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91 n/a auto has a problem with the auto box not changing at correct point much too high also on occassion engine at idle will rise to 1500rpm or so on its own.

 

Had auto box itself checked by local specialist who said box itself was OK, have also fitted new tps with no effect.

 

car was put on diagnostics and it seemed to be getting a spurious reading to the speedo & ecu even when tps unplugged

 

car has been fitted with speedo conversion at some time also this problem has gone away once and is now back, when box changes at correct point the car is a joy to drive.

 

The problem seems to be the signal to ecu maybe being corrupted and also has something to do with occassional high idle

 

Any ideas or do you know anybody in Broadstairs Kent area who could help

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deffinatly sounds like you need a conZult session, im pretty sure this would reveal the problem quickly without guesswork and wasted money, danny is doing them at billing next weekend for 15 quid, get yourself down there! :)

but car is not driveable in present state more than a few miles, where is Billing anyway??

near Northampton. Undrivable? Sounds like a more serious problem tbh if its undrivable.

In a lot of cases what the "speedo conversion" does is rob one in three of the signals to the speedo/ecu hence converting the signal to mph and fooling the ecu chip that you are doing 2/3 of the speed you actually are, "raising" the speed limiter.

 

It is possible that the speedo conversion has an intermitent fault as they are prone to do, which would cause your spurious speedo reading.

 

Do you know where the wiring for the speedo conversion is? if so can you remove it ?this will put you back to restricted and km/h, but will tell you whether the conversion is causing your problem.

Did they change the transmition fluid correctly is there a leak? sounds like there might not be enough pressure on the lines, and thats why its changing laggy although that said this is a complete guess and could be totaly wrong lol.

 

When you put your foot down does it seem like it slips before engaging / changing.

No the car seems fine when the box is changing ok but then this problem comes back, I'm sure its a problem with the loom or more likely a sensor.

 

What other sensor apart from tps effects auto change point and may also cause a high idle problem

 

Note: high idle problem -- when idle ok, box still has change problem also since this is import I can get box to behave a bit better by selecting hold on switch.

have you found what was causing the TPS fault logged in the auto box ECU then?

No, Terry Mead had car for a few weeks and came to conclusion that box itself was ok and that after all it was a tps fault because he was getting incorrect readings, thought that because your tps is manual that there was difference on auto part (more pins) anyway replaced that and car was fine but 3 days later bloody thing did exactly the same fault.

 

Seems to be getting strange readings to ecu from something other than tps causing gearchange to cock up suggesting a electrical fault not a gearbox fault, only problem is nobody around here wants to touch it.

 

If you fancy another go please contact me, I never did hear anything from your mate.

 

Regards

 

Mike

so the fault memory in the gearbox ECU is clear now then? (im sure the TPS was the same for auto/manual??)

The TPS needs to be

A) working

B) correctly adjusted

C) have a good signal to the ECU(s)

 

Just swapping it for new only guarantees A.

 

Google for how to do B (quite easy - you want the black wire and the white wire if confused - or do it with conZult).

 

Harness somewhere between TPS and t'other side of the firewall may be dicky thus C not the case.

 

I suspect B... because if it's not correctly adjusted you won't get the hard idle switch triggering when idling and hence high idle.

 

And check throttle cable for slack...

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