Injector forced open with engine running
#1
#2
Several possibilities.
I'd first rent a NOID light set from a big box auto parts store (AutoZone, O'Reilly, and Advance Auto Parts around here all have tool rental plans) and see if the ECU is commanding it to be on, or if it's mechanically stuck.
After that, it's easier to figure up what's broken.
Aside: My 1988's ECU decided to NOT fire one of my two throttle body injectors, and it's a moderately common failure on some MN12 Fords (1994 Thunderbird and/or Cougar with 4.6L V6's IIRC) to have the drivers short. Both were easy to figure out with the NOID light, not so easy without *grins*
RwP
I'd first rent a NOID light set from a big box auto parts store (AutoZone, O'Reilly, and Advance Auto Parts around here all have tool rental plans) and see if the ECU is commanding it to be on, or if it's mechanically stuck.
After that, it's easier to figure up what's broken.
Aside: My 1988's ECU decided to NOT fire one of my two throttle body injectors, and it's a moderately common failure on some MN12 Fords (1994 Thunderbird and/or Cougar with 4.6L V6's IIRC) to have the drivers short. Both were easy to figure out with the NOID light, not so easy without *grins*
RwP
#3
Noid light test
Thanks for responding. I did a noid light test and on the #6 cyl the noid light stays on. I replaced the computer but it still has the problem. What's weird is if I disconnect the connector in the middle of the wire coming from the alt. to the ASD box, it runs fine. The check engine light goes off and truck runs smooth.....but engine won't keep my battery charged.
#5
#6
Take the wiring diagrams in the factory service manual, and start tracing what you have in relation to what it says you should have.
I'd also "run the wiring harness" (i.e., with eyes and fingers) to see if there's a pinch or other problem in the wiring harness especially with the #6 injector.
The PCM normally grounds the injector to fire in most designs, so I'd be looking for a short that shouldn't be there - but DO check the FSM to make sure that's how it works!
RwP
I'd also "run the wiring harness" (i.e., with eyes and fingers) to see if there's a pinch or other problem in the wiring harness especially with the #6 injector.
The PCM normally grounds the injector to fire in most designs, so I'd be looking for a short that shouldn't be there - but DO check the FSM to make sure that's how it works!
RwP