if you want an accurate diagnosis.
Clean connections-OK, but your dealing with electronic components. Do you have power, ground, signals where you are supposed to? Are the signals good?
There is a lot of bad info and half truths in this thread.
The bottom line is if you don't have injector pulse, you need to fix that first. Does it flash on BOTH banks or just one or what?