JX to Seat AAZ conversion - Throttle linkage problem

[vantheman]

Conversion completed with MOT and on the road. Project fairly straightforward apart from reindexing of AAZ Turbo which I was forced to use because JX turbo clapped.

Note to others using AAZ turbo the two halves are interference fit and you
need lots of heat.

Performance at present is not as good as original JX, due to throttle linkage problem.

On the JX pump there is probably only 60 degrees of throttle movement while on the new pump there is say 90 degrees.
The problem is that the standard diesel throttle cable has only limited
travel and will only open the new pump half way.

I have moved the cable pickup point nearer the pump spindle in order to get more travel but have reached a point where the pressure required on the throttle pedal is likely to break the cable.

Anybody out there had this problem and is there a simple fix?


Incidently on the AAZ pump there is a two stage system, using two heavy coil springs, in which the second stage only comes in at maximum opening. There is also a damper which further stiffens the throttle operation. Can any of this be descarded?

Any advice appreciated

[Diamond Hell]

Odd problem with an AAZ - let's have a pic of your pump, please.

If this is insurmountable at the pump end you could cut the linkage arm below the throttle pedal and weld more steel in to create a longer arm with more leverage. I've done this on an Audi conversion - worked fine. If you need a pic I can do that as it's sitting on a bench at the moment.

[vantheman]

Thanks for the reply Diamond

Have considered increasing length of throttle pedal lever but put it
off because of difficulty in accessing .

Will have to wait to post a pic until the daughter returns from Uni.

Vantheman

[Simon Baxter]

It's no two stage throttle thing.
It just gives the impression that the throttle pedal is going down but the throtle spindle on the pump doesn't turn any further.
Swap the bracketry from your old pump.

[HarryMann]

Wasn't aware of this, would be good to swap pictures of pumps, see what we've both got, pretty sure mine is AAZ and opens fully, Simon's seen it and didn't comment on that - other tha Ugh! What a frellin mess... and there were more pressing issues at the time

Re-indexing is in Wiki now, didn't need heat, just plenty of gentle tap, tap from hammer in right spot to free exhaust section, but 'tis a bugler for sure.!

So, have you also re-indexed your dipstick

[vantheman]

Thanks Simon And HarryMann for the replies.

I had suspected that this second stage throttle opening was purely
cosmetic but not having dealt with diesels before was not confident of
scrapping the Seat system. Following your advice have now removed all the junk including the damper , fabricated a new cable support and problem solved.


Wish the turbo reindexing Wiki had been up when I did mine, took it to
the local blacksmith shop (he,s a mate) set it in the big vice and gave it some wellie , no chance, only when we put some heat on the hot section
did it turn, we could find no way of actually splitting the two halves and it locked solid once cooled. I decided to turn it 180 degrees while hot and
reassembled as per the wiki. Nb when drilling and tapping the repositioned wastegate bracket I managed to break through into the
aluminium plenum chamber which I hope to have sealed by locking the bolt with stud sealer. There is very little metal to play with and drilling needs to be extremely accurate .

Dip stick modified as per the book.

Thanks lads

vantheman

[HarryMann]

There is very little metal to play with and drilling needs to be extremely accurate .

Years of practice ... amazing what you can do with a B&D! Always centre-pop and always go in with a sharp 1/8" to start with, and wrap masking tape around the drill shank at the required depth. Once you've piloted, take drill out chuck and stand it up in the job - eyeball from both directions - correct angle at next size up - don't correct angle when using tapping drill-size. A good vacuum cleaner is handy to have close-by with blind holes and threads too...

I'm sure yours'll be fine if you used threadloc!

There's now information up there about setting and testing the wastegate solenoid operation, just need a footpump with a built-in gauge.

PS. Those lightweight slow-speed screw winders are good for drilling small holes in soft materials like ally and monkey metal - better control than heavy battery drills. Got a gem from B&Q a few years back, gorgeous bearings and auto-chuck and haven't managed to kill it yet (re-badged German origin) - trick is, don't lend your good drill out, friends can wreak destruction in one weekend

[vantheman]

HarryMann,

Can't find there info on wastegate testing .Where's this held?

[HarryMann]

http://www.club80-90.co.uk/wiki/index.p ... ndexing%29

Go down and look for subtitle 'Wastegate mechanism testing'