"Bernd D. Ratsch" wrote:
> That's true...under light throttle cruising, it pings pretty bad (IAC
> controls idle). Had that happen to me twice (blown gasket).
Me too. I'm betting that the pinging is due to the quality of the air that is
entering the combustion chamber. The magnum engines are designed to be right on
the edge of too much compression for pump gas and therefore are extremely
sensitive to intake air quality. When the gasket goes - the intake air is being
diluted by the oil vapors - that leads to pinging. Thats also why the pinging
gets worse when under load.
This theory is based on my having a leaking stock intake and very bad pinging.
Replaced MAP sensor (oil vapors kills them?) - pinging wasn't quite so bad.
Replaced stock manifold w/MPI and it got lots better but didn't go away
completely. This was very confusing as the MPI has a solid bottom. One day I
decided to pull the PCV off, plug the line going to the TB and put a vent on the
valve cover where it was - Bingo! Turns out that my leaving out the baffles on
my MP valve covers was pulling enough oil vapors through the PCV valve
connection to the TB to cause pinging still. Once the baffles were in, the
pinging went away completely. Then the MP computer went back on - a few tweaks
later and I'm pulling right up to 6k. Does anyone know how hard it was to keep
looking at that MP computer sitting in my garage for over a year (because I
couldn't use it due to the pinging)???
Latr,
Shane
ps - Don't leave the pcv off - you will be surprised how quick all kinds of crap
(sludge, rust, black flacky stuff, etc...) gets glued to the top of your motor
(on the inside!)....
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/MPComp/HookerSuperComps/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
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