Taxi Driver Online

Its the vacuum controled one,as i said im no expert on setting them up.I dont think you could do away with the kickdown on that gearbox .But if its not running right it might need setting or possibly theres a seal that goes thus the pressure isnt right .On another note have you changed the fluid in the box ? It can make a difference

The fluid does not look new but it does look fairly pink and the level is good so I'm not going to panic on that front.

I'm still wondering if that broken vac hose pictured earlier has any part in any of this?

I dont know but if its broke id try it,is it hissing or any pressure on it ? If theres any auto specialists in your manor might be aswell to let them have a glance.As i said earlier if the seal has gone and its not getting the right pressure to create vacuum it might be a easy fix. Good luck

It's just a bit of old hose sitting there on the side of the engine. Goes to nowhere. In theory at idle there should be a good bit of vac at the air filter housing where the engine is drawing all its air to run. In practice on my one it could be blocked but not really looked that carefully at it yet.

Diesel engines produce virtually no vacuum whilst running which is why they have a vacuum pump fpr servo assisted brakes.

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Selling Imperial tools for old cars.

did not know that. not very good with diesels although I have fixed a couple of problems on it already.

Hello
Type "Jatco E4N71B vacuum modulator" in google. There is some info on various pages (the one detailing a box swap on a Studebaker is pretty detailed) that may help.As I understand it a valve on the injection pump is worked by the throttle setting and alters the amount of vacuum applied to the modulator on the side of the gearbox which in turn alters the pressure inside the box.
The pipes you can see which have broken are the pipes taking clean air to this valve and would have no effect on its operation but a leak the other side presumably would.
There's plenty of info on the pages,hope some of it helps,I'm familiar with the older Borg Warner boxes but know little about these.Let us know what you find out.

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Selling Imperial tools for old cars.

Its usually the seal/diaphram that perishes on the valve on the pump that causes problems on the gearbox,fixable though.

Well the good news is that the taxi appears to performing fabulously.

I've just completed a 100-mile+ trip and it went well.

On the motorway it no longer kicks down while cruising. The speedo overreads by about 5mph. On the flat you can keep it going at an indicated 80mph. Down a hill I know you could hit 90 but the wheel balancing, tyres and other aspects of the vehicles dynamics make it a really bad idea so didn't push it that far. 80 is hard enough.

Going uphill is still a struggle but I did have 3 passengers and their luggage so would consider that fully loaded. Up a hill the speed drops to between 60 - 70mph.

Only thing I find slightly troubling is the amount of smoke it makes on full throttle. I know taxi's do smoke and so do diesels so I'm not going to do anything about it but I find it slighly amazing.

If its been doing a lot of town driving maybe its a build up of soot. Blowing it out on a motorway run will probally help a bit.Have you changed filters recently ? Anyway glad youve got it running well, good luck

90 mph in a fairway?
Rather you than me

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Selling Imperial tools for old cars.

I did not take it that far. About 80 was as much as I dared. Was getting shakey, drivers door beginning to open, lots of smoke, engine temp going up. I know it would do 90 down a hill but like you say... not a good idea.

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Think of how stupid the average person is, and realize half of them are stupider than that.
George Carlin

Have you tried some injector cleaner additive in the fuel? That can make a world of difference.