Automatic leaping forward

[project25]

Hi, Anyone out there adjusted the selector rod on an auto box?
Ive got a 1984 dg 1900, when I select drive (or reverse) the vehicle either stalls the engine or charges off in what ever direction I have selected.
I bought the camper as a non runner so I dont know what is supposed to be like.

[project25]

Hi, again, Im beginning to think nobody likes working on autos, I have posted this question before with no replies.

[kevtherev]

I would rather think that they are rare and not many have had much experience of autos, is why you have had a poor response.

As I see it, with my limited knowledge and your explanation, there could be issues with the tickover speed to high, or the ATF fluid is wrong,
Have you tried a garage for any diagnosis?

[mm289]

Bit like Kev says, diagnosing slush boxes is a black art so not many have experience.

I do run auto's in a lot of our vehicles including the T25 on a 2.1, but should basically be the same as a 1.9.

When you are in any setting (PRND) revs should be reasonably consistent at (from memory) about 900 rpm. You will notice a slight drop when you go from P or N to D or R but it should not stall - defo.

Equally, the way an auto is set up, when you go to a driven gear (D or R) the vehicle should crawl forward if no braking force is applied (foot or handbrake) but the vehicle should not lurch or surge.

So, you kinda have 2 opposite symptoms. If it stalled on selecting a gear i would say maybe idle to low or idle compensator (a device that raises idle slightly to compensate for extra drag) was faulty. But if it also surges on selecting a gear that implies too high revs

Easy checks are fluid levels - real pig to get right in my experience cause all manufacturers say do it with engine running - problem is when the engine is running the fluid splashes around in the sump and you can't get a clean reading. I do it cold when it should be at the bottom of the dipstick mark.(ish)

Apart from that, idle would be my next culprit, is it idling smoothly when not in gear i.e. in neutral? Is the engine running well apart from this issue?

Otherwise you are into doing a better diagnosis really, exactly when does it occur, when does it surge vs stall etc.

HTH

MM

[project25]

Hi, Im glad I got a response, I was beginning to think I was alone. You are right about having 2 probs, cos I am having carb problems as well. Cant get it to tick over until warmed up, choke not working proper. Even then the idle is uneven.

I went to a local VW mechanic, he said the Peirburg carbs are good when working right, barstewards if not.
Sold me a scrap one for £65 (is that too much). Fitted it today, no different.

[mm289]

You might of been better spending your £65 on a couple of hours of his time to do some diagnosis on the van

If you have carb probs then you will have to sort those first before worrying about the auto setup otherwise you are wasting your time.

Your OP said you bought it as a non runner - so I am guessing you have some basic mechanical knowledge (or just like taking risks )

Do you know why it was a non runner? Either way, I would suggest you go through a methodical diagnosis route, starting with bringing electrics (points, plugs, timing etc) then fuel (air filter, fuel filter, carbs) up to a good standard. Once you know all that stuff is working properly you can then rule a lot of stuff out and start working on narrowing down the problem. To do this all I would recommend you get a Haynes manual as a minimum or a Bentley - especially if you are into rebuilding/setting up carbs.

The alternative is to throw parts at the van hoping you strike lucky and find the one that isn't working

Of course I could be teaching egg sucking to an old lady and you know all this already, but your original post is kinda vague. Might also help if you put a location in your signature, then if people are local you may get more offers of help

Cheers,

MM

[kevtherev]

Hi, Im glad I got a response, I was beginning to think I was alone. You are right about having 2 probs, cos I am having carb problems as well. Cant get it to tick over until warmed up, choke not working proper. Even then the idle is uneven.

I went to a local VW mechanic, he said the Peirburg carbs are good when working right, barstewards if not.
Sold me a scrap one for £65 (is that too much). Fitted it today, no different.

Basics first..
New Plugs leads cap and arm.
Then check for inlet leaks...
Vacuum lines
brake servo hose
split gaskets

When your absolutely sure thats all good
we'll move on to the carb

[T25daisy]

hi there ive just reading your thread and i had the same prob with a secound hand box i bought for my van and found out that someone had a play with the box before and tried to stop an oil leak on the 2nd gear brake band piston seals thats the round about 4 inc circle on the outside . but if you take it out with the box in the van it relesese the band inside and the box wont work properly . its sounds like the same thing when i put it in reverse it went back but it seemed as if park was on as well . but when you go forward there is only 1st no other gear. striped the box out and rebuilt it and it runs like new now . the boxes are not that bad to work on if you take your time with them and keep it clean inside