No Pulse to injectors

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The PCM decides the pulse width of the injectors-you might want to check below that will caused a rich mixture

1. Excessive fuel pressure can be cause by restricted fuel return line or defective fuel pressure regulator.
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
NEEDINFONCAR
  • MEMBER
  • 2 POSTS
Sorry it is a 3.8 L. V6. Injectors are always open. We have replaced injectors, oxygen sensor, cat sensors, mass air flow sensor, and has new coolant temperature sensore
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
If its throttle body injection could be the fuel meter body-if not computer also for a MPFI
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CYEOMAN79
  • MEMBER
  • 5 POSTS
  • 1989 FORD MUSTANG
  • V8
  • 2WD
  • AUTOMATIC
  • 61,000 MILES
I am having the problem with getting too much fuel in the #1 Cylinder. I was told it was prob the fuel injector so I pulled it. Now im wondering if theres a way to test it to make sure its not something else and waisted my time and money on an injector. Thanks, Chris
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,005 POSTS
Dis help you any? https://www.2carpros.com/articles/how-to-test-a-fuel-injector We're here to help...If I cannot...Someone will!--The Medic
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
You should have left it in place for the testing. Now that it's out, you might as well replace it because it would be a lot of work to put it back together for testing. It's likely a bad injector. The only other thing to test would be for a short to ground in the trigger wire for that injector.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CYEOMAN79
  • MEMBER
  • 5 POSTS
Well I got the new injectors in and still having problems. I am getting constant ground to the ground wire in the injector when I know it is supposed to pulsate. I ran a jumper wire from the ecm to the injector and it sill isn't pulsing. The thing that has me puzzled is that its not a thing that happens all the time. It is a intermittent thing. Most of the time it gives me the problem but sometimes it runs good. Hope someone has an answer that can help me and I HOPE its not the ecm thats bad. Thanks
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
Either the trigger wire from the ECM to the injector is shorted to ground or the ECM itself is defective. Running a new wire doesn't help if the old one is still connected and shorted.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CYEOMAN79
  • MEMBER
  • 5 POSTS
I didn't leave the old wire hooked up. I cut it from the ecm and the injector and ran a new one thinking the old wire might be grounded out somewhere in the harness. What is the trigger wire? Thanks.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
That was it. If you're still getting solid ground signal from that wire as it leaves the computer, then you have a bad computer.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CYEOMAN79
  • MEMBER
  • 5 POSTS
Ok got ya. The bad thing is where I bought the car replaced the ecm about 9 months ago I was having the same problem then and they replaced it. The bad thing is the one they bought and put in only had a 6 mos warranty.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
You could have another problem that is overloading the quad driver in the computer and burning them out like a shorted injector.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)
Tiny
CYEOMAN79
  • MEMBER
  • 5 POSTS
Ok. Well I just replaced all the injectors. Now the thing that has me going crazy is that it dosent do this all the time. It is an intermittent thing. I always thought if a computer was bad its bad not intermittent.
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Monday, June 8th, 2020 AT 11:31 AM (Merged)

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