03JGC 4.7 HO blows injector fuse when flooring it. Before this installed new alternator,starter and rear upper control arm,since ASD relay to no avail,please help.

  • Does it blow when 'flooring it' in neutral? – HandyHowie Jan 29 '20 at 13:50
  • @HandyHowie some cars limit “free revving” to 3000rpm when not in gear, so it may not become apparent... – Solar Mike Jan 29 '20 at 14:02
  • Yes it blow when flooring it in park. – Phillip Blaquiere Jan 29 '20 at 17:04
  • 1
    if you slowly increase revs to maximum in park does it happen, or is it just when you floor it quickly? When you floor it, is does it happen immediately or just when the revs max out? – HandyHowie Jan 29 '20 at 21:50

Bad injectors can cause this also, most have a resistance of about 14 ohms, but can drop much lower with age or contaminated fuel, which causes more current draw (amps). Go to the parts store and see if they have one for your model, then use an ohm meter to see what the resistance is for a new one, then compare that to all your injectors.

Replace any that are 2 or more ohms lower in resistance.


Seen similar issues before where the engine moves due to torque reaction and forces something metal into contact with the wiring somewhere which causes a short and the fuse blows.

Good luck finding it... It takes luck and determination with attention to detail.

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