0/-2 degrees timing on cammed 2006 GTO

[Brad Kimbler]

I just had a 2006 GTO dropped off with a BTR stage 4 cam...at first start this car barely pulled into the shop. After first log I noticed that total ignition timing was in the -2 to maybe 2 degree range with a very random case when it would actually fluctuate between 5/15. At this point I can't even drive car to start logging A/F ratio. Is there something I'm missing in the E40 computers with bigger cams? Or should I start looking into bad map,maf,crank,etc sensors? I attached log and file with all kinds of attempts to rid the 0 degree timing issue. Please help


WEIRD LS2 GTO LOW TIMING STUCK AT 0 DEGRESS.efiHopkins 2006 GTO engine tune_cammed_test.ctz

[joecar]

Tables B0141,2,3,4 (Open Loop Commanded Fuel) are overly rich at EQR 10.0... in OL this engine has a rich bog... problem with what just I said is that I see other stock E40 files with the same values (EQR 10.0).

I don't see why spark timing is being pulled down so much.

edit: I had left out a word.

[Brad Kimbler]

Tables B0141,2,3,4 (Open Loop Commanded Fuel) are overly at EQR 10.0... in OL this engine has a rich bog... problem with what just I said is that I see other stock E40 files with the same values (EQR 10.0).

I don't see why spark timing is being pulled down so much.

This issue reminds me of a LS1B computer where the knock sensors were putting it in some type of engine protection mode. Customer did stat that directly after the cam swap the car didn't have power to make it up hill. I don't know how they could have got the cam swap incorrect if my tach, and crank sensor is working. A crank relearn attemp may help? I haven't done that on an E40 setup yet. Is it worth a try?

[joecar]

This issue reminds me of a LS1B computer where the knock sensors were putting it in some type of engine protection mode. Customer did stat that directly after the cam swap the car didn't have power to make it up hill. I don't know how they could have got the cam swap incorrect if my tach, and crank sensor is working. A crank relearn attemp may help? I haven't done that on an E40 setup yet. Is it worth a try?

If tach is working then CMP/CKP should be correct (engine would run very badly otherwise).

You can try a crank relearn, if the ECM is erroneously detecting misfire then the crank relearn may help.

I don't see KR or KNKRET in the log file... so, yes, check the knock sensors, this might be what is going on.

[Brad Kimbler]

If tach is working then CMP/CKP should be correct (engine would run very badly otherwise).

You can try a crank relearn, if the ECM is erroneously detecting misfire then the crank relearn may help.

I don't see KR or KNKRET in the log file... so, yes, check the knock sensors, this might be what is going on.

Ok, well it won't let me do a crank relearn. From what I kn ow about the Gen3 stuff, if knock sensors are bad it won't allow a relearn. Maybe gen 4 is the same. I'll look into running a test on the knock sensors

[Brad Kimbler]

Only other thing to add is that they had the heads off during the cam swap to put lifters in. I wouldn't think this was a problem other than moving wires around that go to knock sensors, they look good but I better check them as well.

[joecar]

...
From what I kn ow about the Gen3 stuff, if knock sensors are bad it won't allow a relearn. Maybe gen 4 is the same. I'll look into running a test on the knock sensors

Gen IV behaves the same.