Acceleration + Idle problem:
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Joined: Jul 2011
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From: Gainesville, Florida
Acceleration + Idle problem:
HISTORY:
Drove to town, 4 stops, started, ran fine each time, then drove home, 25 miles at 60-70 MPH, plenty of power, excellent acceleration, no roughness whatsoever, got home and shut off the key. The next day I tried to start it, and it just surged, and shook, but wouldn’t run, so malfunction apparently occurred just before or at the time I turned off key; and I got Codes P0107 lean, P1506 IAC over-speed error, and P0453 EVAP ECS sensor High.
I was eventually able to get it to run/drive “roughly” by screwing in the Anti-Diesel Screw, bypassing the IAC Valve.
Subsequent repair attempts:
Cleaned the Throttle-Body & “butterfly” Did a “smoke-Test” for Vacuum leaks—None detected.
Replaced:
MASS Airflow Sensor (Complete body),--IAC Valve,--PCV Valve,-- Throttle Position Sensor (TPS), --EGR Valve,--Fuel Cap, Fuel Filter,--Fuel-Pump.
Fuel pressure at the Rail, Engine Running =65 psi.
Idle is still a bit rough, and Acceleration is terrible! Bogs down when increasing throttle, but ‘speeds-up” some when I back-off slightly, indicating that fuel delivery is not keeping up with throttle-opening.
Once up to speed, 70-75 MPH it runs OK if not accelerating
Currently only two Codes, (No Miss-fire Codes).
1504, & 1506. (NO other codes): 1504: IAC Valve output circuit specific load failure detected by Power-train Module (PCM) (PCM is not receiving the expected electrical signal form the IAC Valve).
1506: Idle Speed too high
The latter or both may be caused by my increasing the Anti-Diesel Screw, but that’s the only way I can get it to idle without shaking, surging and/or quitting.
Also, not sure if/why IAC problems would cause poor acceleration, occurring at higher rpm, above idle?
I'm stumped. Not sure if the Surge Valve could be the problem, but with no additional Code's????
Drove to town, 4 stops, started, ran fine each time, then drove home, 25 miles at 60-70 MPH, plenty of power, excellent acceleration, no roughness whatsoever, got home and shut off the key. The next day I tried to start it, and it just surged, and shook, but wouldn’t run, so malfunction apparently occurred just before or at the time I turned off key; and I got Codes P0107 lean, P1506 IAC over-speed error, and P0453 EVAP ECS sensor High.
I was eventually able to get it to run/drive “roughly” by screwing in the Anti-Diesel Screw, bypassing the IAC Valve.
Subsequent repair attempts:
Cleaned the Throttle-Body & “butterfly” Did a “smoke-Test” for Vacuum leaks—None detected.
Replaced:
MASS Airflow Sensor (Complete body),--IAC Valve,--PCV Valve,-- Throttle Position Sensor (TPS), --EGR Valve,--Fuel Cap, Fuel Filter,--Fuel-Pump.
Fuel pressure at the Rail, Engine Running =65 psi.
Idle is still a bit rough, and Acceleration is terrible! Bogs down when increasing throttle, but ‘speeds-up” some when I back-off slightly, indicating that fuel delivery is not keeping up with throttle-opening.
Once up to speed, 70-75 MPH it runs OK if not accelerating
Currently only two Codes, (No Miss-fire Codes).
1504, & 1506. (NO other codes): 1504: IAC Valve output circuit specific load failure detected by Power-train Module (PCM) (PCM is not receiving the expected electrical signal form the IAC Valve).
1506: Idle Speed too high
The latter or both may be caused by my increasing the Anti-Diesel Screw, but that’s the only way I can get it to idle without shaking, surging and/or quitting.
Also, not sure if/why IAC problems would cause poor acceleration, occurring at higher rpm, above idle?
I'm stumped. Not sure if the Surge Valve could be the problem, but with no additional Code's????
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