blue94

iTrader: (7)

I got my scanmaster hooked up today and it is showing 10 degrees of knock retard when I do a full throttle run. That seems like alot to me....is this normal or do I have something wrong?

wrd1972

iTrader: (12)

That sounds high.
Do you have headers or roller rockers?

blue94

iTrader: (7)

neither...as far as I know anyways. Valve covers have never been off since I owned the car. Stock manifolds, it does have a gutted cat though. I went out again and normal part throttle driving around town and on the highway i'm getting as much as 2 degrees of timing retard. I'm also getting code 44 which my chilton manual says is a lean exhaust code. If my fuel pump is getting weak or fuel filter is clogged could that be causing a lean condition and the knock? The car also has a hypertech tune which could be contributing to the problem. I will probably tune it back to stock to see if anything changes.

blue94

iTrader: (7)

I drove around some more last night and seeing was as much as 2-3 degrees of knock retard in normal driving.

SilverZConvertible

iTrader: (1)

Yep your car sounds retarded. Do you have access to a tank of 110octane? If so see if you're still getting knock while running 110octane. If so I'd say its likely a false knock.

Do you have an LT4 knock module in your computer? The LT4 motors vibrated more than the LT1 and as a result the LT4 KM is less sensitive to False knock. Pretty standard upgrade when you go with RR and headers anyways.

dhdenney

iTrader: (53)

A Hypertech tune advanced the timing some. Were you using 93? I think they also recommend a 160 stat as well.

Rowdy94

iTrader: (13)

LT1s run on the border of knock anyways. You really need to get to a track that has 104 unleaded and log a run or two. That will tell you if it's real or false. Then you adjust accordingly. If it's real, retard some timing. If it's false, tune it out.

To tune out false knock i believe the low octane tables need adjustment. This may be wrong, and I'm getting ready to do the same process. Can somebody confirm that or debunk it and let us know the correct way to tune out false knock please?

blue94

iTrader: (7)

this was all on 93 octane, and I took the hypertech tune off today and put the stock tune back in, and am still getting a significant amount of knock. On a full throttle run tonight in the cool weather the highest knock retard recorded was 11 degrees. I have a 160 degree t-stat sitting around so I'll probably throw that in tomorrow, and than I'll see if I can scrounge up some 100+ octane gas.

Ls1Bait

To get rid of false knock you need to increase decay retard table and decrease attack table. Do these a percentage at a time false knock is gone.

blue94

iTrader: (7)

i'm looking at lt4 knock modules, and one of the sites I was looking at said it was 96-97 lt1's...is there a difference between the obd1 and obd2 pcms that makes the lt4 knock module only for obd2 cars, or is the website just wrong?

blue94

iTrader: (7)

put a full tank of 93 and 104 octane boost today, and it didn't change anything...so I'm guessing it is false knock...would an lt4 knock module help, or should I just get a tune?

Ls1Bait

It depends on what kind of other tuning is needed. If you need a tune or just want to put the car on the dyno then get a dyno tune. If you just want false knock gone then try a lt4 knock module. How much are they anyway?

Rowdy94

iTrader: (13)

Octane booster is not going to give you your answer. It won't raise octane anywhere close to near enough. You really need to try at least 104 unleaded. Try to go to a track for a night that has Sunoco.

I fell for the LT4 knock module garbage. If you do it and it works, you're one of the few. You really need to handle this the right way by using the race gas.

dhdenney

iTrader: (53)

Yeah I just diverted the whole mess by taking out my KS and setting all tables to 0.

Ls1Bait

^^^what...........?

Did you desensitize the knock sensor? Or delete it?

Rowdy94

iTrader: (13)

That works if he knows it's false knock. He doesn't.

C_Rules

iTrader: (7)

okay i have the same problem. let me tell you good luck trying to fix it. i tried the lt4 km and i logged the car after directly installing it. suprisingly no knock. i think its fixed so i log it the next day to be sure and surprise the knock is back everywhere. so i say to myself let me check to see that my valve lash is good. it needed some adjusting and so i did and guess what still have knock and now a MAP is high error code. i say let me go over the entire underside of the car to make sure i have no metal to metal contact. turns out my cat delete pipe is hitting the body of the car. so i get that fixed and log the car again unfortunately still knock. i want to find the knock so bad so that i dont have to desensitize my sensors but it's just not working. so i have to do two more things try the race fuel and have my car retuned for the new racetronix fuel pump. after that if i still have knock then im going to have to desensitize the sensors. oh yeah the car isn't going into closed loop nowadays so go figure.

p.s. sorry for the

dhdenney

iTrader: (53)

Took the sensor out of the block and put a plug there. I just set all the tables to 0 so there is no timing retard.

dhdenney

iTrader: (53)

Yeah but it's probably false. Stock motor with 93 shouldn't be knocking. If it weren't false knock, where would it come from?

infinitebird

iTrader: (11)

Older motors can certainly develop real knock from bad components or worn out parts, etc.