auto gearbox issue isuzu bighorn 94

[Estirl]

hi everyone first off i am new hear and not great with computers so sorry if this is the wrong place
i got an old bighorn 94 lotus edition import 3.1 d lately when going to overtake or accelerate from say 40 mph to 60 mph she seems to be slipping down the gears erratically but with no real acceleration. also i noticed when cold she takes about 15 minutes or 2 miles running before she goes into top gear and twice now the reverse has a delay before kicking in. automatics arnt common here in northern Ireland and good mechanics are harder to find as most wont tuch auto boxes any ideas. i need my car running well she covers 60 miles a day to work and back getting rid of her is not an option.... ever!!

[dubdubdub]

could this possibly be the tps sensor?

[Estirl]

duno ! how do i test for it . i was looking on the net for similar issues wondering if maybe it could use o good service some folk recon it could be low on fluid. hoping its something simple.

[dubdubdub]

well absolutely, I would flush the whole auto box to start with and see how that goes, make sure you get all the crap out with a proper flush as allot of shitty oil gets held in the torque converter, and just draning the box and topping it back up wont do anything. a proper flush is required then look else were.. defiantly start at the box flush. Not to sure how to test tps but apparently they are a problem on the auto's and cause allot of kick down.

[geeves]

"15 minutes or 2 miles running" ??? Your traffic must be fun
By design the auto will not go into lockup mode until the transmission fluid is at a certain temperature and also the engine. If your engine thermostat is stuck open it will affect how the auto works. Mine wont lock either for a similar distance but as I live on top of a hill all roads go down.
The description of how its changing does sound like slipage though which isnt nice.
To check your fluid you will find a dipstick just behind the engine dipstick on the left side of the engine bay. To check the fluid first start the cold engine and with the engine idling cycle it through the gears holding each gear for about 10 seconds and place in park leaving the engine running. Remove the dipstick clean and replace to get a true reading when you remove again. There are 2 marks on the dipstick. The fluid should be on the lower one. The fluid should be a clear medium pink colour. If it is a straw colour it is ok but due to be changed. If it is dark blood red or brown and smells like burnt toast the fluid is burnt and must be replaced. Unfortunately often when the fluid is like that it is due to internal failures in the auto and a rebuild is the only fix. Now take the car for a 12 mile run and recheck the fluid as above but now it should be on the top mark. If it is candy floss pink and frothy it has water contamination. You must change all fluid and fix the source of the water. Once again gearbox damage is very likely.
The tps is on top of the diesel pump. If you can get an analogue multimeter it makes checking easier but it can be done with a digital. Conect to the middle wire and earth and note the voltage as you press the accelerator. The voltage should climb steadily in the 5 to 8 volt range

[Estirl]

thanks guys for the help and advice will look at it this weekend and keep you posted
traffic is all farm roads narrow and bendy usually full of maniacs who are late for work the trick is don't take prisoners!!. last year some clown was speeding and drifted across on the bend, and totaled my mondeo hence now the the big 4x4. if it happens again i'm getting a tank

[Estirl]

HOLEEE _ GOD... there's not a stitch of oil in the transmission. how this yoke is still running is beyond me. living proof of isuzu durability. any way i gues thats why its slipping so shes getting some long needed dexron. hopefully there's no damage done.

[geeves]

I think the chances of no damage are not high