1.9 Diesel - AAZ with modified JX pump - Pump timing issues

Post by **mahatmacoat** » 14 Sep 2008, 19:38

Okay, continuing on from a previous thread https://club8090.co.uk/forum/viewtopic.php?t=39948

I now have a JX (Bosch VE) pump with the AAZ camplate and necessary bits fitted. This was all built by a professional and tested on a rig to an AAZ program, so should be spot on.

I have installed and timed the cambelt with the correct tools. I then had to advance the pump (turn the pump body anti-clockwise) until it hit the limit of the slotted holes and the boost actuator on the top of the pump hits the hose outlet on the side of the head. I used a stack of washers to lift this out of the way & the pump was still not advanced enough.

So I took the belt off and re-timed it one tooth advance & took the pump body back (clockwise) to the other extreme.

It now runs smoke free and revs well, but sounds like a transit van i.e. diesel knock. So it's too far advanced!!!

I've checked that the manual advance lever is not pulled out & that the pump pulley has it's woodruff key. The keyway isn't worn and I've checked and re-checked the cam/crank timing 3-4 times.

It seems I want a timing point half way between the two.

I know the ideal is to use a DTI, but wondered if anyone else had had similar problems.

Anyone else have an AAZ with a modified JX pump or anyone worked on one?

Post by **andysimpson** » 14 Sep 2008, 19:48

Having AAZ internals in the pump won't have any bad effect. I would try gravity feeding the pump and see if that makes a difference.

Post by **mahatmacoat** » 15 Sep 2008, 20:09

I realise that AAZ internals in the JX pump will be okay, I'm having problems timing the pump.

Does anyone know if the AAZ and the JX pump toothed wheel have differently positioned keyways for the woodruff key? (now there's an anoraks question!!) As I have the JX wheel fitted currently?!

I'll check the part numbers with VAG tomorrow, but any help/suggestions welcomed.

Thanks, Andy

Post by **andysimpson** » 15 Sep 2008, 20:32

mahatmacoat wrote:I realise that AAZ internals in the JX pump will be okay, I'm having problems timing the pump.

Does anyone know if the AAZ and the JX pump toothed wheel have differently positioned keyways for the woodruff key? (now there's an anoraks question!!) As I have the JX wheel fitted currently?!

I'll check the part numbers with VAG tomorrow, but any help/suggestions welcomed.

Thanks, Andy

Keyway postions the same, i have had this problem twice after fitting a dry pump, i think the adavance mechanism gets air locked, that why i recommended gravity feeding pump, especially if you have one of the stupid fuel filter setups.

Post by **mahatmacoat** » 15 Sep 2008, 20:43

Aha, I see!

Okay, how are you gravity feeding the pump as I've installed a bulb on the inlet & clear fuel lines in & out, so can see any air. I've also had the pump tipped to it's extremes both ways, so would hope that might dislodge any trapped air?!

What does a 'stupid filter' setup look like. I have the standard line in line out with plug in return filter tied to the bulkhead at the right rear of the engine bay. Is there an improved filter/location?

Post by **andysimpson** » 15 Sep 2008, 20:53

mahatmacoat wrote:Aha, I see!

Okay, how are you gravity feeding the pump as I've installed a bulb on the inlet & clear fuel lines in & out, so can see any air. I've also had the pump tipped to it's extremes both ways, so would hope that might dislodge any trapped air?!

What does a 'stupid filter' setup look like. I have the standard line in line out with plug in return filter tied to the bulkhead at the right rear of the engine bay. Is there an improved filter/location?

If you have the filter with 2 hoses its good, if you have the 4 hose type they are "pooh".

Diesel coming out of a bottle higher than pump.

Does it still have JX cold start advance mechanism, is the lever defo in the off position, if you push all the way back it advances it again, its on a cam.

Post by **mahatmacoat** » 15 Sep 2008, 21:02

It has the 4 hose filter, but sounds like next time it needs changing it'll get an upgrade.

Yes, it still has the JX coldstart mechanism (the wire push pull with a pinch bolt holding the wire & a backing plate to control the start/stop point).

When viewed from the side of the pump, the lever sits at approx 3 oclock unadvanced & approx 11 oclock when advanced. Is that about right? If not, how can I tell where to locate/re-index it?

Post by **andysimpson** » 15 Sep 2008, 21:06

mahatmacoat wrote:It has the 4 hose filter, but sounds like next time it needs changing it'll get an upgrade.

Yes, it still has the JX coldstart mechanism (the wire push pull with a pinch bolt holding the wire & a backing plate to control the start/stop point).

When viewed from the side of the pump, the lever sits at approx 3 oclock unadvanced & approx 11 oclock when advanced. Is that about right? If not, how can I tell where to locate/re-index it?

It should have a bit of freeplay when lever is in off postion, if you move in backwards and forwards you will feal when the cam takes effect.

The 4 hose filter is terrible for holding air, especially on short journeys.

Post by **mahatmacoat** » 15 Sep 2008, 21:10

Andy, thanks for the help & advice. Will check for air & check the advance lever!

I'm intrigued to know more about your V10 Doka project, I'm sure the wiring & piping are a joy!!