[s-cars] Detonation, HELP... (on the road)

[Joe Pizzimenti]

Change both knock sensors.  Could be that they're just dead.

Also, check out the fuel system, could be that the rising rate FPR ain't
risin no mo.

Good luck,
Joey

On 9/22/06, djdawson2 at aol.com <djdawson2 at aol.com> wrote:
>
> S-heads,
> I was on the road Weds night returning to CO from Montana.  I filled up at
> a Shell station (was very close to empty).  Shortly after filling up, the
> car began to ping audibly.  I was nearly home, so I babied it, and thought
> little of it.  Bad fuel, I figured... I'll refill it soon.
>
> Today (Thurs) I traveled from CO to Abilene, TX.  No change in the
> detonation situation.  If anything, it is worse.  I've been through several
> tanks of fuel.  I added some octane booster, which helped for that one
> tank.  Overall, however, the behavior has remained constantly poor.  So at
> this point, I'm doubting "bad" fuel has anything to do with the situation.
>
> This detonation is BAD.  We're not talking about high boost stuff... I'm
> talking about a very audible knock when anything above 0 boost is
> applied.  Any small grade, any attempt to pass.  You can even hear the
> engine detonate if you simply rev the engine in neutral.
>
> I have checked the line from the IM to the ECU.  It is fine.  Same with
> the line from the IM to the FPR.  I don't believe this situation is fuel
> delivery related.  I have a wideband O2 sensor in place, and the AFR is
> normal in no load and loaded running conditions.
>
> I believe something is providing or allowing too much ignition advance.  I
> never get a check engine light, so I'm doubting that I have a knock sensor
> failure... but I do not have any BTDT with a failed knock sensor.  I have
> changed nothing with the setup of the car.  It has been running for 60k
> miles with the same chips, fuel pressure, etc.
>
> If anyone has ever experienced or heard of this sort of detonation, I'd
> love to hear about it soon.  ANY ideas appreciated.  Hell, you can even call
> me with ideas.  I have to drive from Abilene to San Antonio Fri, so I won't
> be checking email except in the am.
>
> I'd love to hear thoughts, as this amount of detonation has me worried
> about completing the trip without blowing the engine.
>
> Thanks,
> Dave
> 303.570.3818
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