Seized gearbox/torque convertor or something else?

[Nic_A31]

Auto gearbox in the Ceffy died on me yesterday, well I'm sure its the box, but looking for some input. Novel below.

When I bought the car, seller said it had some problems shifting, like staying in second when taking off, which was noticeable but driveable.
I noticed that 9 times out of 10, the HOLD/POWER switch only worked for HOLD, but wouldnt activate POWER, when it DID activate power, the gearbox would use 1st and 4th gears, and shift more appropriately, when only the HOLD worked it would take off from second (regardless of manual selecting 1st) and use either 2nd or 3rd even at 120+ kmp/h.
A hand written set of instruction for auto gearbox diagnostics procedure in the centre console tells me the problem wasnt exactly new.

The other night I noticed it started to hesitate under mid-full throttle, so I babied it, later Saturday night it began to use or not use 1st+4th while on the move. Came into a corner expecting to stay in second (in Drive), with the throttle up, it downshifted to 1st by itself, which to me sounds odd for ANY auto transmission (for the record I was decreasing throttle, definately did not increase throttle, not that I was expecting it to use 1st at that speed anyway)

Yesterday, same deal with the hesistation under load, babied it but eventually caught up to me, no gear would successfully go forward and it'd just hesistate and cut out. I let it cool down, got another 500 metres, again, died, again, cooled down, another 500 meteres and it was done, it also had a hard time revving up in neatral and park before I shut it off the final time, the revs sounded like something was resisting it, didn't sound engine related

Checked engine oil, looks nearly new, having only done 400km since service, started it up again in park and it revved fine, no resistance.
Gearbox oil....its almost clear a water, slight tink of pink and smells burnt.

Any idea's whats happened here?
Starting it in park and neautral is fine, even in gears for limited amounts of time is ok, I was able to drive it onto and off the tow truck, and idles ok in park and neautral forever, but as soon as it goes into gear, seems like it overheats and gives up.
Given the eletrical problems/confused nature of gear selection/shifting, and the state of the fluid I'm assuming this is a temperature problem between the flywheel and torque convertor?
I don't beleive it is the AFM as the hesitation occured at different spots on the rev range, not only at higher RPMs, was intermittent, and never the same (sometimes liked low revs but not high revs, then liked high revs and didnt like lower revs)

ECU is throwing 5-5, no drama's, even after a reset and run for a few mins.
Reset transmission computer but same deal. Havent done a diagnostics yet though.

Idea's?

[Z2TT]

I'd consider the following.

1. If you're car has a line pressure cable for the transmission, it may not be adjusted correctly.

2. You are using incorrect fluid.

3. Problem with solenoids causing it to take off in 2nd at the lights, most of the times the ECU/ECT will warn you of a defective solenoid via light on dash, am not familiar with how Nissans do this. Get a wiring diagram and some pinouts, and check the pins for each solenoid for resistance.

Other than that it could just be a mechanical problem with the box itself.

[Nic_A31]

Its become intermittent for now so testing possible causes is taking some time.
Gearbox is having problems of its own and fluid is absolutely rooted, so that needs attention.
Engine cutting out is suspected crank angle sensor.

NEXT QUESTION
(RB30E/RB20E head).... how are the crank angle sensor and throttle position sensors linked?
When I was trying to start it on Saturday, it'd turn over without starting as as I pumped the throttle, the RPMS would raise and lower (accordingly) in perfect sinc with my foot.....WTF ??
Could be looking at a fauly throttle position sensor instead of crank angle ?

Any feedback appreciated :)

[joshg123]

Wow so many strange things going on here, but may be linked

Firstly, the trans issue sounded like a kickdown cable having too much line pressure holding gears on, especially if it was hesitant to shift up and holding gears longer than it should, not knowing the trans fitted to the vehicle and if it has a kickdown cable or not, your 2nd post makes things interesting, if the trans ECU uses throttle position to determine your shift points and you have this strange engine RPM thing going on.

From memory RB's had a TPS with 2 plugs, with both used on a auto and only 1 being used on a manual, can you manually probe the wire and see if you are getting a linear 0-5V progression as you open throttle.

It would help to know if this gearbox is fitted with a kickdown cable to control line pressure or if its computer controlled

[Nic_A31]

Thanks for reply dude.
Same as R32 Skyline auto's. Solenoids to shift gears, i have no idea how the f**k they work in these gearboxes.
The second gear take off isnt soo suprising because the transmission has a "snow" mode (active when hold is on at a standstill) it will take off from second, the odd part is why it stays in second and third gears when it decides (against driver's will) that its going to use that mode regardless of the switch.

I've narrowed the problem down to somewhere in the wiring between the throttle position sensor and the crank angle sensor (which on the SOHC heads (20E/30E is located inside the distributor).
when you wriggle the connection you can hear a ticking somewhere around the TPS, and it will also toggle a buzzing somewhere up at the firewall
ALOT quieter inside the car, so its definately engine bay, sounds down low and in the middle, which again points to the gearbox, as there are no relays or even wiring in that area). This buzzing also only occurs when ignition is ON.


I've cleaned both ends of the connection on the CAS and it persists. although it takes alot more fiddling with the wiring harness to toggle the loud buzzing on, the 'clicking' at the TPS is still just as frequent.
I've replaced the TPS with the one off my other Cefiro and same deal.

Same deal tonight with the motor running, it ran fine for 5+ minutes, I gave it some stick, it misfired heavily then idled very rough, before cutting out over 45~ seconds, i turned it back on, it had a slightly lower idle, adjusted the TPS and it idled fine for well over 10 minutes (then I turned her off)

Have replaced O2 Sensor in exhaust (wired up a 3 wire sensor in place of the factory single wire) but still have a feeling its CAS/wiring related for obvious reasons. Was unable to start motor to test O2 Sensor because battery had gone flat, so will continue that tomorrow.
there was an odd smell when I was swapping out the O2 sensors....possibly clogged cat convertor ?

CAS is on the way in the mail, I'll replace that and see if that does anything.

Any idea's ?

[joshg123]

To prove a point obtain a variable resistor from dicky smith or something, put it on your 5V input to TPS wire, create a 25% load with your variable resistor and send that signal to the trans ECU (at the ecu plug) . See if your trans shifts correctly (drive at low load). If it does you know you have a glitch in your TPS's signal telling the Trans ECU that youve got your foot down further than you do or its giving it a WOT signal, or a wiring fault (notice how auto TPS's are different to manual TPS's for this reason). If the vehicle doesnt have a kickdown cable the computer will tell the solanoids to shift pressure around the box, so you can now eliminate this down to a serious box problem or a signal issue. Youd want to eliminate the easiest first

Anyway of viewing current data with a handheld OBD scanner on your car?

If i had this problem, thats the next step id take to prove the area i need to be looking in.

- Edit, actually reading your post helps. - Does the IAC and TPS share a common power that could be being interuppted when you wiggle wires?

[Nic_A31]

Its an 88 model, so no OBD unfortunately
ECU diagnostics returned 5-5 ("no fault/malfunction recorded") so all sweet there, even after a few resets.
Can't access Auto Transmission diagnostics for some reason....funny enough, auto diagnostics relies on both hold and power lights to display fault codes, so I MIGHT be able to access diagnostics on a startup where it decides it wants to use the power light.

I'll get stuck back into it tomorrow and see if I can work out where the buzzing is coming from. Hopefully just a dud connector on the CAS (also supports why it sometimes cuts out after warmed up, common for drying CAS's)

[Nic_A31]

OK, poored some money in but made no progress.

Replaced:
Distributor
CAS
Leads
Ignition Coil

That ticking/clicking sound has disappeared.
Buzzing sound is still there, and is definately transmission (disconnect transmission computer or leads 9engine bay fuse box -> gearbox) and buzzing cuts out.

Have noticed the following:
Turn key to ON, if buzzing starts, POWER light on dash emmits, indicating that gearbox is in its mode where it will use first and fourth gears
IF buzzing is present, starter motor will clash teeth, rather than turn (even if you let it stop turning, and try again it will do this...you need to turn key back to off, then back to ON and try again).

When turning the key, first few cycles sound strong, and engine ALMOST catches on, but after a few it sounds/feels like the something is resisting the flywheel, starter slows down and sturggles to turn (not battery related as I'm using a brand new battery and does the same even when you're running off jumper leads)

Idea's ?

Need car going desperately :(

[Zuicider]

a long shot, i had sumthing simular . Ticking / rattling noise coming from the flexplate area of a vn lexcen i had many years ago. would be able to drive for a bit then the car would stall or i would lose power with the engine on . Ended up being the top of the flexplate bolt holes being sheared . so the flexplate would spin free ocassionally from the crank. *shrug*

[Nic_A31]

Yeah but I can't even get engine started now.

My bad should have included in last post.
Originally would fire up and idle fine for a few minutes then die, gradually few minutes turned into a few seconds...as of last night will no longer start at all.

[Zuicider]

would be worth having a look at the flex plate / flywheel . in the vn it was alright at first but quickly became worse to the point of over 4kms between suburbs it would stall 8 to 10 times. if you have an inspection cover between the motor and box shine a torch up there to inspect the flexplate.

[Nic_A31]

Cheers mate, will check it out and update here.

[Reverb]

Not a timing sensor(crank or cam) issue as to why the car is not starting now?

[Nic_A31]

Negative...after I replaced the dizzy and CAS I had the motor running for about 60 seconds on each start....although as before, it would misfire when you gave it boot after it started playing up.

I did also replace the oxygen sensor as well, but that's obviously made no difference.