Quote:
Originally Posted by dkveuro
Fuel Pressure Idle: 55psi. Drops 10 psi or so under WOT and steady 53psi to 55psi cruising at 70mph. (Pressure gauge taped to windshield.)
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Is this fuel pressure regulator referenced to manifold vacuum? If so, pressure should rise the higher the load / lower vacuum.
Quote:
Originally Posted by dkveuro
Run road test over 4600rpm to provoke miss-fire and when checked at the coils.....always cylinders #1 and #3 coil packs have been cut off by ECU. #2 is still firing when checked by pulling coil loom connector off and not cut by ECU although the code set includes P0302..
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The ECU isn't going to cut out spark, it will shut off an injector to prevent raw fuel from overheating the cat.
Quote:
Originally Posted by dkveuro
I have watched the O2 on both banks under all sorts of driving conditions and they are reporting no lean condition. So, I have no 'Rich Stop Reached' codes or condition which lean injectors would trigger.
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The short and long term fuel trims likely won't react fast enough from the time the ECU sees a missfire and when it shuts off the offending cylinder.
Quote:
Originally Posted by dkveuro
When ECU shuts off #1 and #3 on road test, the O2 nearly flat lines and will range maybe 250mV to 400mV while the Bank 2 is normal....and back at the shop, #1 and #3 are dead.
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Yes, since 1 and 3 are pumping air, O2 voltage will drop.
Quote:
Originally Posted by dkveuro
Don't see fuel pressure as a problem, although I am suspecting injector/s. power up to 4600 rpm is great and all scanner tests get a pass.
regards
dk.
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