Re: Re: Computer was Jacob's Ignition

From: Jeff Lee (jlee@atlanta.nsc.com)
Date: Thu Apr 30 1998 - 10:01:50 EDT


catlin wrote:
>
> Well just to update everyone. I sent everything back including
> the wires. I called Mopar performance and they recommended the
> Mopar performance wires #P4876432 and Mopar performance cap &
> rotor #P4876255 so that's what I ordered. He said it was compatible
> with the computer. Speaking of computers the guy at Mopar performance
> ((248) 853-7290 phone number if anyone wants it) said that after market
> ignitions were a good way to ruin your computer. He said to reset the
> computer disconnect the battery so that's what I did. May take up to 1
> week for the computer to re-learn according to Mopar performance if
> I didn't damage anything he said. Great after everything Iv been through
> that's just what I need a brain damaged computer to match my own
> brain damage for tinkering with the ignition.
>

IMHO, this sounds like a bunch of bs. Unless the aftermarket system is
supplying excessive voltage, current, or nasty transients to the
existing computer or sensors (highly unlikely), it shouldn't be damaged.
I have a hard time trusting anybody who is trying to sell you
competitive products.

The SBEC is just a microprocessor, some memory to store (learned data),
a bunch of analog and digital sensor inputs, and a Flash ROM which
contains the program. The microprocessor just executes the canned
program in an endless loop and reacts to sensor inputs by modifying the
ign timing and the fuel timing/metering.

My understanding is that the aftermarket ign systems (and computer
enhancements like JET stageX) simply alter the sensor inputs to the
stock computer to make it "perform" better. The computer is a "garbage
in, garbage out" device, ie. if you give it poor sensor data it will
correspondingly make the engine run poorly through improper ign timing
and fuel timing/metering. The best way to improve computer performance,
is change the program, which is what you get when you buy the MP SBEC -
most likely a bone stock computer with a different program. Too bad
there are no aftermarket programmers or ROMs available for Dodge
computers like there are for Chevy...

Unless something electrically or physically damaged the computer in some
way (they really design these things to be pretty rugged as the
underhood environment is pretty hostile to lil' old electronics parts),
once you restore the original sensor inputs the computer will resume its
previous control patterns. Not sure what year your Dak is, but the 97-98
computers are supposed to adapt very quickly - a few hours to a day. The
older models do take longer.

jeff
98 rc 4x2 v8 5spd 3.55sg flares fipk



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