What might cause high timing? [Archive] - GrandAmGT.com Forum

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realestdriver
12-29-2013, 08:40 PM
I have a recently LX9 swapped 2002 Alero. Under mild acceleration I get timing as high as 45* and of course this is followed by engine knock (very high as well). I was logging using hptuners at the time, but don't have a log available right now. My crank trigger/wiring looks good and no engine codes. I can't get my head wrapped around this problem, so maybe one of you have a better understanding of conditions that command timing.

sleepyalero
12-29-2013, 09:04 PM
Well I'm still new on tuning. But a few tweaks to your fuel and all that should help knock it down. Let other people chime in though. I have been having a guy tune my car it had high timing and kr but it's a lot better now after some tweaks...


And an alero huh? Interested in some LED tails for it?

Starglow
12-29-2013, 09:04 PM
What fuel injectors are you running? Do you have a custom PCM tune? Have you tried replacing the knock sensor and where did you mount it on the LX9 engine?

I asked that because you must use the 3400 knock sensor have it mounted in the exact same location on the LX9 as it was on the original 3400 engine.

Also the gap spacing between the crank trigger sensor and wheel is very important for correct timing. If the gap is too wide then that can cause inaccurate timing issues. Make sure the sensor mounting bracket bolts did not come loose from engine vibration.

sleepyalero
12-29-2013, 09:26 PM
This guy....

He's on it.

realestdriver
12-29-2013, 09:55 PM
22lb injectors on the motor. Stock tune until I get this thing settled down. The knock sensor is in the same spot as usual. I tried to match the crank trigger gap with that of my other LX9 swap but no difference. Did the case learn procedure too. I might just buy a few new sensors if adjusting that crank trigger doesn't help.

Thanks

sleepyalero
12-29-2013, 10:16 PM
So no on the tails then?

realestdriver
12-29-2013, 10:50 PM
So no on the tails then?

naw im trying to unload this thing as soon as I get it fixed.

sleepyalero
12-29-2013, 10:55 PM
Understandable.

Starglow
12-29-2013, 11:06 PM
22lb injectors on the motor. Stock tune until I get this thing settled down. The knock sensor is in the same spot as usual. I tried to match the crank trigger gap with that of my other LX9 swap but no difference. Did the case learn procedure too. I might just buy a few new sensors if adjusting that crank trigger doesn't help.

Thanks

You might want to try a different MAF since the PCM uses MAF sensor readings to adjust the air/fuel ratio....or at least clean the MAF that's on there now.

realestdriver
01-08-2014, 02:49 PM
I swapped out the MAF with the one from my DD, also the ignition module and coil packs. My laptop went dead that day but even with my handheld I still got a high of 52 degrees..WTF! Unplugging the knock sensor had no affect. I guess I'll buy a new crank position sensor and swap the PCM this weekend.

stewartfn18
01-08-2014, 04:37 PM
I should chime in since I think I know everything...

...but really I'm not into helping others. I just act like it.

realestdriver
02-18-2014, 09:17 PM
It was the EGR valve. After a few failed weekend attempts, I looked in hptuners at my spark table modifiers and the egr table was the only one with valves high enough to make should a huge difference. Unplugged the damn thing and normal spark was restored. Replaced with new EGR and all is well. Big relief, could have screwed up this engine in the worst way if I didn't know about the problem threw data logging.

stewartfn18
02-19-2014, 10:42 AM
mac had the same problem on his 99. though it onbly happened after he switched to the 00 plus style. at least you found the problem