cam and heads now car wont stay running
10-28-2017, 03:45 PM
#1
cam and heads now car wont stay running
Just installed Texas speed stage 2.5 heads, torquer v2 cam 7.4 pushrods, 3200 stall converter with lg Motorsports long tube headers. Followed how to on ls1 tech, double checked everything as I went. 100% positive cam is dot to dot but did not degree cam. Everything electrical is hooked up. Sent PCM to ECS supercharging for base tune for mods so it would run and get a few heat cycles before being tuned locally. Car starts immediately and sound good and builds 40-50 psi oil pressure, run for a few seconds and dies, can't rev or keep running. Acts like it runs out if fuel. Checked fuel. Shows 58 psi when key is turned and hold while running and after it dies. Unplugged maf, no change. Is it normal with this cam and heads even after mail order tune to run so rough that I will have to have it towed to the tuner. Checked ground on back of head, it is connected. O2 sensors are correct. Left left right right and rears tuned out. Plugs were black but dry, replace with NGK TR6ix, no change. Any help would be appreciated, was expecting to start and idle at,east with mail order tune. Am I missing something? I have tried to search with no luck.
10-31-2017, 07:24 PM
#2
Le Mans Master
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St. Jude Donor '13-'14-'15
Really tough to diagnose without having the car here---
This might help---
When your engine is 1st started cold the engine runs in what they call "open loop" No 02 sensor data is being used at all and the fueling in commanded by your "open loop normal tablbe-----Once the coolant reaches approx 140* the ECM switches to "closed loop" In CL the fuel in now being adjusted via your front 02 data and corrected by your fuel trims
Once the engine is warmed past 140* and started it switches to a timer to switch to CL -- That timer is between 20 and 40 seconds---
How soon after it starts does it try to die ? and what is the coolant temp?
If started dead cold and it dies before the coolant hits 140* that would indicate another issue that is not OL/CL related--and most likely not enough "desired airflow" at start/idle
This might help---
When your engine is 1st started cold the engine runs in what they call "open loop" No 02 sensor data is being used at all and the fueling in commanded by your "open loop normal tablbe-----Once the coolant reaches approx 140* the ECM switches to "closed loop" In CL the fuel in now being adjusted via your front 02 data and corrected by your fuel trims
Once the engine is warmed past 140* and started it switches to a timer to switch to CL -- That timer is between 20 and 40 seconds---
How soon after it starts does it try to die ? and what is the coolant temp?
If started dead cold and it dies before the coolant hits 140* that would indicate another issue that is not OL/CL related--and most likely not enough "desired airflow" at start/idle
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Craighill2 (10-31-2017)
10-31-2017, 08:51 PM
#3
Really tough to diagnose without having the car here---
This might help---
When your engine is 1st started cold the engine runs in what they call "open loop" No 02 sensor data is being used at all and the fueling in commanded by your "open loop normal tablbe-----Once the coolant reaches approx 140* the ECM switches to "closed loop" In CL the fuel in now being adjusted via your front 02 data and corrected by your fuel trims
Once the engine is warmed past 140* and started it switches to a timer to switch to CL -- That timer is between 20 and 40 seconds---
How soon after it starts does it try to die ? and what is the coolant temp?
If started dead cold and it dies before the coolant hits 140* that would indicate another issue that is not OL/CL related--and most likely not enough "desired airflow" at start/idle
This might help---
When your engine is 1st started cold the engine runs in what they call "open loop" No 02 sensor data is being used at all and the fueling in commanded by your "open loop normal tablbe-----Once the coolant reaches approx 140* the ECM switches to "closed loop" In CL the fuel in now being adjusted via your front 02 data and corrected by your fuel trims
Once the engine is warmed past 140* and started it switches to a timer to switch to CL -- That timer is between 20 and 40 seconds---
How soon after it starts does it try to die ? and what is the coolant temp?
If started dead cold and it dies before the coolant hits 140* that would indicate another issue that is not OL/CL related--and most likely not enough "desired airflow" at start/idle
11-23-2017, 08:59 PM
#4
Le Mans Master
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St. Jude Donor '13-'14-'15
thank you for your reply. Had car towed to local tuner and all is well now. Contacted Doug at ECS and PCM was given wrong tune, it was given a tune for larger injectors and base tune for blower car, was very sorry for the mistake and offered to retune or refund. It was opening the injectors at the wrong time and would not run more than a few seconds. Thanks for you help, any insight is always appreciated.
You need to preform a "crank angle re-learn procedure"
Any tuner with EFILIVE or HP can do this OR some one with a TECH II or similar device---