Automatic: Engine races on start up after trans fluid change

[Cakewalk]

1981 Aircooled Automatic

Changed automatic trans fluid and final drive oil in prep for long journey to Devon in a couple of weeks

Since doing this though, whenever the van has been stood for as little as 10 mins, the engine races like mad on starting up for about 30-45 secs.

Really disconcerting cant be doing it any good

Engine returns to normal idle if you blip the throttle after about 30-45 secs as mentioned and then drives as normal.

Its not the choke sticking on - have checked and the revs are too high any way

Trans level is fine. Checked it how you should by going for a 2-3 mile drive and then checking with engine running in D or P

Is the box on the way out? anybody encountered this symptom before?

Should I change the fluid again? - used Dextron II last time

Cheers in advance

Ben

[Rozzo]

sounds to me like the throttle cable has been disturbed or is seizing up. the oil wouldn't mek a deal of difference to the engine speed i dont think

[Cakewalk]

Ok - so ive dropped the fluid again ( for the sake of £15)

Refilled with new Dexron II

Same problem - Start van, engine revs gradually increase until engine is racing (about 2500 revs {est}). Returns to normal idle after 30-45 secs

Its not the accelerator cable cos ive stood round the back and made sure the carb linkage is definitely closed

Its ok if you leave it 5 mins or so, it will start as it should but any longer and the problem occurs

So my (entirely uneducated) guesses are along the lines of

- one of trans valves sticking open / closed until pressure builds

or my current theory

- tourqe converter emptying of fluid when van is stood = massively reduced resistance in converter on start up = 'runaway' engine until pressure builds and fills conveter up = return to normal

Its doing my head in now

Any auto experts, help and advice appreciated

Thanks

Ben