Bruce Melton
August 9th, 2006, 01:57 AM
DTC P1514 Throttle Body Performance
Circuit Description
The PCM uses the TP, the BARO, the IAT and the engine RPM in order to
calculate an expected Mass Airflow rate. The PCM compares this value to the
Mass Airflow value and the speed density calculation in order to verify the
proper throttle operation.
Conditions for Running the DTC
* DTCs P0601, P0602, P0604, P0606, P1515, P1516, P1517, P1518 are not set.
* DTCs P1120, P1220 and P1221 are not set at the same time or DTCs P1120 and
P1220 are not set at the same time.
* The engine operates longer than 1 second.
* The engine speed is greater than 500 RPM.
Conditions for Setting the DTC
* The PCM detects that the difference between the actual airflow (MAF) and the Speed Density calculated airflow is greater than expected.
* All of the above conditions met for less than 1 second.
This goes on to suggest TB problem.
I have had this a few times since new stroker with same LS1 Shaner TB as previous modded 346. Stock MAF. It happens during full throttle first or second gear WOT which is a traction limited event. The car drops to "reduced power" which is very dramatic and dangerous. Can be cleared and normal operation resumed.
Is it possible that in this condition engine is increasing air intake too fast for the MAF ? (beyond expectation above) If so what to do?
Tune seems otherwise fine.
Thanks for your thoughts,
Bruce
Circuit Description
The PCM uses the TP, the BARO, the IAT and the engine RPM in order to
calculate an expected Mass Airflow rate. The PCM compares this value to the
Mass Airflow value and the speed density calculation in order to verify the
proper throttle operation.
Conditions for Running the DTC
* DTCs P0601, P0602, P0604, P0606, P1515, P1516, P1517, P1518 are not set.
* DTCs P1120, P1220 and P1221 are not set at the same time or DTCs P1120 and
P1220 are not set at the same time.
* The engine operates longer than 1 second.
* The engine speed is greater than 500 RPM.
Conditions for Setting the DTC
* The PCM detects that the difference between the actual airflow (MAF) and the Speed Density calculated airflow is greater than expected.
* All of the above conditions met for less than 1 second.
This goes on to suggest TB problem.
I have had this a few times since new stroker with same LS1 Shaner TB as previous modded 346. Stock MAF. It happens during full throttle first or second gear WOT which is a traction limited event. The car drops to "reduced power" which is very dramatic and dangerous. Can be cleared and normal operation resumed.
Is it possible that in this condition engine is increasing air intake too fast for the MAF ? (beyond expectation above) If so what to do?
Tune seems otherwise fine.
Thanks for your thoughts,
Bruce