Suddenly showing Knock...

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Oct 19, 2004 | 03:55 PM

houseofboost

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From: Kirksville, Missouri

Suddenly showing Knock...

My 383ci LT1 with YS-Trim blower is suddenly showing knock on the knock sensor deal. When I purchased the car, a few weeks ago, we drove the car in the heat and under boost it showed absolutely no knock. I got the car home the next day, approx. 20 degrees cooler, and the car shows knock with the same octane gas (114).

Have I bumped the sensitivity up on the knock sensor accidentally or is something wrong?

Thanks,
WB

Oct 20, 2004 | 09:43 AM

Got Me SOM

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From: Orlando, Florida

no you might be leaner now that its cooler. try adding a little more fuel.

Oct 20, 2004 | 03:44 PM

tici

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From: Zurich - Switzerland

Mhh... I have the same problem right now.
Is it possile, colder = lean?
Isn't the PCM using the IAT to compensate the fuel?
Or are SC engines too wild for a standard PCM?

Oct 20, 2004 | 05:22 PM

houseofboost

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My car has the Fel-Pro/FAST system on it.

How does a guy have the car tuned if you live in Missouri...where its 50 degrees today and tomorrow it will probably be 70 degrees?

Oct 20, 2004 | 05:40 PM

Phate

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I was under the impression that a FAST system would automatically adjust the A/F between a small range if it had a WB sensor. Might want to look into that.

In the mean time...in order to be safe you need to tune it for the leanest conditions that it will see. Detonation will kill a motor a lot faster then too much fuel, as long as the rings are broken in.

Oct 20, 2004 | 05:57 PM

houseofboost

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Thanks. I'm going to have it adjusted asap.

Gonna get it on the dyno in the next few weeks hopefully.

Oct 22, 2004 | 04:40 PM

jhelms

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Quote:

Originally Posted by houseofboost

Thanks. I'm going to have it adjusted asap.

Gonna get it on the dyno in the next few weeks hopefully.

Wes, good luck getting it on the dyno. Have you had any local races yet?

Oh yeah, if you have a chance to send those straps back we need to take one of Jimmy's cars to the track next weekend.

thanks,