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Cruise KR, and a lot of it.

DanPrixGTP

DanPrixGTP

Moderator
I posted this in my Members Ride thread, but I decided to create a different thread so I didn't add another 4,593 pages of non-sense to my Members Ride.

Lately, I've been having issues with cruise KR. Coming from a stop sign/red light and giving light throttle, the KR just escalates to 14.9* quickly and the car bogs down from pulling so much timing. It also does this as I'm just cruising on the highway as well. Only happens on light throttle, like 10 - 20%

No idea what's causing the issue, but it's getting pretty annoying.

Videos:

 


I had that exact thing and ended up changing both knock sensors. Just light throttle would cause it to lay over. I monitered KR and I'd was doing the same thing. Seemed once it got past a certain point it would drop off and the KR would at least drop to the 1-2 range then stop and stay at 0. Then other days it was fine for most of an hour drive. It started to get to the point that anytime I pulled into traffic I would wait instead of chance it. The bog from a takeoff mostly went away but happens every so often. I've driven it about 75 miles so far. I still have problems with it laying over anytime I try to go into boost but that might be a separate problem.
Jeff
 
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J57ltr said:
I had that exact thing and ended up changing both knock sensors. Just light throttle would cause it to lay over. I monitered KR and I'd was doing the same thing. Seemed once it got past a certain point it would drop off and the KR would at least drop to the 1-2 range then stop and stay at 0. Then other days it was fine for most of an hour drive. It started to get to the point that anytime I pulled into traffic I would wait instead of chance it. The bog from a takeoff mostly went away but happens every so often. I've driven it about 75 miles so far. I still have problems with it laying over anytime I try to go into boost but that might be a separate problem.
Jeff
Click to expand...


I've been told by one person that a Knock Sensor of mine could be broke.

Did changing your sensors help clear the problem?
 
It seems to have completely cleared the off idle take off KR and I haven't been logging it since I checked after installing them because if I get KR to read nothing else does, I lose ignition as a gauge, MAF everything. I did fine a totally easier method of r&bring the rear sensor, only took me forever the once I figured you can fish it out through the wheel well it mad it so much easier. I'm not scared to get stuck in an intersection anymore.

My other issue is I think my MAF is reading low.

Jeff
 
I had a similar problem once, was caused by the dr timing chain rubbing on the oil pump cover. Any throttle would max out the kr. Ran with the knock sensors disconnected for a while because of it.
 


I'm bumping this back to top, because I'm still having issues.

Cruise KR, (everytime I touch the pedal besides over 70%), usually pegs at 14.9* always. No idea why.

I unplugged my front sensor, and not much of a change. Unplugged my rear sensor and not much of a change again. Unplugged both sensors and the car still sees KR? No idea how that's possible. With both sensors unplugged, I typically always see 1.4* everytime I step on the pedal. Odd?

My cruise timing also sucks, with both sensors unplugged, I only see roughly 25*~ timing cruising on the highway, when I'm tuned for 40*

What's the deal here? Not trying to throw 2 knock sensors at it right off the bat, since they are quite expensive.
 
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Bad wire to the sensors? How the heck could the pcm pull timing with both sensors unplugged? Maybe check that rear sensor wire. I know my wire loom was all beat up and literally fell apart in my hands.
 
But even if the wire is bad, I shouldn't be seeing any KR at all with them both unplugged.

Maybe it is the PCM? and I don't get a service engine light with the sensors unplugged, but I haven't checked any pending codes.
 
Here is an update on mine, that follows what you have as well so bare with me.

My KR completely dropped off to levels that I have seen in other posts: KR when it kicks out of lockup a little on some acceleration haven't really been beating on it as I have other issues as well. My car has been literally been put back to stock condition (to the best of my knowledge, excepting a 180* stat).

When I was having knock sensor problems and went to change the sensors I unplugged the old ones and wrapped the new ones in several layers of Mylar bubble wrap (an old sunshade) I tie wrapped them out of the way and STILL had KR I asked on the board how this was possible, but didn't really get anything. It has to be in the software. I tested the wires back to the PCM and wiggled the harness and could find no open or shorted connection.

So I changed both sensors. The off idle KR and just about stalling went away completely.

One thing I did end up having an issue with was that my PCM that came with the car would allow/force the engine to go dead lean and acted all kinds of squirrelly. If I got on it and ran it through 1-2 and let off it would stay lean, then if I touched the gas it went dead rich the only time it switched was when I touched the pedal. Shut the car off and back on after opening the door. Start the car and The O2 would start switching again like nothing happened. I decided that I had PCM issues. Like someone messed it up something was wrong with it, but really suspected the tune. So I went out and bought an 04' GTP PCM from the junkyard. The car was totally stock and looked like a good candidate. I installed it and I'm not getting nearly as much as I did with the 05' PCM that seems to have a bad tune.

Did you ever change the O2's?

Jeff
 


Here's a video of the KR im getting Vs. Timing. Keep in mind BOTH Knock Sensors are unplugged. And yes, I am getting a pending code for "Low Circuit Voltage Bank 1 - Knock Sensor"

 
Here's a video of the KR vs. Throttle Percent. To show I'm barely even getting in the throttle and still seeing KR with no Knock Sensors:

 
And lastly a video of the timing advance vs. throttle percent. Has to be the reason I'm getting such sh*tty MPG. My cruise timing is stupid low for some reason. I figured with the sensors unplugged, my timing would go back to 40* as that's what I'm tuned for.

*Bad video quality, couldn't get my phone to focus while driving, but you get the picture

 
J57ltr said:
Here is an update on mine, that follows what you have as well so bare with me.

My KR completely dropped off to levels that I have seen in other posts: KR when it kicks out of lockup a little on some acceleration haven't really been beating on it as I have other issues as well. My car has been literally been put back to stock condition (to the best of my knowledge, excepting a 180* stat).

When I was having knock sensor problems and went to change the sensors I unplugged the old ones and wrapped the new ones in several layers of Mylar bubble wrap (an old sunshade) I tie wrapped them out of the way and STILL had KR I asked on the board how this was possible, but didn't really get anything. It has to be in the software. I tested the wires back to the PCM and wiggled the harness and could find no open or shorted connection.

So I changed both sensors. The off idle KR and just about stalling went away completely.

One thing I did end up having an issue with was that my PCM that came with the car would allow/force the engine to go dead lean and acted all kinds of squirrelly. If I got on it and ran it through 1-2 and let off it would stay lean, then if I touched the gas it went dead rich the only time it switched was when I touched the pedal. Shut the car off and back on after opening the door. Start the car and The O2 would start switching again like nothing happened. I decided that I had PCM issues. Like someone messed it up something was wrong with it, but really suspected the tune. So I went out and bought an 04' GTP PCM from the junkyard. The car was totally stock and looked like a good candidate. I installed it and I'm not getting nearly as much as I did with the 05' PCM that seems to have a bad tune.

Did you ever change the O2's?

Jeff
Click to expand...

Yes, I have replaced my o2 sensor with a Denso one. But I currently have my stock one in right now, because I was getting low MPG's and wanted to see if putting my Factory o2 back in would make a difference. Haven't switched them back yet, but my o2 MV seem to switching from high to low very frequently, showing it's working correctly. Might put my newer Denso sensor back in and see if any change.
 
That doesn't make any sense! You are showing a couple degrees of KR but you timing is WAY retarded. Has to be the pcm right?
 


bandook said:
That doesn't make any sense! You are showing a couple degrees of KR but you timing is WAY retarded. Has to be the pcm right?
Click to expand...

That's what I'm saying. I am completely stumped.

even with 1* of KR, my timing shouldn't be as low as 10-15 degrees when just cruising. It's causing my MPG to plum it. I'm averaging 14mpg right now, and it's really hurting my bank account lol.

I honestly have no idea why I'm even seeing any KR with both sensors currently unplugged. Where is the car seeing KR when nothing is telling it?
 
I actually meant knock sensors... My bad


the gauge reads -* as in degrees before, is this correct? I've never used one of those. But if that is the way it reads then that is low timing for sure. Mine would go to 0 and 15*adtc. It's done 10* atdc but I have some other issue as well. Mine was doing just that before I changed the knock sensors but it even did it with that other computer so I think in my case it was both the PCM and knock sensor. Did it just all of a sudden happen or progressively over time? Did it happen right after a tune?

Jeff
 
I think there is something in the program's get (either stock or aftermarket) that causes it to do so without the knock sensors connected. Like a default table of sorts.

Edit: remember that I am guessing on this as I have no GM program experience.

Jeff
 
I'll take a look at the tables in Tiny Tuner, but who knows if there is a hidden table that is causing this. There are definitely several tables that modify spark, but for your scanner to show KR I would think that could only come from one place-knock sensor. Its like having the MAF unplugged but still reading MAF frequency changes. Doesn't make sense to me.
 
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