Hey,

This used to be an article on the old website ages ago, and I printed it off and kept a copy of it. I can't find it anywhere else so thought I'd bung it back on here for people to use. Hopefully it'll get made into an FAQ. These aren't my own words by the way, so credit should go to whoever wrote it in the first place! I can however testify that the methods described work :)

Service Adjustment Mode

Before attempting to set the ignition timing or base idle speed, the ECU must be put into 'service adjustment mode'. This is done by making sure the engine is thoroughly warm and then disconnecting the multiplug from the blue coolant temperature sensor while the engine is running. If all is well with the management system the engine RPM should increase slightly when the plug is disconnected.

If the engine stalls at any point while making adjustments to the timing or base idle speed the multiplug MUST be refitted to the blue coolant temperature sensor before attempting to re-start the engine. Failure to do this will cause the ECU to enter 'limp home mode'. Adjustments will then not be possible until you have cleared the fault/s from the ECU memory.

Ignition Timing

The procedure described in the Haynes manual will give a rough timing setting. To set the timing accurately the following procedure must be followed. Digifant has an unusual procedure for setting the timing so please follow the instructions carefully.

With the ECU in service adjustment mode blip the throttle so that the engine RPM exceeds 2500. Do this four times.

Increase the engine speed from idle to between 2000 and 2500 RPM and check the timing. It should be 6º ± 1º. If adjustment is needed, slacken the distributor fixing bolts and turn the distributor until you have the correct timing.

Allow the engine to return to idle speed and reconnect the multiplug to the blue coolant temperature sensor. Blip the throttle three times, making sure the engine speed exceeds 3000 RPM each time.

Check the ignition timing now advances with increased RPM by slowly increasing the engine speed while watching the timing marks. Without an expensive timing light you will not be able to accurately measure the advance, but it should be around 40º at 2800rpm.

Idle Speed

Before attempting to adjust the idle speed make sure the ignition timing is correct. It is also worth taking the ISV (idle stabilisation valve) off the engine and thoroughly spraying it with carburettor cleaner. The valve is located beneath the inlet manifold, bolted to the steel water pipe.

The regulated engine speed is controlled by the ECU and is not adjustable. The ECU regulates the idle speed by opening and closing the ISV and also by making continuous small adjustments to the ignition timing. However for this to work properly the base idle speed must be set correctly.

To set the base idle speed, remove the breather hose from the cam cover, and plug the hose. Start the engine and allow it to idle for a couple of minutes, then put the ECU into service adjustment mode.

Blip the throttle three times, ensuring the RPM exceeds 3000 each time. Allow the engine to return to idle and then use the idle adjustment screw on the throttle body to set the idle speed to 920 RPM ± 25 RPM.

Re-connect the coolant temperature sensor multiplug, then unplug and reconnect the breather hose. The engine speed should now settle down to the correct regulated figure of 900 - 950 RPM.

Speaking from experience - doing this can help determine faults with other sensors or components of the engine management system. Hopefully this will help those of you with poor running GT's get them sorted!

Thats helpful.

Whats the crack with blipping the throttle though? Iv never done that before...

Thats helpful.

Whats the crack with blipping the throttle though? Iv never done that before...

I was told that is to clear any BTS reading the ECU may have stored.

All the Autodata/Vag Manuals I have ever seen say to set timing to 5deg +/- 1. Nothing major but just a warning

is the idle speed to be set when the engine is at its operating temp or cold?

The engine should be at full operating temperature - preferably with the fan off.

Cheers for posting this. I scrounged a timing light from Freecycle so I'll check my GT over at some point. One question though: mine idles at about 700rpm. Is this bad? It's got a Poloace chip on, if that makes any difference.

Absolute diamond mate!!!

I've just had a new dizzy fitted, and i went to a garage to have the timing set, but they couldnt do it properly. And through reading this, i realise why!!!!!

So I've got my mate cummin round 2morra with his timing light to sort it properly.

Thanks again Minis84, this has been a great help.

Cheers for posting this. I scrounged a timing light from Freecycle so I'll check my GT over at some point. One question though: mine idles at about 700rpm. Is this bad? It's got a Poloace chip on, if that makes any difference.

Either your timing or idle needs adjusting or you have a SPi dizzy mate.

oright m8 i am just wonderin about my standard 1.3 cl coupe I'm doing a GT conversion and iam just wonderin about the wireing loom or any other problems

does this work on a 1997 reg 1.0 polo 6n or is it possible if you could get hold of one, please?

Hey,

This used to be an article on the old website ages ago, and I printed it off and kept a copy of it. I can't find it anywhere else so thought I'd bung it back on here for people to use. Hopefully it'll get made into an FAQ. These aren't my own words by the way, so credit should go to whoever wrote it in the first place! I can however testify that the methods described work :)

Service Adjustment Mode

Before attempting to set the ignition timing or base idle speed, the ECU must be put into 'service adjustment mode'. This is done by making sure the engine is thoroughly warm and then disconnecting the multiplug from the blue coolant temperature sensor while the engine is running. If all is well with the management system the engine RPM should increase slightly when the plug is disconnected.

If the engine stalls at any point while making adjustments to the timing or base idle speed the multiplug MUST be refitted to the blue coolant temperature sensor before attempting to re-start the engine. Failure to do this will cause the ECU to enter 'limp home mode'. Adjustments will then not be possible until you have cleared the fault/s from the ECU memory.

Ignition Timing

The procedure described in the Haynes manual will give a rough timing setting. To set the timing accurately the following procedure must be followed. Digifant has an unusual procedure for setting the timing so please follow the instructions carefully.

With the ECU in service adjustment mode blip the throttle so that the engine RPM exceeds 2500. Do this four times.

Increase the engine speed from idle to between 2000 and 2500 RPM and check the timing. It should be 6º ± 1º. If adjustment is needed, slacken the distributor fixing bolts and turn the distributor until you have the correct timing.

Allow the engine to return to idle speed and reconnect the multiplug to the blue coolant temperature sensor. Blip the throttle three times, making sure the engine speed exceeds 3000 RPM each time.

Check the ignition timing now advances with increased RPM by slowly increasing the engine speed while watching the timing marks. Without an expensive timing light you will not be able to accurately measure the advance, but it should be around 40º at 2800rpm.

Idle Speed

Before attempting to adjust the idle speed make sure the ignition timing is correct. It is also worth taking the ISV (idle stabilisation valve) off the engine and thoroughly spraying it with carburettor cleaner. The valve is located beneath the inlet manifold, bolted to the steel water pipe.

The regulated engine speed is controlled by the ECU and is not adjustable. The ECU regulates the idle speed by opening and closing the ISV and also by making continuous small adjustments to the ignition timing. However for this to work properly the base idle speed must be set correctly.

To set the base idle speed, remove the breather hose from the cam cover, and plug the hose. Start the engine and allow it to idle for a couple of minutes, then put the ECU into service adjustment mode.

Blip the throttle three times, ensuring the RPM exceeds 3000 each time. Allow the engine to return to idle and then use the idle adjustment screw on the throttle body to set the idle speed to 920 RPM ± 25 RPM.

Re-connect the coolant temperature sensor multiplug, then unplug and reconnect the breather hose. The engine speed should now settle down to the correct regulated figure of 900 - 950 RPM.

Speaking from experience - doing this can help determine faults with other sensors or components of the engine management system. Hopefully this will help those of you with poor running GT's get them sorted!

No, it won't, this is for Digifant , your engine likely runs on Motronic MP 9 injection system or SP, I'd like to find such an easy way to check and set the ingnition timing on my 6n AEX 1.4l ,44kw tough.

Too bad this system still has the distributor "setable" .

Useful bit of info, thank you.

A couple of stupid q's about the below paragraph. When you say 200-2500rpm do you mean hold the throttle at that or adjust the idle screw?

When you say 6+1, what do you mean? Sorry to be so simple but I have timing light and really want to get this right!

Cheers

Increase the engine speed from idle to between 2000 and 2500 RPM and check the timing. It should be 6º ± 1º. If adjustment is needed, slacken the distributor fixing bolts and turn the distributor until you have the correct timing.

Edited 6 June, 201214 yr by Tomgti

it should be 6 degrees, but theres a tolerance of 1 either way, so either 4 or 7 should work fine, just see whts best i suppose

i've been told that my problem is ignition timing but it says on here that the engine should be warm, thing is when my engine gets warm it dies! anyone got any suggestion on how i can resolve my problem?

Great Guide. Going to do this tomorrow.

Btw, Since coolant temperature sensor being unplugged from wires - is there chance to overheat engine or blow up a radiator because of that?

How do I know what timing degree is of distributor? Do I need diagnostic OBD2 tool for my Polo? Because I bought from ebay one and its working good on Golf4 but its not working on my Polo, not connecting to ECU :/ And this is for diesel engine or just petrol?

Edited 8 June, 201313 yr by scorpio1991

its wrong about the idle valve , these dont work like described on a polo

 

its just a valve thats open when cold that boosts the idle , as the 12v heater warms it , it will close and stay like that , heat from the water pipe keeps it warm for warm starts 

 

it has no ability to open and close on demand at all

I'm running 8deg advance, dialled in using service adjustment mode. The engine spins up a lot faster when you gas it out of gear at this setting. Conversely, it is very economical on motorways set at 4deg, uses very little fuel