AAZ rev's don't always drop when I take foot off gas

Post by **skell** » 19 Oct 2006, 19:34

Just got a velle fitted with an AAZ, revs don't always drop of when I take foot off gas, haven't had chance to look under lid yet, any ideas?

Post by **Sir Chad** » 20 Oct 2006, 15:58

Hi Skell,
could be sticky cable or weak spring, for starters.
Chad

Post by **skell** » 20 Oct 2006, 18:50

HI chad
how's yours going?
I've now got two, oil burner is a daily...came with some nice rims and dire need for a good srubbing with wet and dry!

Post by **skell** » 22 Oct 2006, 15:27

sticky cable and weak spring eliminated from enquiries, what next?

Post by **skell** » 23 Oct 2006, 18:00

think i've found the problem (defo found a problem anyway), when AAZ was installed turbo oil drain wasn't moved from block to sump, looks like I've inherited the n/a sump. time for a quick search for a sump.

anyone know if I can change the sump without dropping the engine? looks possible.

ta

Post by **Sir Chad** » 24 Oct 2006, 13:28

Hi Skell, here's some food for thought...
would it be possible to modify your existing sump? I'm not familiar with your engine but I've done it on non VWs before, gladly give you a hand if you need it. Sump off job though.
My GTi swap is getting there (steadily), recently had to cut a big lump out of the chassis, to clear the inlet manifold, all I've got left is wiring to the ECU & fuel pump and then Exhaust pipe fabrication.
Chad

Post by **Russel** » 26 Oct 2006, 11:29

The revs not droping has nothing to do with the sump.It is recomended
to have the return going into the sump but not critical.(can cause oil buildup if not to sump)
Ure problem is probably someone messing with ure idle richness screw on ure diesle pump.If it is to rich it will cause these problems.

Post by **Sir Chad** » 27 Oct 2006, 15:10

Hi Skell,
if you can't solve your overrun problem give these guys a call, they're local to us and would be able to help...
Brighton Auto Marine Diesel 01273 415296
2 St Leonards Rd, Hove.

Post by **HarryMann** » 27 Oct 2006, 17:00

anyone know if I can change the sump without dropping the engine? looks possible.

Yes, you can if you want to, just be careful with all those set-screws, and make sure the sumop is up there and set screws are nipped up before tightening the bellhousing through bolts

Post by **Simon Baxter** » 27 Oct 2006, 20:07

Russel at Syncro-Nutz wrote: ...Ure problem is probably someone messing with ure idle richness screw on ure diesle pump.If it is to rich it will cause these problems.

It's not an idle richness screw, Diesels are throttled by fuel, if it were to be rich it would be revving high, the screw in question affects fuelling all the way up the rev range.

But, if the fuel screw is wound in too far the engine will probably go like f**k, black smoke, and the revs do take a while to return to normal, if it returns at all.

I would check your throttle cable bodge to make sure the throttle lever is returning to it's stop first.

The oil return won't make it run fast, if it starts burning it's own oil it will be revving it's nads off, making horrible noises and smoking more than a beagle. I know, I saw the guys from the Renault garage across the way from where I worked at Nissan sit back and watch a Scenic destroy itself!

Post by **Russel** » 28 Oct 2006, 19:30

If that screw is turned in it will pick up the revs BUT if the throtle position skrew is turne out this will reduce the revs again.At this point if done to much it will display ure symtoms,The discription i gave was written in words for the not so mechanicaly minded to understand.Not for others to try look better informed.And if u want to affect ure feuling proply through the rev range u need to do a bit of machining not turn a screw.

Post by **Simon Baxter** » 29 Oct 2006, 17:46

Russel at Syncro-Nutz wrote:If that screw is turned in it will pick up the revs BUT if the throtle position skrew is turne out this will reduce the revs again.At this point if done to much it will display ure symtoms,The discription i gave was written in words for the not so mechanicaly minded to understand.Not for others to try look better informed.And if u want to affect ure feuling proply through the rev range u need to do a bit of machining not turn a screw.

Heh, not after an arguement...

....but that is the fuel screw, the revs increase because the fuel has increased, like you say if you back the throttle stop off then the revs will drop, because you are again backing off the amount of fuel.
The fuel screw isn't affected by the governor, the throttle spindle is.
Have a look at a cross section of a fuel pump and you will see what I mean.
Increasing the amount of fuel through the rev range, the fuel screw will do this, as will fitting a bigger head and rotor, going from 9mm like the 1
.6TD and the 1.9TD up to a 10mm, 11mm or 12mm as some of the nutters are doing!
Fitting a bigger head and rotor will let you run more fuel, but with the fuel screw backed off resulting in a pump that isn't "Maxxed out" and returns to idle as it should.

As it happens Im just building a pump for a AAZ with a 10mm head and rotor and a different pump top to allow more "Messing"!

I would be interested to hear what you are machining Russell, is it the LDA on the 1.6TD? I've seen how Oettinger modify their pumps and it's not pretty!

I've been looking at the LDA of the JX pump, seeing how I can get more fuel on boost as the LDA seems to run out of movement at not much above .5 bar, if I could double this then it would be nice to fit JX pump tops to AAZ pumps and have the best of both worlds, a pump that lets you add more fuel according to boost and one that fits under the engine lid and one where you can adjust the boost and the LDA will be able to cope..

Post by **skell** » 30 Oct 2006, 18:02

Throttle is returning to rest ok, so next step is to try backing off fuel screw a bit?
If this gets me nowhere I'll get in into see my local tame veedub garage.

I'm keeping oil level bang on and taking right handers slow until I've swapped the sump (and manfold) for the JX one, and just pottering round town now and again.

Simon thanx for the studs, nuts and AAZ fitting kit sent this week, arrived the day after you posted it, van is looking the mutts in its 16" Audi rims

Post by **HarryMann** » 30 Oct 2006, 18:48

Isn't there a screw down the LHS (camcover side) that's almost unreachable on these that does something to the idle fuel flow? Made a small difference to mine, after a ten minute struggle, but sounds like you've got more than one problem there...

What a dog's dinner some of those injection pumps are, anyone know a good source of exploded diagrams of 'all' VW injection pumps - 'cos mine can join the list

Post by **Simon Baxter** » 30 Oct 2006, 19:40

skell wrote:Throttle is returning to rest ok, so next step is to try backing off fuel screw a bit?
If this gets me nowhere I'll get in into see my local tame veedub garage.

I'm keeping oil level bang on and taking right handers slow until I've swapped the sump (and manfold) for the JX one, and just pottering round town now and again.

Simon thanx for the studs, nuts and AAZ fitting kit sent this week, arrived the day after you posted it, van is looking the mutts in its 16" Audi rims

Does the van go like f**k and black smoke?

Glad parts arrived okay and hope you understand what all the bits are! fairly slf explanitory!