Vehicle
2004 Dodge Ram 1500 4.7L 4wd 
Customer Concern
Surge when cold. No power over 2500rpm. Check engine light on at times.
Repair Procedure
Verified Customer Concern
Tech notes: Vehicle feels like it is hitting an engine revolution limiter
Check MIL Codes: P Camshaft/Crankshaft position sensor circuit intermittent
Test camshaft and crankshaft position sensor circuits: Passed
Test Camshaft and crankshaft position sensors by graphing on oscilloscope: Passed
Tech notes that stacking the pattern indicates that the camshaft position sensor to show 18deg retarted camshaft timing.
Inspect camshaft timing: Found failed timing chain and tensioner
Replace timing components and retest: Passed
Verify repair with a road test: Passed
Vehicle
1997 Chevy Express 1500 5.7L 
Customer Concern
Idle Surge When Cold/High Idle When Engine is Warm. No Check Engine Light On.
Repair Procedure
Verified Customer Concern
Tech notes: Vehicle feels like it has a vacuum leak for the idle concern. A look at data shows that all of the 5volt reference signal engine sensors are 1volt above normal readings
Check MIL Codes: No trouble codes found
Test 5volt reference sensors for proper signal voltage: Passed (All sensors are reading correct voltage with a volt meter)
Test powertrain control module for a short in engine wiring harness by disconnecting all circuits individualy
Tech notes that isolating the fuel pump circuit corrects datastream voltages
Remove fuel tank and found burnt wiring in fuel tank causing 12v fuel pump circuit to backfeed voltage on the 5v fuel level sensor circuit into the pcm
Replaced fuel pump and wiring
Verify repair with a road test: Passed
