EGR system

[Kevin]

sounds like tip in knock to me, nothing we can do about it. But i'll defer to the experts ehre

[carter200]

Originally Posted by secondchance

At tip-in. Goes away if I push the throttle more aggressively.

Sounds to me you need to mash that pedal on the right more and let that big dog eat Just funnin with ya

[secondchance]

Originally Posted by Kevin

sounds like tip in knock to me, nothing we can do about it. But i'll defer to the experts ehre

Are you saying this is typical? If so, I don't recall this occurring w/ my 91.

[secondchance]

Originally Posted by carter200

Sounds to me you need to mash that pedal on the right more and let that big dog eat Just funnin with ya

I hear you. I just have that "gotta run perfect" OCD.

[Kevin]

tip in knock is normal and there is no way to get rid of it.

[Aurora40]

By tip-in, you mean the knock that occurs when the secondaries open, correct? There's apparently some small amount of time between when the butterfly opens and when the extra fuel injector starts firing that causes a temporary lean condition and triggers knock retard.

If that is what you mean, then it may depend on your definition of "moderate" throttle. I.e. is it enough to open the secondaries.

That also shouldn't continue to happen while maintaining the same amount of throttle.

At least, this is my understanding. Not based on my expertise or experience (of which I have little).

[secondchance]

O.K. Back to metal (in our case, plastic) to the metal (fiberglass) option.

Seriously, I am thinking BG K44. Anyone had any good or bad experience with this?

Another option is GM top end cleaner spray into the horn (I know, interference motor, do not let the motor die...).

[Aurora40]

Have you scanned the car? Is it pulling timing and registering knock events?

[secondchance]

I talked to Jim from Westminster yesturday. He has a scanner but the connector will not fit 94.

He said he will bring Tech 1 just in case to Frederick for Cumberland run. I hope he remembers.

Will you be there?

[QB93Z]

I have the Tech 1 (an OBD I scan tool), but I do not have an adapter to plug the Tech 1 into a 1994 or 1995 ZR-1.

Note: "OBD I" means Onboard Diagnostics, first generation.

It turns out that in 1994 GM shifted the Corvettes to the newer OBD II style connector (under the steering column) but kept the OBD I computer interface. SO, I need an adapter (part # 3000053)

I also have a ADL Cable and interface to use the TTS DataMaster software to record operating engine data. The cable I have works on my 1993 and my 1990, but I need a special ADL cable to scan the later year ZR-1's.

I have ordered the ADL cable, but I won't have it by Saturday's outing.

I am looking for the Tech 1 adapter. Does anyone know where I can get one?

Jim