Here's one for the other Experts on the list...

From: Bernd D. Ratsch (bernd@dodgetrucks.org)
Date: Thu Jun 19 2008 - 21:00:46 EDT


2007 Dodge Ram 1500 - 4.7L FFV/545RFE - 19K miles

P0300 - Multiple Cylinder Misfire - Active Code when driving (Goes to stored
on next key cycle)

The code trips while driving from 1900-2500rpm under light load - Highway
Cruising

(1) Fuel Sample taken - good (no water and/or debris - ran through filter to
check)
(2) Spark Plugs all in excellent shape - Gaps still at .040 - .042"
(3) Coil's all firing properly with 8K to 20K volts (idle to 2500rpm 10%
load)
(4) Fuel Pressure: 59psi (Normal)
(5) Compression at 150-155psi in all cylinders
(6) Running Compression check: all within 2% of each other
(7) Vacuum at 18" at idle - Normal
(8) Software at current revision (checked against online database -
PCM/TCM/TIPM)
(9) Balancer straight - Checked with timing light and plate
(10) Serpentine Belt has no high/low spots (Yes, that can cause misfires)
(11) Battery Charging Rate - 14.3v
(12) Alternator at 70-80% Duty Cycle - Normal
(13) Fuel Volume - Fills 1qt in about 30 seconds
(14) LTFT Fuel Adaptives at +/-4 across all cells
(15) STFT Fuel Adaptives at +/-2 (Combined +/-6 - Within normal range)
(16) Misfire Monitor only detects the misfires at light load
(17) Cam and Crank sensors have a clean pattern on the scope - no spikes or
drops

So, any ideas?

- Bernd



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