AAZ that has sat for a long time

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
I'm trying to revive an AAZ that has 50,000k on it but has sat for 5 years. It turns over and was not seized but just spins with no kick. So I need advice on what to check and what to try to get this thing firing again.

What I have checked.

There is power to the solenoid at the injection pump.
There is power to the glow plug rail but glow plugs maybe toast.
The fuel is old and could be a problem. I might try fresh fuel from a can.
Not sure what type of spray to use to get it to fire. Ether? I have heard WD40 will work?

I will pull the injectors to check and do a compression check. I will pull the glow plugs and test them. I'm not sure if the old diesel fuel would have turned to sludge and clogged the injection pump.

Any help would be appreciated. Thanks
 
Last edited:

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4, '97 Jetta
You’re trying to burn 5yo fuel? I have a feeling the vanes in the pump are seized. Were you getting smoke at the tailpipe?

-Todd
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2005 BEW Wagon
Some suggestions:

1) DON'T use starter fluid... it's very hard on engines with glow plugs, and really doesn't tell you much anyways other than that you may have a little compression left.:)

2) DO make sure your glow plugs are working... the AAZ is an IDI engine and needs 'em to start, even in the summer.

3) DO drain and then refill the IP with fresh fuel and make sure it's primed by loosening the nut at the top of each injector a bit and then crank (have a rag, fire extinquisher handy etc etc). You'll need to get the internal vane pump working, and making sure it's full of fresh fuel plus providing a way for the air to get out will help save your battery and starter.

4) DO make sure you've a strong battery... IDI engines need to turn over fast to generate heat. I sometimes will jumper to a running car just to make sure I don't run out of electrons.

5) DO give your starter breaks while cranking so that it cools off. 20 seconds of cranking followed by a couple minutes of cooling will save you from needing a new starter soon. :)

Working glow plugs and a primed IP and she should run... AAZs are tough to kill. :)
 
Last edited:

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
Tank is like 3/4 full. lol I will have to find a way to get rid of the diesel.
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2005 BEW Wagon
If you can rig up a temporary jerry can to run into the pump it's a great way to go... you know you will be using fresh diesel *and* it will be much easier to get the IP to prime with gravity helping.

Speaking of fuel, replacing the fuel filter is probably a must-have too... it will not have aged well and could well be clogged with algae at this point.

Fingers crossed for you!!
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I'd agree with the other comments about a 5 yo idle engine probably not having a good IP. There tends to be some residual gunk in there that causes problems. You can kind of check that by removing the exposed side cover on the IP down at the timing advance device to see if it's rusty down there.

If you do try and start it I would definitely replace the fuel filter and use a vacuum pump to pull clean new fuel through the IP. I know others talk about algae but I have never seen an algae contamination in all my years with diesel. I think perhaps in areas of the country where there's no freeze cycle for winter it might happen but even in Iowa having had diesel for much of my adult life I've not seen it.

Good luck

Steve
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
I will give all the suggestions a try tomorrow and report back. I will for sure short cut the fuel line to a fresh can of diesel and loosen the nuts on the fuel lines at the injectors. Will also check glow plug function. Thanks everyone.
 
Last edited:

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
OK I short cut the supply of diesel to a Jerry can and bled the injection lines at the injectors which were dry and the puppy fired up. It took 30 mins of playing the 20 second games and waiting 10 mins for the starter to cool down but she runs very well. Seems to idle a touch high for me but a steady idle at 1100rpms.
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2005 BEW Wagon
Excellent!!!!

If you don't mind one more suggestion: the very first thing you might want to do is to carefully watch the harmonic damper (big pulley attached to the crank)... from underneath the car... while the engine is running. You're looking for side-to-side wobble.

I mention this because if you see any significant wobble it will strongly suggest that the engine has fallen prey to the single most common AAZ issue: a worn crank snout.

When the crank snout wears the pulley wobbles but also the crank/cam timing starts to wander as the engine pounds away on the snout, and before long pistons meet valves with a bang.

To fix the engine needs to come out and good AAZ cranks are getting hard to come by... good issue to eliminate before you spend any further time or money? :) :)
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4, '97 Jetta
Great news!

If the crank nose is worn, why not have the crank modded to run the TDI sprocket? I can’t see cutting the flat, too much of a challenge for a competent machine shop.

-Todd
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
I will check for wobble. But if there is NO wobble is there anything that can be done to keep it that way?

Should I add some type of injector cleaner to my jerry can to do a direct clean?

Is there anyway to save the 10 year old diesel in the tank?
 
Last edited:

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
As above, the snout on the AAZ cranks is a weak design.

Best option is to remove the crank and machine it to the D-shaped later style and use a ALH/AHU crank pulley.

Failing that, it would be wise to check and replace the crank pulley you have now, using a new crank bolt torqued to spec.

Also, install a later style one-way alternator pulley to relieve the inertial forces on the crank pulley from the alternator rotor.
 

0die

Veteran Member
Joined
Nov 29, 2012
Location
corpus christi, tx
TDI
1996 Passat wagon B4V
I wouldn't both draining the tank just yet...see if it will run off the tank, the old diesel might still be fine...just burn thru that tank with some algaecide or other diesel additive/cleaner....all the way thru til it starves of fuel so it's almost all flushed out...then add a tank of fresh fuel to rinse the tank and then a new filter...

I picked up an old abandoned Mercedes that had been sitting at the navy impound lot for several years...all it took was a new battery and several starter cycles (with cool downs) to prime the pump and it fired up and ran smooth....
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
Just a long shot but does anyone have a pic of the vacuum line schematic for a 1993 AAZ Passat?? Seems most of the lines from the breather box out have been removed or fallen off. lol
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
As above, the snout on the AAZ cranks is a weak design.

Best option is to remove the crank and machine it to the D-shaped later style and use a ALH/AHU crank pulley.

Failing that, it would be wise to check and replace the crank pulley you have now, using a new crank bolt torqued to spec.

Also, install a later style one-way alternator pulley to relieve the inertial forces on the crank pulley from the alternator rotor.

What did the alternators come on? I have never heard of a one-way alt.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4, '97 Jetta
When I inspected the snout on my AAZ, it was perfect. The sprocket was also, so I just reinstalled everything with a new bolt.

I’m using all the A1 accessories on this engine, so I’m guessing the v-belts give everything some slip, that’s needed.

The crank can always be cut later, if needed.

-Todd
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
So my alt is toast anyway. Had sat for 10 years and was seized so I cranked the crap out of it by hand and broke it free. So if I was going to replace the alt with another direct fit could I put a later ALH alt on it with no mods or what is the best alt with no mods. Thanks
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2005 BEW Wagon
Your alternator is specific to the AAZ in part because it has specific wiring to drive the tach.

In terms of an upgrade, an over-run pulley can be easily retro-fitted to an OEM AAZ alternator.
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
Ok one last question. I have an ALH diesel pulley now but it looks like at some point the alt voltage reg toasted and took out the Alt wiring.

Does anyone have a rear shot of the alt or a wiring diagram. My kid has my Bentley for the Passat.

I believe at the Alt there is a red/black wire and blue in a female plug which are no longer there. Red/black(D+) - idiot light on dash and blue(W) - tach also if I remember correctly. And big red(B+) power wire. Previous Owner made some new thing I think.
 
Last edited:

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
On a separate note could I not just use the ALH Alt??? Just take the alt wiring from an ALH and apply it to the AAZ?? Plugs will be different but I can splice them together.
 
Last edited:

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2005 BEW Wagon
As posted, you'd need to add the extra internal wiring to run the tach (and oil pressure warning system)... it's not a bolt-on.

Not hard to do, but would need to be done. The tach terminal wiring (W terminal) is just a wire to one of the diodes on the other side of the output.

Are you sure it will fit mechanically... from a mount but also shaft offset perspective?
 

1975 Kombi

Veteran Member
Joined
Jun 3, 2014
Location
Acton, Ontario, Canada
TDI
2003 TDI Jetta, 2011 Touareg TDI, 1992 D Jetta, 1992 TD Jetta, 2001 NB TDI, 1992 Golf coupe D
What's the torque on the new clutch pulley? I've bought the tool and have a functioning clutch pulley but need the torque spec. Thanks

Found it 59ft/lbs
 
Last edited:
Top