Auto gearbox won't change up

[pongobongo]

Using dexron III, all correct levels and what not.

The new box was fitted by a bongo garage - no leaks etc.

Stumped.

Could it still be the ecu?

[mikeWalsall]

Have you got a chipped speado to convert it from kph to mph ..??

These have been known to 'muck up' the messages to the gearboxes ECU .. or in some cases the speedo converter not fitting the relevant wire into the ECU ..

[Simon Jones]

Could it still be the ecu?

Absolutely. Might be worth checking the part number from yours and sourcing a matching replacement from a breaker. You'd have to be really unlucky to have the same fault on the replacement gearbox.

[rita]

pongobongo, before you start chucking more money and time at this problem Guessing what is wrong (no offence to anybody meant) it would probably be worthwhile having your local Auto Transmission Specialist having a test and giving you advice.

Good Luck.

[pongobongo]

Cheers all for your help. Managed to source to source an ecu for £20. Worth the risk for that.

As for dropping to a transmission specialist - I did on the 1st box. The garage said it was the high clutch without even driving it....but a rebuild would be £1400!! Quite obviously not - due to the same probs.

Will update next week.

Thanks again.

[mikeWalsall]

As the old and 'new' box have exactly the same symptoms it would suggest some amiss with the car itself ..

Many years ago I had a 2.8 Granada estate where the gearbox suddenly had a mind of it's own .. some days perfect .. others not doing the right things ..

Fluid was fine so I assumed it was the box so I changed it for a 100% known to be good one ..

Bugga .. exactly the same symptoms with the 'new' box .. went over the engine / box / plumping ..

The only thing what we found was a perished / cracked end of rubber vacuum a pipe .. snipped a few mm off replaced it back onto the valve .. problem cured ..

We replaced all the small bore rubber pipes with a roll off all black .. May have been awkward for the next owner as the original pipes have Red / blue / yellow etc: stripes moulded in so they can be re fitted back 'to the book' ..

[Northern Bongolow]

have you measured the out put of the alternator if the voltage is wandering all over the place especially when is been warmed up it could be this, or the sensor above the starter motor in the side of the head, this sensor tells the ecu what the temp is,so allows gear changing, admittedly only top cog but if this is wonky it could cause all sorts of weird things, but check the alternator first.

[pongobongo]

Thanks all. Will try measuring the out put and check the hoses. Will drop ecu in on weds and let you know.

Are there any diagrams/pics available for the pipes/hoses? It's like spaghetti junction down there! Haha.

Ta

[Muzorewa]

http://www.igmaynard.co.uk/bongo/member ... /hoses.pdf or go to the Lushprojects site http://lushprojects.com/bongopartsmk2/

[pongobongo]

Well.... The ecu has been changed. Immediately I noticed it was much better. No slippage.

Engine warmed up - and slip!

However, turned ignition off for 5 mins, and it worked again. Seems as though disconnecting/powering down the ecu reset the system (?!?).

As for hoses - all fine.

Argghhhhhhh - stumped.

[Simon Jones]

Ok that's progress in as much as its different and it seems powering it off and back on may be of some significance. Have you had any electric work done on the van such as fitting a leisure battery or switching things like blinds over to an existing leisure battery? I came across a vehicle which has had the LPG conversion wired to the LB which is clearly a daft thing to have done. I'm wondering if there is something affecting the voltage or signals to the ECU.

Alternator output ok: not too low or too high?

[Northern Bongolow]

did you check the alternator output voltages when cold and warmed up and reving etc.

19-444 on this link, its a temperature inhibitor switch. check the wiring for damage,or maybe get a second hand sensor to try. if you click on the number on the drawing it tells you the part number and what it is in the the left margin.

http://lushprojects.com/bongopartsmk2/c ... o=.html#14.

[pongobongo]

Haven't been able to check alternator yet. What output are we looking for?

The bongo does have a leisure battery installed; I haven't done any electric work on it tho.

Whilst installing the ecu today, I did notice lots of unconnected wires in the passenger footwell. Hmmm. Also, pulled out clocks - no chip. : (

Many thanks for your help.

[Northern Bongolow]

you want a good 13v when ticking over and up to 14.5 when lights/heater on etc. if its down at 12 or at 15v then the diodes could be buggered, it needs to respond quickly when load is on and drop when not loaded.
a duff alternator is well known to affect the operation of the gearbox.

[pongobongo]

Thank you. I'll check it out this weekend.

As for the inhibitor switch, Im uncertain if one was connected to the replacement gear box or if the garage used the switch from the old box. I'll ask them.

Thanks again.