Need help with Golf mk3 TDI

K

Kaktuss

New member
Joined
Jun 12, 2018
Location
Kandava, Latvia
TDI
Golf mk3 AHU (1Z spare engine)
Hi everyone. I have few questions related to Golf mk3 1.9 TDI (1Z and AHU engine codes).
1. What is the real diffrence (except ECU and imob) between 1Z and AHU engine?
2. Anyone knows the plunger travel for one of these engines or do I really need to connect with computer to check the ignition timing as said by Autodata and Haynes manual?
3. A mate has AHU engine, in idle it revs at 1200 rpm's and when you drive, has almost a total power loss at 2400 rpm's (just doesn't pull the car forward like it should). Any idea what is the problem? One thing is for sure, the previous owner did change the fuel pump. Could it be ignition timing, or the electrical part of the fuel pump? Or could it be the gas pedal with potentiometer?
I would be very grateful with answers for 2 and 3 question, cause those are the most time sensitive at the moment. Thank you all in advance.
 
Last edited:
J

Jzallan

Well-known member
Joined
Jul 28, 2012
Location
Cambridge mn
TDI
2001 jetta TDI, 2002 jetta TDI, 1996 Passat TDI, 2004 Passat TDI
Kaktuss said:
Hi everyone. I have few questions related to Golf mk3 1.9 TDI (1Z and AHU engine codes).
1. What is the real diffrence (except ECU and imob) between 1Z and AHU engine?
2. Anyone knows the plunger travel for one of these engines or do I really need to connect with computer to check the ignition timing as said by Autodata and Haynes manual?
3. A mate has AHU engine, in idle it revs at 1200 rpm's and when you drive, has almost a total power loss at 2400 rpm's (just doesn't pull the car forward like it should). Any idea what is the problem? One thing is for sure, the previous owner did change the fuel pump. Could it be ignition timing, or the electrical part of the fuel pump? Or could it be the gas pedal with potentiometer?
I would be very grateful with answers for 2 and 3 question, cause those are the most time sensitive at the moment. Thank you all in advance.
Click to expand...
I had one where the mass flow air sensor went bad. Idled fine, but no power.

Sent from my SM-T377T using Tapatalk
 
Steve Addy

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
No real big difference between the two but internally perhaps a few things. I think connecting rods were originally different but little else. Valves were originally 8mm then at some point changed to 7mm, but I'm not sure that's specific difference between 1Z and AHU.

At idle AHU should idle at 975 rpm. Power loss could be number of things but often it's due to faulty vacuum or pressure hose from ECU to manifold and also N75 switch over valve. If the vacuum routing has been improperly installed for N75 and N18 then that can cause limp mode. Check the connection at the turbo too, if that line comes detached it will cause limp mode.

It's really easy to set the injection pump timing if you have cable and software. I'm not sure that plunger travel numbers were published for this to be set with a lift gauge.

Hope this helps!

Steve
 
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