Car has no power. 15 deg knock. Looking to maybe have it programmed.

My car seems to have no power lately. I am having constant knock that goes up to 15 degrees. I don't really know how to read the datamaster scan to tell what could possibly be causing it. Anywhere between 1800 and 2800 rpm, the car has no power at all. I really have to push the pedal to get it to go. If i decide to have a mail order programming tune done by madwolf or someone, will they look at a datamaster log before programming? Can anyone here check it out? Thanks for the help.

By the way, I have the LT4KM and always use 93 octane.

I noticed that my O2 voltage readings are nearly never 30mv apart, but usually a couple hundred. One example is 53/786. Any chance that this is causing a problem?

Datamaster file
http://rapidshare.de/files/32678746/home.uni.html


Here is the log hosted at another site. You still have to wait 40 seconds or something, but you don't have to go through multiple pages. I'll see if i can find another site that doesn't have a time limit.
http://www.megaupload.com/?d=KFQGFGNZ

The first thing I would do is ditch the LT4 Knock module. Mine gave me crazy knock counts.

Steve

Is there any way to donwload the file without waiting forever for the "ticket", then gettting a thousand ad's for upload services? I could never get to the point where I could actually download the file.

Your O2 values will never be the same, nor will they likely be within 30mV of each other in closed loop. Each bank of the engine is controlled independant of the other. At WOT (PE mode) you should see them very close, and relatively steady, but not in closed loop.

Do you have any DTC codes? DTC 43 (knock sensor) will cause the PCM to set its own knock retard values, based on other sensor inputs. You will have almost constant knock retard, ranging from a fraction of a degree to 15 degrees.

This is the best link I could find. Has a 15 second wait, then displays the link to the file

http://www.verzend.be/v/3090885/home.uni.html

I have no codes being thrown. I thought I had my mods in my sig, but I have Jethot LT's, Borla exhuast, no cat, and an electric cutout. My exhaust also rattles the shielding that is below the gas tank. Just telling you this because these may be possible causes of the knock.

The data log shows DTC 15, low coolant temp. But that must be a stored code, because I can't find it in the log.

Sorry, I cleared it after that log. It's no longer there. I replaced the sensor and forgot to clear it.

What mods? If none, then the tune isn't your problem.

Jethot LT's, Borla exhaust, no cat, electric cutout.

Jethot LT's, Borla exhaust, no cat, electric cutout.

Then the tune isn't your problem. Maybe a tune can get you a few HP, but you need to find and fix the problem first.

Probably the most knock retard I've ever seen in a data log. I don't think I've ever seen one max out at 15-deg before, after looking at hundreds of data logs.

Have you ever tried using high octane unleaded racing fuel to see if the knock is reduced? Have you tried getting your fuel from a different source?

I don't see anything in the data log that stands out. It is pulling fuel out in most cells, any where from 4% in Cell 15 to 11/14% in Cell 5. And the right bank is always pulling out even more fuel than the left bank, consistantly in all Cells.

TPS, IAC, MAP, MAF, etc. all look normal. The knock count just jumps up constantly.

If higher octane fuel doesn't solve the problem, you need to look for mechanical noise. I saw one case where a piece of RTV had gotten lodged in the end of the knock sensor and was transmitting huge amounts of noise to the knock sensor. Also could be a problem with something like the motor mount that is right next to the knock sensor being damaged or loose. But the knock retard appears in direct correspondence to the throttle opening up.

Thanks for taking the time to look over that log. I know it's a big one. Right now I'm just waiting for my gas to run low to go fill it up with some racing fuel. Would 110 octane be better than 100? They are both $8/gallon so it doesn't matter which one I use, just wondering if one would be better than the other for diagnosing this problem.

If the knock is still the same, I will look into replacing the knock sensor in the block. I've got to get this problem taken care of. Anytime you press the gas slightly, it feels like the car is falling on its face. There's a big delay from the time I push the pedal to the time it takes for the car to get moving.

110 octane [(R+M)/2)] is leaded. Use 100 unleaded.

any updates???
i'm have the same problem

Had to go out of town and needed to fill the tank up with 93. I will hopefully get to put the 100 octane in the car this week. I'll definately post back and let you know how it goes.

Just to update, I replaced the knock sensor and still get knock constantly. It seems to have toned the knock down some, but I still see 15 degrees.

yah here too i got 15* knock retard max sometimes less depends on rpm but I dunno what is casuing my problem either. Go easy on the throttle nothing happens. Mash the pedal or give it a quick snap and it just wants to die boggs stumbles whatever you call it, and the advance drops to zero and the retard goes to 15* . Now when it does this I dont here the motor making marble sounds or knocking. happens even in open loop too, just a few degress less retard but still reaches 9*

headers, no cat just straight pipe, magnaflow muffler, no egr.


So any help would be great too

Curious bubba, when you push the gas (not all the way, but a normal acceleration), does it feel like you're car is in a high gear like 4th when it should be in 2nd? I mean, the car is in the right gear, it just feels like it's not.

you know I have never thought of that or ever looked at that. It seems to be slower if I take off from the line rather than going from 30 and stomping on it seems alot faster. But that could have nothing to do with things i dunno

Is the exhaust hitting the frame or anything? Is it possible your knock module could be malfunctioning?

My knock is fixed. Thanks to everyone who replied. Turns out it was the LT4 KM as SABLT194 suggested. Swapped it back to stock, and I have 0 knock.

Can the knock modules get fried? I had it properly pulling timing(knock), then when I uploaded a new tune it stopped in the upload with a communication error. I put another upload on it and the car runs great. I now get 15 degrees timing retard all the time(I know it's not real knock). I'm not sure if the wiring to the sensor has a bad connection and it was just a coincident that I had the upload fail the first time, or if the knock module did get fried.

There are codes for a faulty knock sensor (or faulty knock sensor wiring) and for a faulty or missing knock module. Do you have any codes?

checked again since I couldn't remember what code I had and it was code 43 :(

Would you lean to wiring/sensor/module being the problem? The wiring isn't on the cross over pipe at all, but we did extend it when I did my wire tuck mod, but that was before when I had my nitrous setup and it ran fine back then.

If you have DTC 43, you will have continuous knock retartd, ranging up to the 15* limit programmed into the stock PCM.

The system is very easy to check:

-Key on, take the harness connector off the knock sensor. Measure the voltage, with the positive on the harness connector pin and the negative on the engine block. Should read 5.0V.

-Harness wire still off, measure the resistance between the single pin on the knock sensor, and the block. Should measure between 3,500-5,500 ohms, with 4,400 ohms being the "correct" value. (These are OBD-I values for the knock sensor, not valid for OBD-II)

-Key on, connect the harness to the knock sensor, and measure the voltage from the single pin on the knock sensor to the block. Should be in the range of 1.5 - 3.5V, with 2.5V the "correct" value. The PCM sets DTC 43 if the voltage on the circuit goes outside those values.

Wow, never knew or hear of that, THANKS though Fred, I'll check it!