Injectors are NOT firing
08-20-2019, 11:39 AM
#2
Re: Injectors are NOT firing
He "thinks"?!? Get a new mechanic. This should be easy to track down. Check for power to the injectors. Check for injector pulse from the ECM. If you get nothing there check that the ECM is getting a distributor reference pulse. If it is then check for power supply and ground to the ECM. If you have all that the ECM is bad.
GD
GD
icm or could be vats
08-20-2019, 12:48 PM
#5
Re: Injectors are NOT firing
A bad key reader would cause vats to act up.
to test I’m assuming this is a 1227730 ecm. There is a blue wire in cavity f10.
you can turn the key to the accessory position. If it’s working correctly you will have 2.5v on this blue wire.
https://tpiparts.net/1227730_pinout_diagram
if you have loss of spark as well it’s more than likely the icm or pickup coil. Could be a wiring issue heat can cause damage to the four wires that connect to the icm that run to the ecm.
to test I’m assuming this is a 1227730 ecm. There is a blue wire in cavity f10.
you can turn the key to the accessory position. If it’s working correctly you will have 2.5v on this blue wire.
https://tpiparts.net/1227730_pinout_diagram
if you have loss of spark as well it’s more than likely the icm or pickup coil. Could be a wiring issue heat can cause damage to the four wires that connect to the icm that run to the ecm.
08-20-2019, 02:23 PM
#7
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Car: 1989 Firebird
Engine: 5.7 LS1
Transmission: T56
Re: Injectors are NOT firing
What they said, its possible the mechanic blew the fuse to the injectors during the install?
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08-27-2019, 12:08 PM
#9
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Car: 1989 Firebird
Engine: 5.7 LS1
Transmission: T56
Re: Injectors are NOT firing
Did you verify no pulse with noid lights? Do you have spark? If they were firing before replacing I would suspect a connection was missed or one or more injector could be bad (even with quality parts it can happen). I would ohm each in injector.
The wiring is pretty simple I would ohm each wire back to the ECU connection as my first step of the injectors ohm out correctly. Then test the icm and also make sure the rotor is turning in the distributor if no spark.
The wiring is pretty simple I would ohm each wire back to the ECU connection as my first step of the injectors ohm out correctly. Then test the icm and also make sure the rotor is turning in the distributor if no spark.
08-28-2019, 10:18 AM
#11
Re: Injectors are NOT firing
Calling out an ECM is NOT a simple process. It requires a lot of testing and verification.
GD
08-28-2019, 10:34 AM
#12
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Car: 1989 Firebird
Engine: 5.7 LS1
Transmission: T56
Re: Injectors are NOT firing
yea... I hate to say it but I would be finding a new mechanic, the ECU was working before the new injectors so unless he hooked the battery up backwards or did something else that he thinks fried the ECU there is no real reason to suspect it.
08-28-2019, 12:21 PM
#14
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Car: 1989 Firebird
Engine: 5.7 LS1
Transmission: T56
Re: Injectors are NOT firing
Do verify VATS.
Someyear cars have an inline ECU fuse beside the battery, and a wiring block behind it. If the mechanic fully removed the battery this could be effected.
My gut says he missed a connection or one went bad after unplugging.
Have you verified fuel pressure?
Someyear cars have an inline ECU fuse beside the battery, and a wiring block behind it. If the mechanic fully removed the battery this could be effected.
My gut says he missed a connection or one went bad after unplugging.
Have you verified fuel pressure?
11-19-2019, 10:40 PM
#15
Re: Injectors are NOT firing
Car has been repaired.. thanks for all the help guys.. the ECM was the issue.. bought a reman acdelco from rockauto.com and the injectors now fire correctly... i seem to have lost a vacuum hose and im not sure where it went, wat hose it was or where it goes but i assume its the reason for the rough idle and SES light.
pics of what im talking about
I think you need a new mechanic. Chances are that swapping the ECM is not going to solve the issue. He needs to check reference pulse and power/ground to the ECM before he determines it's bad.
Calling out an ECM is NOT a simple process. It requires a lot of testing and verification.
GD
Calling out an ECM is NOT a simple process. It requires a lot of testing and verification.
GD
it was indeed the ECM..thanks to all that helped.
Last edited by goalieforlife; 11-20-2019 at 12:51 AM.
11-19-2019, 10:53 PM
#16
Re: Injectors are NOT firing
I think you need a new mechanic. Chances are that swapping the ECM is not going to solve the issue. He needs to check reference pulse and power/ground to the ECM before he determines it's bad.
Calling out an ECM is NOT a simple process. It requires a lot of testing and verification.
GD
Calling out an ECM is NOT a simple process. It requires a lot of testing and verification.
GD
it was indeed the ECM..thanks to all that helped.
Last edited by goalieforlife; 11-20-2019 at 12:51 AM.
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