PD 130 manual 32mpg :(

[S66MJETDI]

I'm led to understand 0-0 - 0.5 is ideal.....

[Google44]

I have seen that too. It claims that 0.5 to 1.0 is best. If someone can confirm that value I've listed is timing I should be able to try to turn in unticlockwise a bit.

[S66MJETDI]

This I need to sort out.......

[ajrayner]

Removing the cat removes restriction in flow - therefore reduces back pressure ?

Yep, you're right but it still increases stress on turbo shaft apparently by spinning up too quick

[S66MJETDI]

Yep, you're right but it still increases stress on turbo shaft apparently by spinning up too quick

Seems like a damn fine excuse for a more beefy turbo...... once my niggles are sorted out the old girl will be receiving a mild remap .... So it wont hurt.... I hear there are a few of the 170bhp rated 2.0tdi's that bolt straight on, I assume these may be a little stronger, can anyone confirm?

[ajrayner]

Google44

Monitoring synchro angle at idle is sufficient...ideally 0 but you can always monitor the fuel consumption (also in engine measuring blocks in VCDS) at idle with any adjustments you make to find your "sweet spot".

A mass of numbers from a log is difficult for anyone to read. Check out this site for tips on how to turn the data into more useful graphs and also excellent gen regards engine health checking using VCDS. It's a passat website but it's the same 1.9 PD engine in our Audis

[S66MJETDI]

Just to add to my suspicion that my mpg issue was poor timing . Over the last few days I have ratcheted up 47 miles since reseting the timing..... every time I get in the car now it seems smother and more powerful like the ecu is readjusting something or something is clearing...... Is there a rational explanation for this - would the ecu be relearning or is it not that bright on this age of car?

[ajrayner]

In a nutshell, if the timing is out then fuel is injected into the cylinder at a point where the piston is not in the optimum position to generate maximum driving force on the crankshaft for that given squirt of fuel. The result of this is a reduction in torque (moving force) for the fuel squirt amount. The ecu can compensate for this mismatch to a certain degree by delaying/advancing the fuel squirt. It can only do so much though and is no substitute for mechanical harmony between cam and crank ie fuel squirt happens when piston is at maximum extension. This leaves to ecu to concentrate on providing the drivers wish map effectively ie throttle pedal position.

Not an experts explanation but hopefully it makes some sense!? If you really want the juicy details the checkout this bedtime reading.

[S66MJETDI]

Lol I'm familiar with the static burn rates of fuel at different temps and the constant need to adjust injection timing to compensate for the dynamic changes in the speed of the piston stroke...... just wondered if the ECU's in our cars were advanced enough to relearn optimum settings in relation to static engine settings. ( I spent many years repairing jet aircraft engines...... slightly different in operation but many of the principles still hold.)

[S66MJETDI]

P.s thanks for the doc though theres always learning to be had....... Shall give it the once over tonight.