How much knock delay do you guys run in your chips ?

[turbotaone]

I have just pinned down the problem that I've been
chasing for the last six months. It's false knock !
Evertime I would nail the throttle the car would fall
on it's face (hesitate,stumble,backfire,etc.) and my
scanmaster would show 39 degrees of retard. If I
exelerated at a normal pace the car ran ok, it only
acted up when I would try to floor it. The fuel pressure
was 65lbs.at WOT and the 02's were in the high 700's.
So I figured the knock had to be false. I talked to a GN
mechanic and he told me to temperarely unplug my knock
sensor and see how the car ran, So I did this and the car
ran great. I put a new knock sensor in and torqued it to
the factory specs. just to make sure that wasn't the problem.
The car did the same thing with the new sensor plugged in.
I checked to make sure my down pipe wasn't hitting anywhere
and it's not, I have the poly motor mounts so I no the engine
isn't jumping around. The GN mechanic told me that I probally
have an older chip without a knock delay in it. He told me to
try a new chip with a 4 second knock delay. The chip I have now
is a Reds 93 that is at least 10 years old. I would like to know if
you guys run chips with a knock delay and do you think this is
what I need to get rid of my false knock ? My car is a TTA if that
makes any difference.

Thanks James

 

[Steve Wood]

Rather than doing that, have you made an attempt to find out what is the source of the false detonation? The usual suspects, if you will.

 

[re-evaluating]

False knock

Steve the false knock he is getting is from the transmittion during a full throttle down shift.. James you would be a lot smarter to pull the car down into first manually anyway before going to WOT, but go with the 4 second delay like Frank told you... There is no reason you should hurt the motor in the first 4 seconds of the pass unless your tune is completely off.. I always used a 4 second delay until I went with Felpro in my car and worked great for me, I was running 11.0's at the time.. Hope that helps.. Good luck with it. Dave

 

[turbotaone]

Thanks for the reply Dave.
I don't think that I know you, but you obviously know
that it was Frank Parvin that I was talking to. Maybe
I met you up on kenmore blvd. the one saturday night
that I was up there. I plan on hanging out there more
often once I get this car straighten out. Frank is a good
guy and he really knows his buick's. I had a good time
riding quads with Frank and his boy last Sunday. Hey,
maybe you were the other guy with Frank Sunday that
had the 400EX, I didn't catch his name. Anyway, I'm
calling Red tomorrow and ording a new chip.

Hope to see ya around Dave.
James

 

[re-evaluating]

Hey James

We haven't met I was just at Franks when you called.. It was kind of funny to see this post just after hearing the conversation a few minutes earlier.. You will really like the way that chip works. I am sure we will run into each other at some point. If you see a guy in a Gold T that will be me. Later Dave

 

[Steve Wood]

Why don't you check the ds engine mount? That is a common source of false detonation on a shift, etc.

have someone put the car in drive, ease into the gas while you watch the engine...if the engine suddenly lurches as the torque begins to work against the tranny, then you know you have a bad mount.

You can bandaid the problem, but if it is something like a bad mount, you may pay a higher price later.

 

[machinegun]

James, I think you are talking about me that you met up on Kenmore. I will hopefully be up there this weekend with my new car. See you there soon. I would listen about the down shift and I would make sure there is nothing causing the false knock. I have not looked at your car you just never know. Of course Frank really knows how to tune a buick.

 

[turbotaone]

Thanks Steve, but I have the poly mounts on my car,
so I don't think that's the problem,but I'll check it
anyway. Hey Machinegun, how ya doing? Your name
is Jim, I remember meeting you up at Kenmore.
I hope to see you up there again.

James

 

[Steve Wood]

doubt it.

You don't have a tight engine tie down on top of it, do you?

Noisy valve train can do it, but, I have not seen that much...and normally, that is not on, or near, shift points...will do it in Park as well

Sounds like the downpipe, or exhaust, is hitting something, or a loose IC bracket, etc.

Does it do it at launch only, or on any downshift? Thinking about wheelspin.

 

[turbotaone]

Steve, the car does it at any speed, as soon as I nail
the throttle it spits and sputters and back fires. When
I bought the car it had the old stock motor mounts on
it and the down pipe was smashed against the frame
and header so I figured that was the problem. After
replacing the mounts with the poly mounts I figured I
had the problem fixed. I have a 1/4" of clearance all the
way around my down pipe now, but the new mounts
didn't help a thing. The engine was supposedly rebuilt
about 5'000 miles ago so it should be good and tight.
I do have a new engine anchore that I have never put
on the car, maybe I should try that just for the hell of it,
it can't hurt. I ordered a new chip from Red today which
will have a 4 second knock delay in it. Hopefully that will
fix the problem until I can pinpoint the false knock.

James

 

[Steve Wood]

What does it do when you unplug the detonation sensor and then step on it...?

 

[turbotaone]

When I unplug the knock sensor the car runs great.
I never realized how good these cars ran until I unplugged
the knock sensor. I floored it from a dead stop and the car
walked sideways for about 100 feet with the tires smoking
and the tranny starting to shift through the gears until I
finally had to let off. I then took it out on the highway and
kicked it down at various speeds and it pulled strong everytime.
The 02's were in the high 700's and the fuel pressure was
65lbs. at WOT. This is why I figure it has to be false knock.

James

 

[Steve Wood]

It is certainly strange...I have no idea what could hit hard enuf to cause that amount of retard! I hope you figure it out.

Tranny mount good? exhaust pipe not swinging and hitting something around the hanger off the tail shaft?

Hard to see how it could with two poly mounts...I have only used one and it does not move.

 

[turbotaone]

It has a brand new tranny mount and a ATR exhaust
system that seems to clear everything well. Anyway,
thanks for your help Steve, I'll let you know if I ever
figure it out.

James

 

[BJM]

Put it on a dyno and put a video camera underneath so you watch things move.

 

[turbotaone]

I never thought of that, thanks BJM.

 

[GN ERGY]

There is a Dyno in eastlake, called Dynotech. they are listed in the phone book.
Tarey D.

 

[turbotaone]

Thanks GN ERGY, I'll check them out.

James