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Author Topic: GOVENOR MOD - method with lots of pics  (Read 13491 times)

February 08, 2010, 05:22:52 am

regcheeseman

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GOVENOR MOD - method with lots of pics
« on: February 08, 2010, 05:22:52 am »
Back again - all new. I originally completed this post using the old prescibed method as previously advocated here and on the vortex amongst others.

However I'm now a fully paid up subscriber to the 'only modify the main spring' club

I thought a series of annotated photos may help - feel free to chip in!



The AAZ pump; there are at least three variants of this pump distinguished by the LDA or lack of it - basically if it has a domed top it's good, a flat top or no LDA is not so good.


The other side of the pump; the max fuel screw you turn in to get more fuel - more fuel equals more power but you will hit a limit where it smokes a lot or the engine starts to rev too high. If it revs too high you can back off the minimum throttle stop screw to return the idle. There is a limit where an acceptable idle speed cannot be obtained. An EGT (exhaust gas temperature) gauge is a good idea as too much fuel causes heat which can cause serious engine damage, 800 C is a sensible maximum pre turbine EGT.
When you go for the MOT - back out the fuel screw and you'll sail through the emissions test  ;D
The screw does not need to move much to have a big effect, so move it 1/4 turn at a time.



Start to remove the throttle arm assembly, work carefully and when you get to the stage below, take a picture or mark the throttle arm’s position relative to the line on the top of the shaft - BEFORE you lift the arm off the splined shaft or it'll all go wrong!

This is the AAZ one


This is a GTD one, strangely already centre punched for me


Here you can see the spline, also note the rubber spacer and spring positions
I've also removed the throttle cable bracket to get access to the pump top retaining screws.


Work in a clean area and lay everything out in order. This is the complex double sprung assembly, the GTD may be different and much easier to dismantle.


Undo the four Allen head bolts - this one is tricky but doable with a ball ended key - otherwise remove the adjuster screw after noting it's position


As you remove the top you have to push the throttle shaft down - it can be tight-ish and need to be twisted back and forth as it is moved down out of the housing. Unhook the return spring when you can get to it.
Lift the top away, leaving the throttle shaft and governor spring assembly in situ.


Note the max fuel adjustment screw and the max throttle limiter plate - these will cause you aggro when you come to put the pump back together - 1.6TD and GTD owners do not have the throttle limiter plate which makes it easier.


Back off the throttle limiter as much as possible - for a neater job and easier assembly I'd recommend ripping it out of the AAZ and fitting a bolt, all sealed up with chemical metal / JB weld or similar.


The governor spring assembly has slots on it's shaft so it can be removed


I'm measuring the main spring gap and they all vary, the other spring is known as the intermediate spring.
The idea is to add preload to the main spring. 3 - 6 mm seems the norm


The spring assembly can be removed in one piece, compress the spring and pop out the end retainer, slide the spring assembly down the bracket and lift it out at the two slots. NOTE the GTD has a large idle spring the AAZ doesn't normally.


The circlip removed and the whole lot laid out carefully in order


I use a M6 washer and two thin M5 washers, which gives approx 3mm preload, fairly conservative and can be doubled at least should you desire.


Note the o-ring on the throttle shaft, this can often leak and has resulted in many expensive pump rebuilds for people to scared to open their pumps up and replace a very inexpensive part.
The return spring can be hooked up at this point - the GTD doesn't always have one


The hardest bit of the entire job is refitting the top... the top has to be fitted at an angle, first guide the throttle limit plate under the governor spring assembly, then ease the top on a bit further and push the throttle shaft up into the housing slightly.
Now the top housing is stuck on the max fuel plate which has to be pushed forward (the spring is pretty strong)
Once clear the top will go on a bit further and the throttle shaft can go further up in the housing
The top will now snag again as the max fuel screw hits the max fuel plate - you need to carefully get a screwdriver or similar in the gap between pump and top housing and push the plate forward again until it clears the adjuster screw and the top sits in place.
I now normally lift the top from the other end of the pump and peer in with a torch to check the governor is still in the slot and the return spring is still fitted.


Throttle arm reassembly can be tricky but as per Haynes manual - reassembly is SIMPLY the reverse of the dismantling procedure  ::)

On an AAZ the throttle return springs can be hard to fit, I tend to fit the first one in a un-tensioned position with the arm half way on the shaft, you can then swing the arm in position and tension the spring at which point there's an almighty twang, you lose an eye and four essential pieces become victims of the phenomena known as 'fridge suck' and disappear into the darkest recesses of the garage.:D


Remember to line the splines up properly and all should be good.

I normally dial in 1/4 turn on the max fuel screw at this stage too. :thumbs_up

There you go. Job's a goodun. :thumbs_up

« Last Edit: February 08, 2010, 05:28:31 am by regcheeseman »



Reply #1February 18, 2010, 01:15:24 am

goon

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Re: GOVENOR MOD - method with lots of pics
« Reply #1 on: February 18, 2010, 01:15:24 am »
great write up this will help alot thanks

 

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