A/T 4speed fails, car wont move until hot.

[fixkick]

the OD flashed 12s..?

as you know engine full power must be at hand, 95HP on tap.
if not, the transmission can't do much. but get confused. (trans measures speed and engine load to shift)

so full power in 1st and second.
then fails to shift in to 3rd, at what speed,? and on what ground , flat.?
the Trans measure speed and engine load. if the load is too high, (low vacuum weak engine) the trans will not go to 3rd, nor forth, unless you back the throttle, and load drops and it shifts.
so the load is too much.
that means weak engine, and low vacuum confusing the TCM


here is the chart that shows all shift points.

3rd can be as late as 60mph at 85% throttle (threshold)
or as low as 23mph.
as you can see a weak engine will in fact, make all shifting late. by design.

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with the TCM pulled, you will see , just like all 5sp sticks see, low engine power.

you didnt say engine misfires. so...
filter dirty from bad gas?
low fuel pressure.?
weak MAF (or just dirty.)
Bad fuel

is idle rpm hot at 800, and hods 800 hot , selecting DRIVE.????

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the 3 >4th shift, can happen at 80mph, (with too much TPS angle or engine load)

[zukitrek]

Wow never new. I can check those speeds tomorrow. Filter has not been changed in a while. MAF was cleaned back in february or january (you saw the pics) Fuel press is the one that has not been tested. My idle has never been 800.

[fixkick]

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.

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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)??????????????

[zukitrek]

Ok. Will keep testing tonight. What I did this morning.
-Stall test was about 2k rpm on both drive and reverse.
-Just for the heck of it I pinched ISC and car wanted to die
-Measured vacuum at plenum and it was 21HG.
I could just simply change the FPreg as under my ownership it has never been changed. so it must be the original.
Will do a compression test tonight and check timing again.

thanks again and again and again....

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Fix BTW a huge cloud of white smoke went out on all stall tests.

[fixkick]

what is rpm hot idle, that is all that matters , step 1.
what is the number, ?
best is to do simple easy tests and replace parts $$$ last.
if the FPR looks old it is .....

good the ISC pinched. shows there is no huge plenum air leaks, nice test.
are you telling me you don't have a dash tachometer????, (2WD) many dont , most done. lacking the 4wd option with free tacho cluster.
my 4door 2wd had one. but was newer. sold to my mail man.....
If the idle is out of control there are simple reasons why ! (isc not jammed) too lean or too rich (misfires) or idle switch bad.

as with all cars, engines with low power. (lots of reasons)
why does stall test passing with 2000 rpm. seems like engine is very strong for this high RPM stalled. (but that is at 0 mph)
looks like its loosing power only on hills? and only driven fast.

A/T shifting is complex.
a tech would have to drive the car on the flat aggressively and then a hill to judge power.
my gut feeling is the A/T is 100% ok.
and lacks power on hills.
only.
just loss like, not 95hp but only have 60hp on hills. see? its not tranny slip. for sure.
it's lack of power. under certain conditions, at tech drives the snarf out car to learn that, and i cant.

the tech looks for lack of power at all speeds gears and loads.
and for misfiring and or clean linear bogging (like dragging a huge weight)

the trans is programmed to not up shift if the load/TPS angles are too large.
a fact.
if you had a real 1996+ car, we can read all that, on live scan, see TPS angle and load.
see maf output, etc. in fact all sensor data live.
on this car we cant. (unless you buy the Rhino tool)

low fuel pressure
FPR bad.
(im assuming engine timed right /compression over 150)
injector screens clogged.
fuel filter clogged
bad gas
maf last, but must work 100% at WOT or the power will never be 95hP nor will the trans ever shift right with a weak maf.
really what is wrong here, lack of 95HP on DEMAND.
1 hp per cubic inch displacement here.

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when i hear idle speeds wrong (still not reported yet, by you where RPM IS HOT)
my head goes. why.?
and wonders, is it too lean. or too rich? why.???? i never ignore problems, they like to stack-up.
they also can be the cause of the next hard failure. that early warning.
why ignore this , clear symptom.

if and engine is lean, running, it can burn valves. or ping (flogging a lean engine can do that)
i never ignore those early warnings

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are you sure this is 4speed
with OD lamp? (cluster lamp)
and OD switch? shift lever top.
and P/N tranny console switch??????
the 3speed, loves to smoke with the 3speed vacuum diaphram cracks.... 4sp has no such part.

some folks think TCC lockup is 4th gear, its not.
4th is a real gear and is aka. OD.

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sorry for dumb questions, im blind here, and drivelines vary.

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you saw the TCM with eye balls ,i think, so it's a 4speed.
white smoke, with ISC pinched is the PCV valve sucking oil, as the plenum vacuum goes to moon. ( 25inches HG,just before a stall or near stall, 400rpm)
or the worst case test for intake valve seals, at that horrific vacuum , at that moment.

[zukitrek]

Yes sir those RPM's are hot. Not even close to 800. But I does not shakes like a wet dog or want to shut off neither nor surges.
I forgot to tell you that the first shift (1st-2nd) happened at around 13miles per hour and tach close to 2k-1900.
Second shift (2nd-3rd) around 25miles per hour and tach 2k rpm. That was light acceleration not hard. It did shift on flat road not pressing the hell out of the gas pedal. It happened like 4 times in this morning road test.

[fixkick]

i got confused, there is cold idle speeds , hot idle and stall speeds/
what is the hot idle speed, in RPM, hot in park.? with foot off gas pedal. (900 , 1500 2000 rpm with foot off gas?)
or 500 , 700, what?
"My idle has never been 800.
Not even close to 800. "
these to inputs to me , tell my zero.... see why?




1>2 shift 13mph. the chart again shows, this can happen, take off in drive, get speed near 15mph and lift foot of gas pedal, is goes to 2nd, just like the chart shows. we can calculate the rpm but that is just 1st gear x rear axle ratio. easy to do . but not needed..
what matters is right foot, speed, rpm and if car is on flat ground or not.
tell me what you expect first then what happened, that made you think something was wrong.

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the TCM question
yes there are some folks driving with no TCM at all
skipping 2nd.
how you like this , you'd have to try it.
but you can see going up tall hills and skipping 2nd would be hard on the 3 gear clutch pack as it slams down.
but on flat ground piece of cake. a cake walk.

as you can see unplugging the TCM solves many issues.
here ill list them.
my trans does not slip. an any of 3 gears. (2nd cant be tested)
the other non 2nd gears, all work. great, and with full load up hills.
the TCM is not there, so if symptom is no gone then you found a big clue there. no?
you can see engine power for what it really is in 3 gears, good bad or ugly, no TCM to fool you or bad inputs to same.....
that is its purpose. in the FSM.
how you can use it , is up to you.

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what is hot rpm
foot of gas.
in park
?
you never once said. or i missed it
keep in mind i cant drive your car, if i could id see like 100 things, in 5min driving. vast things, sounds , speeds, vibrations, power, misfire, bogging, surge, (?) , and lamps and gauges. and what the road is doing.
none of that , can i do..... me blind

[zukitrek]

You missed it:

Yes sir those RPM's are hot. Not even close to 800. But I does not shakes like a wet dog or want to shut off neither nor surges.

I would say 500 maybe 700? But yes off the gas and hot engine.

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Well my bad about RPM numbers. I posted not close to 800 and that is not a number is a reference. but yes 700ish. Forgot to tell you also that my test drive was under Normal Shift Mode not using the Power Shift mode.

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if the FPR looks old it is .....
Is indeed old
You mention that they don't last 20 years so my guess this one is 20yrs old


looks like its loosing power only on hills? and only driven fast.
You are just right. Are you sure you are not picking from TX? Relating to blind comment you made.

low fuel pressure
FPR bad.
(im assuming engine timed right /compression over 150)
injector screens clogged.
fuel filter clogged
bad gas
maf last, but must work 100% at WOT or the power will never be 95hP nor will the trans ever shift right with a weak maf.
really what is wrong here, lack of 95HP on DEMAND.
1 hp per cubic inch displacement here.

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when i hear idle speeds wrong (still not reported yet, by you where RPM IS HOT)
my head goes. why.?
and wonders, is it too lean. or too rich? why.???? i never ignore problems, they like to stack-up.
they also can be the cause of the next hard failure. that early warning.
why ignore this , clear symptom.

Yes I have prolonged this too much.

if and engine is lean, running, it can burn valves. or ping (flogging a lean engine can do that)
i never ignore those early warnings
Would spark condition validate this?

are you sure this is 4speed
with OD lamp? (cluster lamp)
and OD switch? shift lever top.
and P/N tranny console switch??????
the 3speed, loves to smoke with the 3speed vacuum diaphram cracks.... 4sp has no such part.
Yes, pretty sure we have talked about this befiore(well written). OD lamp, n/p switch in dashboard, and button on AT lever etc.

some folks think TCC lockup is 4th gear, its not.
4th is a real gear and is aka. OD.

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sorry for dumb questions, im blind here, and drivelines vary.
Is Ok. Sometimes thinking while writing I skip parts so I don't always write what Im thinking. My bad.

white smoke, with ISC pinched is the PCV valve sucking oil, as the plenum vacuum goes to moon. ( 25inches HG,just before a stall or near stall, 400rpm)
or the worst case test for intake valve seals, at that horrific vacuum , at that moment.
No the ISC was not pinched at that moment. It happened on stall test only.

[fixkick]

ALL IS Good.
by blind, i mean, i cant drive you see all things at once, lots to see for sure...

were roasting down here in tx.
im in attic, putting in HDTV antenna. now... hot hot hot.....

[zukitrek]

Oh well we just had a heat wave for this time of the year. 103F heat index and some of these broken records. Sometimes temps would be 82F as early as 530am. Now it has gone down a bit. Ok will test tonight and report back to you.

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So your guess would be FPReg or need more data? Or at least fuel related? I don't remember changing that fuel filter in a while?