Somthing is very messed up 242 count's of knock..yep that right..HELP!!

Hello I'm not new to DSM's but new to this forum. I just got done redoing the head and t-blet, because I bought the car at a junk yard for 600. anyway it runs fine, but has issues everyonce in a while thats not the concern right now though. has 116,000 on bottom end, 200 on head and 149 150 149 151 numbers when cold

First off stock engine, just has a EVO manifold, and a little done to head. It's a 1990 gsx. IT running fine, but it will have little hesitations every once a while. Used to fall on it's face at 4000 but stopped doing that. Boost's to 9-10psi on autometer guage not stock guage. VAc is right at 18-19 at idle. Runs great, but tonight I did a log and got 7968RPM which I shift at 6 or lower amybe 6 and a hlf and 228 counts of knock. did it once though and never again, is my knock sensor going??? I know most engine's can't take 45 counts of knock let alone 228 I know it didn't have that much or it wouldn't have driven home, it did pull advance timing to 6 degrees when it's usually 45. Fuel trims are a bit on the lean side. L=114.8% which means the ecu had to add 14% more fuel. M=115.6% which ecu had to add 15.6% more fuel. 114.8% which means it had to ad 14.8% to get to thaT 14.7 MAGIC number. I think it may be a fuel pump or injectors. I need help as 228 is scary and very wierd. I know if it really did that much knock the engine would be toast.

So I need help, I can post the whole log if I find out how to lol.

Ohh yeah and at 6000 or so the MAF reads 1509.5 Hz isn't that a bit much for stock boost.

The turbo it's self may also be on it's way to turbo heaven because it wines louder than normal and it looks like it's leaking around the oil feed and turbo seal (hey it's got 116,00 on it) I plan to replace the turbo, but want to find out whats wrong first.

I really think my knock sensor is shot,

I can't beleave it said 228 counts of knock at 7968 rpm's...is my tach really that far off??

I found out it did it twice, but the second time it reached 8000rpm and 242 count's of knock

Also for that second my air temp went to 363 and my timing adv went to 260, and my coolent went to 278 form 199,and so I know somthing is wrong...could the ecu be bad???


thanks to all that help out

Derek

[CVD]

Your sensor shouldnt put out more than 43 counts. The only time I get more than that is when I turn off the car. Right as the ECU clicks off sometimes the logger will show 200+ knock.

[Wizard]

A knock sensor is basically a microphone that is tuned to certain frequencies. A bad sensor bascially means there is no sensor, or to the ECU, missing. Usually it will throw a CEL and revert to a default timing map. A knock sensor can give 'phantom' knock or a lack of knock counts depending on it's tune. This is adjusted by torquing the sensor to 16-18ft lbs. Anything other than that and you can expect problems. However, you haven't touched the sensor...........

So..........you mentioned earlier about how the car didn't want to rev past 4k (hint), unusual RPM and knock readings, strange MAF freq. readings, etc. Now is it possible that all of these are bad? Highly doubtful....consider where all the sensors send their input to get processed. Remember, your logger shows processed data from the ECU. It's not raw...ie. directly from the sensor itself. So...using your head a bit, you see many whacky sensor readings, bucking at 4k (had this happen many times) and just generally strange stuff...................Do you think that maybe the ECU is dying? I'd think so. Pull her out and take a look. It's free, VERY common and fits all your symptoms.

And yes, i've been in this same situation on a few cars. Especially the cutting out at 4k, which usually preludes the infamous center console clicking.

Wiz

[Wizard]

Oh yeah....and your tach isn't off.....it's also controlled by the ECU remember? The tach and boost gauge gets it's input from the ECU.

And a whining turbo isn't necc. a sign that it is dying. Go here and do these checks. May save you a few hundred dollars or more.

http://turbotech.com.au/trouble.htm Be sure to also check the links on the side bar.

Wiz

[LightningGSX]

Your ECU and Knock sensor are fine, its either your logger, cable, or a comm error.The reason I think this is, you said your IAT showed 363, and since the ECU only sends 8 bit(0-255) variables to the logger, the max scaled IAT it could send to the logger is 358, even if its not working properly.So basically, broken or not, its not possible for the ECU to actually send that data.Try a different cable or reinstall the logger.And make sure the RS232 signal ground(the ground on the logger cable) is making a good connection to the ground on the vehicles data connector.

[LightningGSX]

The 7968 rpm sets off a flag too, that happens to be the max scaled RPM the ECU can send as well.Your factory rev limiter is at 7500, so if the ECU thought the RPM was at 7968(or anywhere above 7500) it would of cut fuel instantly

[LightningGSX]

As I think about this more, it pretty much has to be the logger software(maybe a configuration error) or whatever its running on, not the cable.

[niterydr]

damm I was going to say logger software/cable error.
good call Mr. M.

[Wizard]

But would a bad logger/cable cause hesitation and/or stumbling. Especially at only around 4k? That is why I leaned toward an ECU problem more than logger problem.

Wiz

[LightningGSX]

Originally Posted by Wizard

But would a bad logger/cable cause hesitation and/or stumbling. Especially at only around 4k? That is why I leaned toward an ECU problem more than logger problem.

Wiz

In his original post, he said he no longer has that problem

[Wizard]

But still hesitates......., etc. I can read.

Wiz

[LightningGSX]

Originally Posted by Wizard

But still hesitates......., etc. I can read.

Wiz

Great you can read, so why have you talked about the 4k issue in 2 posts after he stated its no longer a problem?

[unreal808]

Are you dragging the knock sensor on the road?
sorry I'm no help.