Can't figure this out. L92 (LS3) on 0411 pcm.
05-18-2017, 08:37 AM
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Can't figure this out. L92 (LS3) on 0411 pcm. Desperate for some help here, any advice would be awesome. Sorry in advance if this becomes long!
Engine is a 2008 L92, and its running a 0411 PCM now, with the Lingenfelter box. 700r4 trans. Using a gen3 MAP/MAF and TB from a LQ4. LS3 intake, and 56lb injectors (#12598646). It has a comp cams Thumpr cam. Headers and free flowing exhaust.
I double checked continuity on most of the harness yesterday and found no bad wires to the coils, injectors, MAP, MAF, IAT, and ECT. The LED on the Lingenfelter box is solid green (should mean that the crnk/cam sensors are good). It has the gen4 knock sensors (on the sides of the block) wired to the PCM.
The car was idling fine a month ago. Tune was rich when driving (plugs were black), but we figured it was good enough to get it running and to the dyno.
2 days ago it started acting up when driving home. Car will barely start, idles poorly, and seems to be very rich. Idles if you keep your foot into it.
Changed the plugs with no luck. Changed the PCM too. MAP is working (4.5v KOEoff). IAT/ECT sensors are good.
I’m out of ideas. The tune is speed density, open loop - based from a LQ4.
Should I unplug O2’s even though its in open loop?
Could it be the knock sensors?
I don't get how it can go from idling/driving OK, to flat out junk.
Intermittent sensor?
Engine is a 2008 L92, and its running a 0411 PCM now, with the Lingenfelter box. 700r4 trans. Using a gen3 MAP/MAF and TB from a LQ4. LS3 intake, and 56lb injectors (#12598646). It has a comp cams Thumpr cam. Headers and free flowing exhaust.
I double checked continuity on most of the harness yesterday and found no bad wires to the coils, injectors, MAP, MAF, IAT, and ECT. The LED on the Lingenfelter box is solid green (should mean that the crnk/cam sensors are good). It has the gen4 knock sensors (on the sides of the block) wired to the PCM.
The car was idling fine a month ago. Tune was rich when driving (plugs were black), but we figured it was good enough to get it running and to the dyno.
2 days ago it started acting up when driving home. Car will barely start, idles poorly, and seems to be very rich. Idles if you keep your foot into it.
Changed the plugs with no luck. Changed the PCM too. MAP is working (4.5v KOEoff). IAT/ECT sensors are good.
I’m out of ideas. The tune is speed density, open loop - based from a LQ4.
Should I unplug O2’s even though its in open loop?
Could it be the knock sensors?
I don't get how it can go from idling/driving OK, to flat out junk.
Intermittent sensor?
05-21-2017, 06:25 AM
#4
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Surely if the box was giving trouble..the OEM ecu would be reporting some crank/cam errors itself ?
You say the tune is speed density open look from an LQ4...yet you mention you have a MAF sensor ?
Are all sensors reading sensibly when it does run ?
What sort of injector pulse widths are being sent to the injectors ? And are the injectors etc correct for the ecu/tune you are using ? ( and fuel pressure etc )
You say the tune is speed density open look from an LQ4...yet you mention you have a MAF sensor ?
Are all sensors reading sensibly when it does run ?
What sort of injector pulse widths are being sent to the injectors ? And are the injectors etc correct for the ecu/tune you are using ? ( and fuel pressure etc )
05-22-2017, 03:39 PM
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Thanks for the replies. So the car hasn't been to the dyno yet, this basemap was just so we could idle it and drive it lightly around and test everything out.
The car will idle when warmed up, with IAC counts at about 54.
The MAF is still disabled, but connected to the PCM, and when idling the MAF is at 79 g/sec or about 3000Hz.
O2s were still disabled in the tune, but they were physically connected up. Mv's were about 700-850.
I enabled the PCM to go into closed loop, we found the O2s were pinned backwards (one bank went real lean and the other went rich), but I don't believe this was the issue, since the tune was in OPEN loop.
When warmed up the Injector PW was 2.8 mS for both banks.
The car will idle when warmed up, with IAC counts at about 54.
The MAF is still disabled, but connected to the PCM, and when idling the MAF is at 79 g/sec or about 3000Hz.
O2s were still disabled in the tune, but they were physically connected up. Mv's were about 700-850.
I enabled the PCM to go into closed loop, we found the O2s were pinned backwards (one bank went real lean and the other went rich), but I don't believe this was the issue, since the tune was in OPEN loop.
When warmed up the Injector PW was 2.8 mS for both banks.
05-23-2017, 12:35 PM
#7
Thanks for the replies. So the car hasn't been to the dyno yet, this basemap was just so we could idle it and drive it lightly around and test everything out.
The car will idle when warmed up, with IAC counts at about 54.
The MAF is still disabled, but connected to the PCM, and when idling the MAF is at 79 g/sec or about 3000Hz.
O2s were still disabled in the tune, but they were physically connected up. Mv's were about 700-850.
I enabled the PCM to go into closed loop, we found the O2s were pinned backwards (one bank went real lean and the other went rich), but I don't believe this was the issue, since the tune was in OPEN loop.
When warmed up the Injector PW was 2.8 mS for both banks.
The car will idle when warmed up, with IAC counts at about 54.
The MAF is still disabled, but connected to the PCM, and when idling the MAF is at 79 g/sec or about 3000Hz.
O2s were still disabled in the tune, but they were physically connected up. Mv's were about 700-850.
I enabled the PCM to go into closed loop, we found the O2s were pinned backwards (one bank went real lean and the other went rich), but I don't believe this was the issue, since the tune was in OPEN loop.
When warmed up the Injector PW was 2.8 mS for both banks.
79 g/sec is WAY too much fuel at 3000 hz