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Limp mode?


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First post so be kind ūüėÉ. My Barra converted XW Falcon has the following faults which I'm seeing¬†some advice on. Engine is BF2 running FG Manual ECU, coils & harness.

When we first fired it with a basic start up tune and stock FG XR6T injectors, it idled mint. Tuned now with the ID1000s, it has a slightly lopey idle like it has aftermarket cams and is fluffy under no load when picking up the revs. Under load, nice and smooth.

I'm running a full manual C4 trans. GPS speedo. As such, no speed input. I'm not currently running the factory boost sensor, as I'm using a GFB G-Force 3 controller with external wastegate. 

Ok, now the fault/s. After start up you'll get a few clean pulls at WOT or other inputs. Sometimes on return to idle, it'll run on like 4 cylinders and won't respond to input. Turn engine off and restart and idle is restored, throttle fine again. The other fault is, after a few boost cycles at WOT or other, it develops what feels like a limiter cut. It's more aggressive than a boost surge. Doesn't matter if you feed into it or attempt to mash the throttle, it simply won't rev out. Pull over and restart the car and it'll rev out clean again for a few cycles then fault will present again.

Because I went external controller, we didn't install the factory boost sensor. My tuner turned stuff off in the tune accordingly. However, he feels it may cleans things up if we re-install the sensor and turn stuff back on. I'm not across what tables it sees but he's confident this will fix our problems. The FG harness still has the plug attached so I'll get the boss welded on the pipe ready to go.

I don't the ability to log it so obviously don't know what codes it might be throwing up. If anyone has any clues of what we should be looking for that would be much appreciated. Cheers.

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Read the DTCs with Forscan and fix all of them. Being a conversion some may be normal. 

Next log your long term fuel trims, they should be within 5% if not the injectors have not been scaled correctly. This is critical for normal idle and low load. 

Next log spark source, torque source and throttle source during the limiter action. It will tell you exactly why it is occurring. 

Finally check mechanical issues like spark break down, valve springs, collapsed intakes/cats etc. 

This is all standard troubleshooting your tuner should be across. Who is tuning it? Are they a pcmtec Workshop? 


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