Knock Retard when accelerating

[mikesarebetter]

also.. just so you know matt. i borrowed my buddies efi live and used the pcm you said since it doesn't have one specific for our cars. the scanner read 0 on about five runs.. and about 4-7 on a few other runs. than the next day i got it scanned with the hptuners for our cars.. and was runnin a consistent 5 kr every time we ran it.. about ten times.. so i would take what that efi live says with a grain of salt. not knockin efi live as it's a great program... but not specific for our cars!!

[JDCMoney]

does the fact your running a DHP v1 PCM with a stock pulley mean anything?!?

cuz according to 3800perf.....

"Developed with the average 3800 enthusiast in mind, this calibration has been designed and dynamometer tested and proven for the following vehicle modifications installed:
- 3.4” - 3.20” pulley
- Cold air induction system (brand not applicable)
- Cat-back exhaust system (brand not applicable)
- Premium fuel (91+ octane)
*NOTE: This calibration is NOT intended for stock 3800 powered vehicles. Additionally, premium fuel IS required."

[blueguy]

^^ DONT EVER...

Post that. Those things are YEARS old. Follow the Safely Modding Your 3800 Thread.

[xxmattfxx]

I've tried a few more things, and am still getting nowhere with this problem. Anytime I go into boost and am up around 100 in the MAP readings, I get way too much knock retard.

-dealership fuel injector drop test: no problems found (p0420 code somehow hasn't returned since this)
-compression test: all good at 180 lbs. in all cylinders
-MAF tuning: No Effect

Here is a current scan (no wot) that shows if I push the pedal down even just a little too hard, KR is there to remind me:
2210 from xxrzdxx -- Scan Depot dot net

Some of the scan is while waiting on drive-thru, but it is there in hopes someone can also identify the occasional sputter/vibration during idle. Scan was made with the Powertuner this time.

I really don't know what else there is to do, that I haven't done already...besides having to drive around like an old lady.

[Bio248]

to be honest i dont see much in the scan that would point towards why youre knocking so much. it seems as though the boost and KR are constant with eachother for some reason.

maybe its possible you have the exact opposite of a freak? maybe you need a butt load more mods?

[xxmattfxx]

I haven't always had these type of scans, it's only been for about a year or so now.

[FoSHO99]

Try gradually rolling through the throttle, or more slowly. Its harder to pinpoint anything when its just a couple blips or jumps of KR. I'll look at it more later...

[xxmattfxx]

As requested, here's a new one with a more gradual climb:
AccelGrad2410 from xxrzdxx -- Scan Depot dot net

Something that I have noticed in all my scans is that at the suggested PE enable point at around 100kpa on the MAP, I always hit this mark at only 20% throttle. While everyone else I've noticed seems to be more in the 30% percent range. With stock being around 40-45% throttle.

I do know that my LIM is leaking some oil where one of the larger gasket portions meets one of the small, rail type portion of the gasket. I don't think the dab of sealant at that point was applied right, when they were replaced. This is the meeting point near the 6th cylinder. I cannot detect any vacuum leaks, and is only leaking oil to my knowledge. Wanted to throw that in there in case there's a possibility it is related.

I do plan on running a fuel injector and then air intake cleaner through the top end this weekend, with the pressurized canister tool.

[FoSHO99]

Do you have the powrtuner or who is tuning it, what programs are you using for tuning? I don't see any 02's get past 900 on the narrowband in that scan but your also not entering PE that much. You must have PE afr at 11.5 or so? I would try adding 10% on the maf table from 6000 on up and smooth that out. Wait til the fuel trims settle back down and then post a scan again. See if a larger change in the fueling will alter the kr any. What is your PE enable tps at? Here is what mine is set at, but you can probably go a tad higher since your s/c.


Fuel -> PE -> PE Enable TPS
File Location: C:\Documents and Settings\Administrator\Desktop\BINS\2kturboE85roun d6.bin

Percent
RPM 0 40
400 40
800 40
1200 35
1600 35
2000 31.99219
2400 30
2800 25
3200 20
3600 20
4000 20
4400 20
4800 20
5200 20
5600 20
6000 20
6400 20

[xxmattfxx]

I have the Powertuner, but have put everything except for transmission settings back to stock. I've decided that my car is mostly stock and I could see maybe having to tune out 2-3 degrees of knock, but there is no reason for 7*+ on my setup without something being wrong mechanically.

[xxmattfxx]

Well, intake system cleaner had no effect whatsoever.

[FoSHO99]

Did you try adding 10% to the maf table at 6000 and up? I would also play with the AE table to see if it will do anything. Your narrowband readings could make it look like its just fine, but it is not very accurate.

[xxmattfxx]

I added 10% to everything above 6000 with PE enable mostly at 30%, and got the highest KR numbers I have ever had...12 degrees on the highway at about 85% throttle. Somehow these setting had the opposite of the desired effect.

[FoSHO99]

I added 10% to everything above 6000 with PE enable mostly at 30%, and got the highest KR numbers I have ever had...12 degrees on the highway at about 85% throttle. Somehow these setting had the opposite of the desired effect.

Did you let the fuel trims settle back down before scanning or WOT? If the ltft's are still learning the trims again, it will not lock in at 0 and will cause the fueling to be off until they are relearned. If you did all that and still got the kr, try the opposite, take away 10%.

[rah575554eg]

What I can tell you from experience that the misfiring and KR is probably coming from an intake leak. On my 03 GTP it was misfiring on the number four cylinder and sure enough it was an intake leak. That's something to look at. I hope that helps you! Good luck!

[xxmattfxx]

Wanted to report back on my recent findings.

On a hunch, mainly from the ticking when first started, I had been off and on checking for exaust smoke at the rear of the engine but could never spot anything. I read somewhere about holding a tissue around the suspected area, I at first I didn't notice anything, until I lowered it far enough to reach the bottom of the exhaust manifold and sure enough the end of the tissue started moving with the RPMs. This, I assume, would explain the 30*+ IAT readings over ambient with the stock airbox. New exhaust manifold and gaskets are on there way. I don't know for sure right now if the gasket is bad, or if there is a crack inthe manifold, but I only want to do this once. This hopefully is the root of all my problems, but if not, it is at least the root of some of them.

[FoSHO99]

Well if its a bad enough leak, it can throw your 02's off. Fix it, return the MAF table to stock settings, re-tune.

[rmcardle3]

Wanted to report back on my recent findings.

On a hunch, mainly from the ticking when first started, I had been off and on checking for exaust smoke at the rear of the engine but could never spot anything. I read somewhere about holding a tissue around the suspected area, I at first I didn't notice anything, until I lowered it far enough to reach the bottom of the exhaust manifold and sure enough the end of the tissue started moving with the RPMs. This, I assume, would explain the 30*+ IAT readings over ambient with the stock airbox. New exhaust manifold and gaskets are on there way. I don't know for sure right now if the gasket is bad, or if there is a crack inthe manifold, but I only want to do this once. This hopefully is the root of all my problems, but if not, it is at least the root of some of them.

Thank you for the tip about using tissue. I will try it. Did your exhaust issue resolve your other performance /KR condition?

[Seansta]

the vibration dampner spun , thus throwing vibrations thru sensors which is affecting pcm

[blueguy]

the vibration dampner spun , thus throwing vibrations thru sensors which is affecting pcm

Wut.