Re: severe detonation problem

From: Tony Cellana (acellan1@tampabay.rr.com)
Date: Sun Dec 08 2002 - 17:56:59 EST


If you are not the original owner, it may have been replaced witha MP PCM
which requires Premium.

If this is the case, look at the PCM for a part#, and reply back with it.
Someone will be able to tell if its a stocker or MP.

Something else to consider is an intake leak. Cracked vacuum hose or
nipple, bad TB or intake gasket. You can check this by spraying some carb
cleaner or such around the intake with the engine at idle. If the idle
changes, you have an intake leak.

There are other possibilities, but these are 2 of the easiest to rule out.

TonyC

-----Original Message-----
From: Jim Miller WB5OXQ <wb5oxq@grandecom.net>
To: dakota-truck@dakota-truck.net <dakota-truck@dakota-truck.net>
Date: Sunday, December 08, 2002 3:56 PM
Subject: DML: severe detonation problem

>
>Just over the past 3 or 4 months my 99 R/T has developed a severe
detonation
>problem especially at full throttle but noticable even on the cruise
control
>pulling a slight incline. I have changed nothing that should cause the
>problem over the past 4 years. the truck has 49k miles on it. I checked
>inside the t'body to look into the manifold and it is very clean so I dont
>suspect the belly pan gasket. I have tried techron fuel injector cleaner
as
>recommended by a local garage owner that specializes in tune ups and I am
>running 89 octane fuel but that has not helped. I hesitate to take it to a
>dealer because I am afraid all they know to do is retard the timing enough
>to stop the knocking and I suspect that will take a big retard as bad as
the
>knock is. I know that will hurt mileage and performance a lot and since
>timing is ecm controlled it should not have gotten out of adjustment. I
>wonder if low fuel injector pressure could be the problem? I have no way
to
>check this. I do not believe there are any vacuum leaks either. I am open
>for suggestions because right now I have to drive very gently to avoid
>knocking. Any help would be greatly appreciated. I may have to make a
trip
>to Pflugerivlle.
>
>



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