2001 Estima Owner

Update: had a mobile mechanic check her over and he found filthy spark plugs, and after he cleaned a sensor (air? fuel? not sure) the car ran fairly decently. So he thinks Ive had bad fuel, which may or may not be the only problem. He said he's never seen such crud in a system. (So I hope the guys I was paying to for my servicing were actually checking things all these years). At least Ive got a starting point. Next step: drain fuel. I couldnt put a hose down the fuel tank, so Google tells me using the fuel pump is the next best thing. Im looking for the fuel pump relay. Apparently I can jump that with a wire. I just need to find it. Is it the main EFI relay in the engine bay, or do I need to find a secondary one elsewhere? Once drained, I can get her to a mechanic for changing of the rest. Hopefully.

Update: van no longer runs. It starts and idles fine, but any attempt to use accelerator causes wild backfiring, strong fuel smell, and engine splutters and dies. No way to increase the revs without this happening. Nothing seems to have caused this; it started shortly after having the diagnostic by the auto electrician. He said all he did was check the error codes and reset them, and that couldnt affect the car in any way. I guess the plan now is to wait and see if my original mechanic can find a management module, and hope that does something. I was going to take the vehicle to a mechanic I found who specialises in imports, but now I cant move the car (and he wont come here), that plan has gone out the window. I suppose towing is an option.

I have mentioned all the above to my mechanic, and he thinks the transmission management module (or whatever it is called) could be the culprit I think he is trying to get a replacement to swap it out and try. My dad thinks a high voltage cable could be to blame. Thanks for suggestions so far.

Trying higher octane fuel is the next thing I am going to try. Someone recommended it. No sure which fuel it is supposed to use; I bought the vehicle imported and it didnt come within any instructions. Ive always just used the most budget unleaded, but not had a problem for the last 8 years or so. I mentioned this to a mechanic and he says it would be better to use good fuel, but can't be the only reason it is acting so poorly. He thinks maybe the engine management module is faulty...so Im looking into sourcing one, if possible.

Update: Van now only drives up to 80km/hr, then accelerator no longer works and van drops speed until 60, when accelerator begins functioning again. This happens about every 10 seconds, so van is now not very driveable in its current state.

So my Estima's automatic transmission won't go into top gear, and starts getting high revs above 80. The check engine light is on. I talked to a transmission guy, who said go see an electrics guy (because from his experience electronics go before the actual transmission), who ran diagnostics that came back with "knock sensor 1 and 2". So it seems because the engine isn't running perfectly well, or the sensors are just thinking it's not running well, the system is hampering the transmission...not sure why. Electrics guy says next step is trying to replace the knock sensors, and I suppose also getting the engine to run better (it's pinging a bit and also a tad sluggish, but nothing outlandish...I mean it seems to be running well as far as I can tell). I dont really understand how all this is related, but someone has told me it's feasible either faulty sensors or just low-power from poorly running engine can cause the engine management to start disabling things. Who knows? (not me!) So any advice would be appreciated. I love the van, but it seems like a rabbit hole of finding and replacing sensors and things, which will be hard to find anyway, and crossing my fingers it works. Could I sell the van as is, to someone who doesnt mind a slow van? I doubt it, but the car market is crazy nowadays. It's in top shape otherwise. Do I scrap it? Seems like a big waste. Then I need another vehicle. Or are knock sensors easy peasey when you know how? Wow. It's a quandary. Anyone have experience or know-how?

Thanks. Much appreciated. Think I've got my head around it now. Cheapest transmission I can find is $2250 (with 150,000kms), which I'll need to bring from East over to WA, then $1200 to have it installed, plus fluid etc. Not sure the Estima will make it through this one...

My mechanic says I need a whole new transmission (overdrive stopped working). There arent any available via whatever means they normally use to find such things, but Ive found in the past that certain parts are compatible with other more-available models of Toyota etc. Would anyone happen to know if this is the case with the transmission of my 2001 MCR40 Estima van? Any other cars that would match? The transmission on the plate is "U140F" (with "03A" after...not sure if that is relevant.) Cheers in advance, Mike