Thanks for your suggestion. I bought the truck new and the original pcm was
reflashed about 4 years ago by the dealer for some other problem and has
been perfect untill recently. I will check for vacuum leaks.
----- Original Message -----
From: "Tony Cellana" <acellan1@tampabay.rr.com>
To: <dakota-truck@dakota-truck.net>
Sent: Sunday, December 08, 2002 10:56 PM
Subject: DML: Re: severe detonation problem
>
> 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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