Question about 2000 Jeep Grand Cherokee
Replaced compressor and accumilater ,vacummed and charged system. worked fine for a short period cooled with no voltage drop, then same problem
Hot or cold engine or both?????????
first off the engine must be good. is it?
does engine have full power. driving (shoe falls off other foot....)
does the idle speed regulate?, with added electrical loads.
800 rpm hot. i turn on blower, then HL, RPM, will drop a tad and correct to 800 this is called idle speed regulation, a feature and function of the PCM and ISC air valve.
is the ISC is dead, (no reg) then the a/c will overload the engine.
"pulls down all vehicle voltage" so is that the only ISSUE? just voltage??????
what is the RPM at the drop. 400? the alternator dont work at 400 sorry..... and if true, dont fixate on voltage. it's RPM at issue....
do find out if the ISC is working first.
then if its working and the compressor drops RPM then its bad.
easy huh>? (engine has full power in all cases. tuned up and full power from engine at all times)
if the ISC is dead, clean, it.
i hand to clean mine every 20k for 500k miles on 3 jeeps
shoe falls again?
does A./C work? above 799 RPM? (means idle and faster)
I wish i knew full symptoms... so can answer far better.
what works and not. engine ,driving, hot cold engine.
idle controls, etc.
pretend helper cant drive car.....
the ISC is a servo , it's a closed loop servo system. controlled by
software (firmware) in the PCM.
it keeps idle correct at all times, and for SURE with a/c on
many cars increase idle speed 200 RPM with AC on.
this software, (magic? ) opens the ISC valve (adds air)
and corrects IDLE speed drops for all engine loads.
1: A/C ON
2: all electrics, Head,lights, defrost and blower are big loads.
3: going from Neutral /park to drive , it still regulates RPM.
does your ISC work in all 3 modes.
hold rpm constant, at 800 hot.? (id didnt look up fsm spec for exact RPM , but you can)
the ISC works in bipolar way, it can add or subtract air
raising and lowering RPM, at any time.
Posted on Jul 20, 2015
Belt worn, loose or idler pulley weak --compressor clutch binding,moisture in system ,compressor internal damage
Posted on Jul 19, 2015
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Posted on Jan 02, 2017
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