Timing pulled at 2600 rpm 5lbs boost. 0 degrees timing under load

[jon1440]

timing pulled.hpl



Gradually working my way to 50% throttle & to 2500-2600 rpms, maybe 5 lbs boost, my spark goes from a commanded of 12 degrees right to 0. Not so convinced that its burst knock because theres no real quick sudden change in airflow. I'm running this on 93 octane.


6.0, turbo, mild cam.

Also is it crazy to think maybe my exhaust is messing with the knock sensors? My exhaust exits the fender and is somewhat noisy.


Low and High spark tables are the same.



I don't remember the gaps of the plugs but they was adjusted for boost when installed.


I'm going to try and log Knock Retard and also Burst Knock. During my log I posted it didn't record Knock Retard anywhere.


Heres the latest log.
2102019.hpl

[5FDP]

Do you have a knock sensor code?

Hopefully you didn't disable any of those codes. Because from that log it's pulling what looks to be the maximum allowed knock retard of 8 degrees. That normally happens when a knock sensor code is active, I see it all the time of trucks with high mileage and water gets into the sensor holes.

ECM tables 12781 and 12780 are the tables to look at. They should have the max value of 8 degrees of knock.

I wouldn't trust them to work right when you are in boost if it spikes to 8 degrees of knock like that.

Make sure non of your spark correction tables or torque mngt is causing the timing drop.

[jon1440]

Latest loaded tune

2102019.hpt

I haven't cleared any codes and the DTC's are set to MIL on second error. 12781 and 12780 are set for 8 degrees. And my spark correction tables are zeroed out. My maximum spark retard is set at stock settings which is fine. If the engine knocks then I want it to pull timing. I guess for a test I'll try decreasing the timing first and see if it goes away. If it doesn't then I guess decrease the tables you mentioned above. I'm trying to think of all test possibilities before doing anything drastic. My timing is right around 30 degrees which could be high but was stock settings in that area. But what I'm seeing on the log the tables 12781 and 12780 settings, are spot on for pulling timing. It will start pulling timing at 80 kpa. My hyst is 1.

I haven't messed with the torque reduction Retard tables. I assume your talking about the tables under Torque Management?


I'm trying to wrap my head around how I can setup the advance timing with knowing I could make positive pressure at 2000 rpms or it might be 2500 rpms before pressure goes positive. I don't want to have timing be lacking if it isn't necessary. Is there a sub-table for this in relation to the spark advance tables?

I'll first lower timing in the region where I'm seeing timing being pulled and see what happens. If anything, I could pull the charge pipe, lower the timing to something I know the engine wouldn't knock like 10 degrees and if the timing gets pulled then I know theres something wrong with the knock sensors, some setting that's to aggressive, or possibly my Knock sensors just like giving me hell.

Thanks

[5FDP]

My point with the knock retard pulling timing at 8 degree's in the 2nd log was that there could be an issue with the sensors. If you have a knock sensor code or pending code it may point towards that issue. I see it where people do not buy factory AC delco knock sensors and those codes keep appearing, so they just disable them to stop the computer from pulling max timing.

[5FDP]

While you are in there, max out the calc airmass P1514 table under engine diag so that isn't causing some weird issue.

Also this thing has to just be drinking fuel. It can dip in and out of PE so easy because you left the throttle enable at 20% and the PE enable at only 80kpa and you are driving around at those values almost all the time just getting up to speed.

[jon1440]

10-4. While I'm thinking about it, when there are multiple settings for PE, does every threshold, or setting have to crossed before PE is triggered? Or does only 1 threshold have to be crossed before PE is triggered?

I was having an issue with fueling at idle and cruise being to rich awhile back and changed the settings. I also have PE activated at 20% torque. Should I raise both Torque and TPS? I got the idea from another thread about using these settings, but if they didn't ever reach 80 kpa in their PE settings at part throttle then I could see why it worked for them.

I appreciate it

[5FDP]

TPS, RPM and MAP kpa should be the ones it normally using. I lower the enable torque if TM is disabled. It should enter PE/BE when at least 2 or even all 3 are crossed. For sure the pedal and rpm because on stock applications you could be at 100% throttle, over the 55kpa enable but not over the 5,000rpm delay yet.

I'd rather have it set similar to this when having PE and BE. Set PE map to 90kpa, BE to 105/110 (that way it starts when the table does), have the pedal at 40-60% because that's far enough down to where you'd be in it enough to make boost and not so low that you'd hit that value just cruising around.

[jon1440]

Do you have a knock sensor code?

Hopefully you didn't disable any of those codes. Because from that log it's pulling what looks to be the maximum allowed knock retard of 8 degrees. That normally happens when a knock sensor code is active, I see it all the time of trucks with high mileage and water gets into the sensor holes.

I checked the DTC's and have

102 Pending, Current
103 Current
327 Pending
332 Pending, Current, History


Is the Maf set up correctly to disable? I don't have a Maf on my setup.

[5FDP]

P0102 and P0103 are good, those need/want to be tripped for speed density.

The P0327 and P0332 are the knock sensor codes that when tripped with cause the knock sensor the calibration to hit the maximum allowed knock retard. Old and corroded sensors and or a bad harness are the most common issues.

Do some inspecting to see what's up. Replace the parts if required with ac delco parts. Those codes should stop coming up and on the off chance they don't even with new parts you can still test the sensors using a mallet on the engine block to make sure they read and just set the codes to no error reported.

[jon1440]

P0102 and P0103 are good, those need/want to be tripped for speed density.

The P0327 and P0332 are the knock sensor codes that when tripped with cause the knock sensor the calibration to hit the maximum allowed knock retard. Old and corroded sensors and or a bad harness are the most common issues.

Do some inspecting to see what's up. Replace the parts if required with ac delco parts. Those codes should stop coming up and on the off chance they don't even with new parts you can still test the sensors using a mallet on the engine block to make sure they read and just set the codes to no error reported.

Alright, I believe I'm on the right track. Just to clarify, these codes can be set with good working knock sensors or in the case of a bad faulty sensor?

[5FDP]

Yeah. I've replaced sensor before and the harness but still would get a P0327 code. So I disabled the codes and used to mallet or hammer to tap the block to make sure they would still read knock/vibration.

[jon1440]

Yeah. I've replaced sensor before and the harness but still would get a P0327 code. So I disabled the codes and used to mallet or hammer to tap the block to make sure they would still read knock/vibration.

Well, I was hoping changing the knock sensors would cure the disappearing timing issue but I'm still having issues. Changing the KS's did get rid of the DTC's though. Weird thing if you watch my log is if I go into the throttle with ease I can get past the timing drop, but if I go a little faster with my Throttle transition then it will momentarily goes to my commanded spark then just fall on its face. I believe when I updated my software from 3.26 to 4..... whatever, this started. Maybe its just coincidence, or I'm grabbing at straws. All I know its freaking annoying. I did see after the update, I gained some tables. Could something be added to cause this?


Before I could go right into Boost no problem. Timing did what I wanted.


In the log at 6:10:30 Timing stayed where I wanted, at 6:10:40 it fell on its face.2132019 1.hpl

[Lakegoat]

Looks like your throttle is going to zero. Do you have any splices in the wiring?

[jon1440]

Looks like your throttle is going to zero. Do you have any splices in the wiring?

No, its the stock harness. At what time did you see it go to zero?

[Nate Mell]

Jon1440 did you ever find a solution to this? I'm currently dealing with the same thing after swapping in a small stall converter..