Kahl

Hi guys,

A while ago I noticed my speedo was taking a while to "warm-up" and read correctly when I would start driving the car (1992 ucf11). I had a browse around on the forum and it looked like it was potentially one of two things, either my dash was giving out or a sensor on the gbox was. The odo still was working.

Now I've noticed when I drive (cruising, low throttle) at around 50kph (35mph?) at times it feels like it wants to change gear (up I assume) and the car gets all jumpy, almost like a throttle cut. The same thing has been happening at around 100kph (55mph). I'm not sure if it's gbox related or not?? I was pulling out to pass and as I was trying to accelerate over 100kph the engine would not continue to rev and it felt like I was getting a speed cut or similar.

Could this be an issue with a speed sensor?? The odo continues to read correctly.

Any more information that would be helpful??? Is this the kind of thing that a Toyota service shop would be able to diagnose??

Appreciate the help

Cheers,
Karl

LScowboyLS

speedo issues + shifting issues, simultaneously, is most likely failing ECU capacitors - and '92 models are having this issue in epidemic proportions, so definitely read the thread I linked to above!

You can also pull the ECU and look for visual evidence of capacitor leakage or alternatively, you can perform Yamae's ECU ripple test

Kahl

Perfect thanks, I'll have a good read of those two threads and post in there if I have questions

LScowboyLS

keep in mind that the ECU is in charge of all transmission control - there is no separate ECU for the transmission, like in newer cars. - then it makes more sense!

Kahl

Perfect, I'm trying to make my way through the thread you linked, pretty keen to do the cap swap. I pulled the ecu and the caps looked fine but I know that doesn't mean they are fine.

One quick question though. I have a 92 celsior, ecu number is 89661-50170 I get the impression that the last 5 numbers relate to software revisions. I see an ecu out of a ucf21 available on a local (NZ) auction site with the number 89661-50380. Are the two interchangeable? I'm not 100% confident doing the cap swap and it would be nice to have a backup ecu if the unthinkable should happen to my original one.

Cheers and I'll keep making my way through the thread

Yamae

No, they are not interchangeable.
89661-50380 is for a UCF20 shipped August.96～July 97. It can be used for models after October 94 as a countermeasure to prevent the engine stop after the high speed run though.

Kahl

Ok cool I'll not buy that one then I guess I will take my chances buy the new caps and try get someone to fit them

Kahl

Just re-confirming, mine is a 92 but seems to have a 93-94 style ecu, 8 caps and the same number of pins per plug as the -50380 that is available. Still sure it won't work???

No problem if it is just want to be sure

Yamae

LOL. It's your car and I don't stop you to try but I can image how you regret doing things only seeing the capacitors number. Things are not that simple, you will know. How can you analyze those built in programs in the ROM just looking at it?

LScowboyLS

what Yamae is correctly telling you is that even if the ECU's were absolutely identical in every way in their electronic components inside, the internal software programming is very different inside the large memory chip in each one.

Twista4004

So I been readin', an studyin' tryin not to be a dummy.... I bought an ECU on ebay for about $100 so I could keep drivin while original is repaired. Local JYs were LS Barren. Good thing I guess. Our cars are still on the road here in SoFla... I've been having this slow speedo (doesn't work for first 2-3 minutes of my drive on cold start) and my trans doesn't properly engage drive until about a FULL 20 seconds of sitting in D then it will jump forward (only on cold start). I am doing the right thing in fixing these caps right?

I know the car needs it anyway but I'm hoping it will fix:

No A/C
Engine Stumble
Sticking Speedo
Slow Trans (been doing the 2 quart drain and fill on the trans every oil change. 4 fluid changes so far @ 4-6k intervals)

Car is a dream otherwise... definitely want to fix her up and make her my VIP machine.....until I get a LS 430 or 460 and start all over.

LScowboyLS

Only if YOU supplied the caps ordered via my links in post #1 of the ECU cap thread - your local guy doesn't have the correct, very rare capacitors, nor are they available a local electronics store, nor do the folks on ebay or other rebuilders use the correct rare type!

Twista4004

Ordered a couple weeks ago from Digi-Key.

Haven't checked my mail yet to see if they came in. Think I'm gonna try this other ECU and see how the car likes it before sending off.

Do you think I'm good for those other symptoms as well? I've been fighting the itch to take my car to an A/C place to have it diagnosed until i sort out these caps.

Kahl

Yeh I thought that was the case, just checking because I had seen talk about people swapping ECUs with differing numbers and wanted to understand what the boundaries of this are.

On a better note, my caps from digi-key just came in, I ordered off the links you provided in the main thread (WOW it was fast as well even at this time of the year). ALL of them are the right/correct uF number but a few are higher voltage than the ones in my ECU. I assume this is fine? Like I said, I used the links you provided so I'm reasonably confident I'll be OK but just want to confirm what I have will work.

For instance I have:
2x 15uF 63V

Where the ECU originally has:
2x 15uF 35V

I think I recall somewhere in the main thread somebody said the higher voltage wasn't a problem, again just want to confirm before I get them installed

Rad,
Kahl

Yamae

Yes, higher voltage capacitors are mostly OK. I wrote more at here.

Regarding ECUs for JDM Celsiors, I made a list below for you and those who love JDM Celsiors. As far as I know, ECUs of each block can be mostly compatible but I cannot guarantee it.

Gen.
ID Number, manufactured, Year.Month, Models used,
How changed.

Gen.1
89661-50100 89.11-90.05 for UCF1#..B,C
89661-50092 90.05-92.08 for UCF10..A
89661-50102 90.05-92.08 for UCF1#..B,C
89661-50102 91.07-92.08 for UCF10..A with TRC

Engine management changed. Cold start injectors added. O2 sensors changed to built-in heater type.
89661-50170 92.08-94.02 for UCF1#
89661-50171 94.02-94.10 for UCF1#

Gen.2 Engine management changed. O2 sensors added at the rear end of CATs. Higher compression 5HP Up.
89661-50240 94.10-95.01 for UCF20
89661-50241 95.01-96.08 for UCF20
89661-50380 96.08-97.07 for UCF20

Gen.2.5 Engine management changed totally with VVT.
89661-50450 97.07-98.08 for UCF20 VVTi Engine
89661-50520 98.08-99.01 for UCF20 VVTi Engine
89661-50521 99.01-99.11 for UCF20 VVTi Engine
89661-50522 99.11-00.08 for UCF20 VVTi Engine