Tuning Questions on 240sx Swap
01-15-2010, 11:05 PM
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Tuning Questions on 240sx Swap I have a 1995 240sx which I swapped in a ls1/t56 combo out of a 2000 firebird into. I had everything running earlier in the year but I had a horrible ticking noise coming from the driverside so I had the engine machined and freshened up and installed some forged mahle pistons. When I had it running earlier I had made a breadboard VATS circuit to get it started. Now I have HPTuners and I am hoping I have disabled VATS properly. Here are my question do I have to reflash the VCM after I have selected the VATS off?
Here is my second issue which is possibly related to the first. When I am cranking the engine trying to get it to run everything is showing activity except the lt b1 and st b1 as well as the lt b2 and st b2. Now from what I am grasping these are the fuel trims would these be active during a long crank? I have check the wiring and connections and everything seems as they were when the car was running. So if VATS was still active would this happen?
Sorry about the length. Thanks
Here is my second issue which is possibly related to the first. When I am cranking the engine trying to get it to run everything is showing activity except the lt b1 and st b1 as well as the lt b2 and st b2. Now from what I am grasping these are the fuel trims would these be active during a long crank? I have check the wiring and connections and everything seems as they were when the car was running. So if VATS was still active would this happen?
Sorry about the length. Thanks
01-18-2010, 10:36 AM
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i'll try and help a fellow 240 swapper as best i can.
? #1: yes you need to send the new cal to the ECM in order for the VATS to be properly disabled without an external VATS simulator.
? #2: your long term fuel trims aren't going to show anything on your VCM scanner if all you are doing is cranking the engine over, even if you already have a tune on the ECM you are most likely to notice the short term trims to change the most anyway.
so does your engine crank and not fire? or are you just getting your tune loaded up and have these general questions??
someone feel free to correct me, i'm a noob to HP tuners as it is.
? #1: yes you need to send the new cal to the ECM in order for the VATS to be properly disabled without an external VATS simulator.
? #2: your long term fuel trims aren't going to show anything on your VCM scanner if all you are doing is cranking the engine over, even if you already have a tune on the ECM you are most likely to notice the short term trims to change the most anyway.
so does your engine crank and not fire? or are you just getting your tune loaded up and have these general questions??
someone feel free to correct me, i'm a noob to HP tuners as it is.
01-21-2010, 02:09 PM
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Your LTFT's and STFT's won't work when the car is in open loop (open loop means the computer doesn't correct any improper fueling via the oxygen sensors). Even when the car is started, it runs in open loop until the car reaches an operating temperature set in the tune, which is usually 130+ degree ECT.
When you make the VATS change in the tune, you must do a rewrite entire to get it in there.
When you make the VATS change in the tune, you must do a rewrite entire to get it in there.
01-24-2010, 07:10 PM
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Ok the latest update-
today i went into vcm editor made sure in systems that vats was set to none and the went to the flash tab and hit write vin/tunerlock/vats then hit begin and everything went through and to say completed. So at this point vats should be off.
I still dont get anything to fire. The motor was recently rebuilt would there be any kind of problem with the rings not sealing properly because it hasnt ran yet?
I went through most of the sensors and everything so far is pluged in with no bent pins and i definitely have fuel pressure.
What sensor would cause this car not to fire at all?
today i went into vcm editor made sure in systems that vats was set to none and the went to the flash tab and hit write vin/tunerlock/vats then hit begin and everything went through and to say completed. So at this point vats should be off.
I still dont get anything to fire. The motor was recently rebuilt would there be any kind of problem with the rings not sealing properly because it hasnt ran yet?
I went through most of the sensors and everything so far is pluged in with no bent pins and i definitely have fuel pressure.
What sensor would cause this car not to fire at all?
