bad KR

I need ideas from the crowd on a bad KR issue. My 99 Riv has intense Stage 1X cam, injectors, custom tune, slp headers, high flow cat, 103 autolights, new Walbro pump, new fuel filter, genv blower, KN filter, new bosch o2, new wires, 160 stat.
The car sees up to 13 KR even at part throttle. It comes down to zero slowly, but is happening anytime I start to get on it. From a dead stop, flooring it, it spikes high and will come to zero as it goes through the gears. It doesn't matter if it is 30 or 90 degrees out. Intense scanned it a few weeks back and could not see any reason for it (fuel trims also looked good). We checked fuel pressure and thought maybe it was a little low and slow responding when reving motor. We thought is was possible the 130K fuel pump was slow to build pressure and causing it to run lean. I bought and installed Walbro pump and fuel filter, but found no improvement. I also thought the fuel pressure regulator could be an issue. I swapped it with a used one I had, with no improvement. One thing to mention is when I swapped this complete setup from my old Riv, I did not get around to doing the Case Learn. Could this be the issue?
I always run 93 octane fuel, plugs and wires are new. I have lots of spare parts, so to eliminate other possibilities I swapped out the throttle body a couple days ago. Complete with different IAC, throttle position sensor, and MAF sensor. No change. I have also swapped out MAP sensor.
One thing I forgot to mention, when the engine is below normal operating temp, The scan gauge shows 0 kr and runs great. After just a few minutes running, it is up to about 160 and problem is full on. As mentioned before, I still need to do a CASE learn. I am trying to get with my buddy at the GM dealer to borrow the TechII (I have to catch him after the service manager leaves for the night
Also, as mentioned before, the complete setup was swapped from my 98 Riv.
When I had it dyno tuned, it ran great but had the same issue but to a lesser extent. From a dead stop, wide open, close to zero kr, but jump on it while rolling, and get high kr. Funny thing is, if it had high kr, you could quickly let off gas, then floor it again and KR was gone! It is for this reason, that I always thought something was sticking (maybe vacuum related?). Could it be I did something wrong when I did the GenV swap??
Since the 98 Riv had same issue but different motor than I have now, I would think that would eliminate the possiblity of my wiring harness or knock sensors being bad (since they are different now).
I used the 99 ECM, but we copied the custom tune from the 98 computer. So one thing constant between the two cars is the tune.
I also sometimes wander if the EGR is sticking open or something silly like that. I have swapped it out to, and run it unplugged. No change.

To me, I would guess the engine is lean. Would a vaccum leak cause the issue? I searched and can not find leak. What would be the best way to find leak? Injectors sticking? Bad ECM? False knock? Anyone have ideas? 

Welcome, Kevin. I'm sure we'll get to the bottom of this. First: how much boost are you running, and what size SC pulley?

What is your LTFT when the KR starts? What is 02 at WOT?

If you are lean, fuel injectors may need cleaned. Mr. Injector will do all 6 for around $100. What kind of injectors are you running?

Did you do the "boost bypass" mod? This is often accompanied by "flash KR" that is similar to your description.

Does your IAT sensor report a reading?

Aside from all the above, I kind of suspect the tune here. When was it done, you say you had some KR. If your car is like mine, it has less KR on the dyno and more on the road because there will be more load. Also, it is normal to have more KR when you hit WOT from a roll in higher gears (but 13º is not normal!). Did you have your shift points tuned? This can help to keep you out of low RPM/high load KR territory.

When below normal operating temp, your KR sensors aren't active, so you're probably getting knock. If you listen you might be able to hear it. This is bad for the engine, but it might be the way you can tell your knock is real. The KR sensors can be tuned to activate at a lower temp, btw. Another reason I question the tune.

I have been tuning my car for 7+ years, probably 50-100 PCM flashes, and have never done a CASE learn. I've even swapped out the engine and didn't do one. If ever your PCM thinks it needs the CASE learn, it will let you know with a DTC.

I would definitely need to see a few scans as part of determining what's going on Kevin. Welcome to our forum!

If Intense was scanning it... well they pretty much know what they are looking for! But we can definitely investigate as best we can. I'd also suspect tuning. They tend to do a pretty aggressive timing table, but again they would have seen that in scanning.

The KR while cold thing - it is correct that the PCM won't apply KR until the engine is warmed up. Somewhere in the tune is a minimum temp to activate KR, it could be about 150. I can't recall exactly right now, but what you are seeing there is normal.

Is it possible the headers are contacting the sway bar under load causing a false KR hit? Mine was very very close. If the motor mounts were weaker I could see that making contact.

Hey, thanks for the responses. I have not got to mess with the car this week.
Thanks for the explanation of why I see no kr when engine temp is low.
As far as the headers hitting the sway bar, I think I am ok there.
I am running a 3.4 pulley. I show up to about 11lb boost at 6000 rpm.
I do not know what the "boost bypass" mod is.
You ask: What is your LTFT when the KR starts? What does LIFT stand for?
The car just recently started starting hard. I checked fuel pressure (42-62). I notice when I turn the key to run, the guage goes to 42 the imidiately goes down to close to 0. so when I first crank motor it fires then dies. As soon as I crank it again, it fires up and is fine. I never noticed this issue before I started messing with the fuel pressure regulator. Question: should the fuel pressure remain and not bleed off? If so, what part in the fuel system is suppose to hold pressure? The regulator?
You ask: Does your IAT sensor report a reading? I have no codes, is that what you mean?
I am also not sure what you mean by shift points tuned. I do know the shift points have been raised.
Thanks for your time.
Kevin

It sounds like you messed up the Fuel Pressure Regulator. When you first Key On, the fuel pressure should jump up to about 55psi or so and STAY. It should NOT bleed off. That's probably why the car starts then dies...the initial fuel pressure feeds back to the tank. Once you get it running, the Fuel Pump supplies enough pressure to keep it running, but not like it should.

What exactly did you do the FPR?
FYI you can check it with a Vacuum Gauge. Take off the vacuum line that goes to hit, and hook up a vacuum pump directly to the FPR. Apply about 10-15 in/Hg to it and see if it holds......

Do you have any other mods besides the 3.4 pulley?

To set the fuel pressure, hook up your gauge, and with the engine running and vacuum line off (and plugged so there's no leak) set the FP to 50. That could be a part of your KR problems.

My 99 Riv has intense Stage 1X cam, injectors, custom tune, slp headers, high flow cat, 103 autolights, new Walbro pump, new fuel filter, genv blower, KN filter, new bosch o2, new wires, 160 stat.
I guess the next thing I will try is a new fuel pressure regulator. It's only money, Right?? I will let you know what happens.
Thanks

Don't replace it unless you know there is a problem with it. Just start by setting it to the right pressure!

Ok, I replaced factory fuel pressure regulator (they are not adjustable). No change. Same bad KR, still not holding fuel pressure when key is first turned on. I called Intense, they think the check valve in my new Walbro fuel pump is bad. They are sending me a new one.

To top things off, the tranny is going out. I just happened to send my spare tranny out for a refresh about a month ago. I had told my tranny guy no hurry, but I guess I am ready for it. He said its apart and he will finish it next week. Now, do I keep driving it and hope it doesn't leave me stranded, or park it? What the heck, I have free towing with AAA!

I guess I can not play anymore till tranny is done.

Kevin, glad to see you're getting closer to figuring this out.

The boost bypass valve (BBV) is a vacuum operated valve that allows air to flow around the blower, into the intake manifold when the car isn't needing power. The boost bypass mod is a way to "program" the boost bypass valve to start using boost earlier than the OEM setting. This can result in "flash KR". Sounds like you haven't done this - just asking.

LTFT stands for long term fuel trim. If your AF mix is lean, your LTFT will read positive (+) as much as +16.4, indicating the PCM is trying to correct by adding fuel. Zero LTFT is ideal, but usually it okay to swing +/- 5 or so. In some cases mine goes +8. As long as you aren't maxing, the PCM can correct in theory. Even so, seeing LTFT near zero is reassuring that your PCM is happy with AF ratio.

IAT sensor is the sensor that reads intake air temperature. Mine failed once and caused me to run lean, making KR. Doesn't seem like this is your problem.

Good luck with the new transmission. If your trans isn't making mechanical sounds yet, maybe ok to drive. Mine was going out a few years ago, started slipping. I made it home 500 miles, then started hearing mechanical failure - it was sprag teeth breaking off according to the rebuilder. I had just enough left to drive to the shop, but just barely. If you aren't hearing anything bad, maybe take it easy and see how it goes?