No Injector Pulse Part 2
08-20-2020, 11:57 AM
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Car: 1989 ASC GTA
No Injector Pulse Part 2
Howdy,
I had posted a week back about an issue I am having in a 1991 Formula with the 5.7 TPI. The car will fire right up if i spray fuel into the plenum however falls because there is no pulse from the injectors, here is a list of things I have both tested and replaced in recent weeks.
Tested.
1. Injectors. I have 12 Ohms resistance at every injector.
2. Injector harness. I have 12 Volts on both plugs with the key 3/4 over.
3. I used a Noid tester (on one injector plug) and have no flashing when cranking.
4. Inspected ground at passenger side rear head to firewall.
5. Injector fuses under the dash and fuse at battery area as well as confirmed that there is 12 volts at the fuse block for injectors.
Replaced.
1. Refurbished ECM.
2. Vats bypass chip from Tuned Port Induction Specialties.
3. Distributor.
I did notice that there is a cut ground wire that is fastened to the metal bracket on the lower part of the steering column. I tried to find where it may have ran to however I can not find another end and assume it was for a previously installed alarm system. There is also another cut ground wire fastened to the inner body panel behind the passenger side kick plate which again may have been for a secondary alarm system that was once in the vehicle. It had both an older Auto Page as well as a Viper alarm system.
Automotive electric and electric in general is outside my wheelhouse so I may be missing something very obvious but from what I have researched the injectors are supposed to ground when the key is turned full over for cranking and my suspicion is that a circuit is not completing somewhere to enable this ground. I have also read that a bad oil pressure sensor may be a culprit but that information seems to be questionable. For what it's worth, the car has good oil pressure when fired and will go above 4 P.S.I while cranking.
If anyone can confirm what those two above mentioned cut grounds may lead to or where my next place to troubleshoot would be I would greatly appreciate it.
I had posted a week back about an issue I am having in a 1991 Formula with the 5.7 TPI. The car will fire right up if i spray fuel into the plenum however falls because there is no pulse from the injectors, here is a list of things I have both tested and replaced in recent weeks.
Tested.
1. Injectors. I have 12 Ohms resistance at every injector.
2. Injector harness. I have 12 Volts on both plugs with the key 3/4 over.
3. I used a Noid tester (on one injector plug) and have no flashing when cranking.
4. Inspected ground at passenger side rear head to firewall.
5. Injector fuses under the dash and fuse at battery area as well as confirmed that there is 12 volts at the fuse block for injectors.
Replaced.
1. Refurbished ECM.
2. Vats bypass chip from Tuned Port Induction Specialties.
3. Distributor.
I did notice that there is a cut ground wire that is fastened to the metal bracket on the lower part of the steering column. I tried to find where it may have ran to however I can not find another end and assume it was for a previously installed alarm system. There is also another cut ground wire fastened to the inner body panel behind the passenger side kick plate which again may have been for a secondary alarm system that was once in the vehicle. It had both an older Auto Page as well as a Viper alarm system.
Automotive electric and electric in general is outside my wheelhouse so I may be missing something very obvious but from what I have researched the injectors are supposed to ground when the key is turned full over for cranking and my suspicion is that a circuit is not completing somewhere to enable this ground. I have also read that a bad oil pressure sensor may be a culprit but that information seems to be questionable. For what it's worth, the car has good oil pressure when fired and will go above 4 P.S.I while cranking.
If anyone can confirm what those two above mentioned cut grounds may lead to or where my next place to troubleshoot would be I would greatly appreciate it.
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