the transmission is computer controlled, the 3speed is hydraulic magic, the 3speed has mech.govenor and vacuum modulator,that measure speed and load.
this 03L72E trans, is 100% electronically shifted, and has many sensors. it even shifts different when cold, using the ECT readings.
it uses tachmeters, (VSS2 speedp) and throttle angle (tps) and engine load , the ecu computes engine load at all time to the TCM.
the TCM takes those inputs and shifts like the table shown above. all modern cars now , are just like this.
some modern cars now have 3 speed sensors in the box, so it can shift even better... under all conditions.0
in fact this magic allows on box to run an many cars. (saves every one a fortune that magic)
the engine is weak the transmission KNOWS its weak.
and fails to shift, its programmed to do just that.
why the engine is weak has vast causes.
is it misfiring?????
is compression over 150psi on all cylinders?? wot? throttle open checked, sparks out.
yes?
if yes, we test the maf or the fuel pressure next.
you do know that most 1994 cars, the FPR is bad, now, most are dead, dying or weak. (FPR is on front of fuel rail)
the can cause horrid symtoms, they can stick inside, and pressure are no good at WOT.
the FPR on this car has a big job, it raises fuel pressure about 6psi as you get near WOT. if that dont happen the engine BOGS, and the transmission cant shift like you want.
is spark timing still at spec? if not the cam belt slipped.
is valve lash at spec, if not it burns valves.
even bad fuel can cause the filter to packup....
the fuel filter test port you see pressure go from 30psi normal and goes up to 50 ? filter is PACKED solid.
the test port is on pump side of filter, that is why it does that rise.
the idle not at 800 is a clear sign of trouble. but why not say what it is, ?
the ECU is programmed, to hold the Idle at 750 to 850 rpm hot. (not p/s overloaded, not A/c ON)
the ECU adjusts air flow to the ISC to do that magic, its an ECU servo. (regulator, servo action)
the ECU opens the ISC, to raise RPM
the ECU closes the ISC to lower rpm (hot)
if the AFR is lean it can fail (AIR/ FUEL RATIO)
if the plenum has air leaks , it will fail. (EXCESSIVE)
if the IAC is stuck open (bad) the ISC will fail to regulate. (THROTTLE CABLES TOO TIGHT,?) SOMEONE FIDDLED THE BLEED SCREW WIDE OPEN?
any vacuum leaks wild do that , fail. (excess)
i'd fix this (bad idle) first. because it's a parked car, hot idle. I don't have to drive and do dangerous stunts to fix this.... im parked.
is the ecu flashing 12;s (CEL lamp) on demand? paper clip test working?
Fixing idle bad causes, in many cases fixes the harder symptoms (power loss)
see why,
what if engine was too lean. and you found that, (low rpm) and that fixed full power up a hill.
what if?
what is your hot RPM at idle.????????????????
does the idle hold near 800 , when you turn on HL an dash blower fan at same time? (regulation tests)??????????????
this 03L72E trans, is 100% electronically shifted, and has many sensors. it even shifts different when cold, using the ECT readings.
it uses tachmeters, (VSS2 speedp) and throttle angle (tps) and engine load , the ecu computes engine load at all time to the TCM.
the TCM takes those inputs and shifts like the table shown above. all modern cars now , are just like this.
some modern cars now have 3 speed sensors in the box, so it can shift even better... under all conditions.0
in fact this magic allows on box to run an many cars. (saves every one a fortune that magic)
the engine is weak the transmission KNOWS its weak.
and fails to shift, its programmed to do just that.
why the engine is weak has vast causes.
is it misfiring?????
is compression over 150psi on all cylinders?? wot? throttle open checked, sparks out.
yes?
if yes, we test the maf or the fuel pressure next.
you do know that most 1994 cars, the FPR is bad, now, most are dead, dying or weak. (FPR is on front of fuel rail)
the can cause horrid symtoms, they can stick inside, and pressure are no good at WOT.
the FPR on this car has a big job, it raises fuel pressure about 6psi as you get near WOT. if that dont happen the engine BOGS, and the transmission cant shift like you want.
is spark timing still at spec? if not the cam belt slipped.
is valve lash at spec, if not it burns valves.
even bad fuel can cause the filter to packup....
the fuel filter test port you see pressure go from 30psi normal and goes up to 50 ? filter is PACKED solid.
the test port is on pump side of filter, that is why it does that rise.
the idle not at 800 is a clear sign of trouble. but why not say what it is, ?
the ECU is programmed, to hold the Idle at 750 to 850 rpm hot. (not p/s overloaded, not A/c ON)
the ECU adjusts air flow to the ISC to do that magic, its an ECU servo. (regulator, servo action)
the ECU opens the ISC, to raise RPM
the ECU closes the ISC to lower rpm (hot)
if the AFR is lean it can fail (AIR/ FUEL RATIO)
if the plenum has air leaks , it will fail. (EXCESSIVE)
if the IAC is stuck open (bad) the ISC will fail to regulate. (THROTTLE CABLES TOO TIGHT,?) SOMEONE FIDDLED THE BLEED SCREW WIDE OPEN?
any vacuum leaks wild do that , fail. (excess)
i'd fix this (bad idle) first. because it's a parked car, hot idle. I don't have to drive and do dangerous stunts to fix this.... im parked.
is the ecu flashing 12;s (CEL lamp) on demand? paper clip test working?
Fixing idle bad causes, in many cases fixes the harder symptoms (power loss)
see why,
what if engine was too lean. and you found that, (low rpm) and that fixed full power up a hill.
what if?
what is your hot RPM at idle.????????????????
does the idle hold near 800 , when you turn on HL an dash blower fan at same time? (regulation tests)??????????????
http://www.fixkick.com