Bongo Fury

Recently aquired a bongo with low mileage and in good condition but left for a few years

Finally got it started fiddling with banjo and new diesel filterand it ticks over nicely....and pretty much everything works
but
throttle not doing anything initially and now has an effect mostly as beginning to push on the pedaland then seems to not increase (possible drowning)
trying to get a tps off another vehicle but last bottom connection impossible to get at.. any tips
also
when moving gear selector from R to P getting a clattering teeth sound.. and not sure if any gears are actually engaging.. but its the R to P which is alrming at the moment..
Have discovered leaking pipe or pipes underneath .. viscuous oil reddish substance... think one pipe is for the power steering fluid..the other leads to the transmission box.. its a lowwer pipe... is this transmissionfluid..or transmission coolant fluid..
any response or thoughts welcome...

hoping tps is the throttle problem..and that low fluid pressure is affecting the change from R to P

many thanks

There are two long pipes from the gearbox right to the front cooler radiator, if one of those are leaking then you probably don't have adequate gearbox oil! Have you dipped the gearbox (use the right method - engine running and warm then run the thru the selector, before dipping with the gearbox dip stick under the drivers seat) it sounds like you may have lost your DEXRON III gearbox oil!!

Thank you, this is what I am hoping... soon find out.
Any thoughts on how to free up a sticky throttle position sensor. the vehicle has been sitting a while. i have a salvaged spare tps but one of the connections is a nightmare to get at, and i would rather reinvigerate the present one. Most of the vehicle is in fantastic condition and low mileage. SO it might just have gotten a bit 'crusty'? inside. There is a throttle response, but very minimal.
All insights welcome, looking to learn.

Question: Is there a limp mode related to transmission fluid loss, that might restrict throttle use? a long shot...

Not directly, but loose a lot of oil and temperature will rise which will trigger limp mode and I suspect other things!!!

what year is the vehicle?

year of bongo is 1996, 75k on the clock whther thats miles or kilometers not sure... so much is in good order