B4 80, octane plug?

Blackie · 07-09-10, 08:02 AM

How do?

Coming from an extensive Vauxhall back ground, I am aware that the old mk3 cavs and astras had an octane plug in the engine bay near the bulhead, so that you could easily use different octane fuel by unplugging and turing around the little plug.

I am wondering is there such a thing on the Audi 80 b4 models? if so where?

The reason I ask is that my 1.6i ADA engined 80 runs better on super than on regular, having a little flatspot, if not more like a hesitation at between 2-3000rpm on regular, nothing there on super.

Can anyone help?

Ben · 07-09-10, 05:50 PM

The manual says the 1.6 + 2.0 8v uses not lower than 91 RON, the engine management takes care of ignition timing if you put in a higher octane petrol so you don't have an octane plug to swap around.

Blackie · 07-09-10, 08:16 PM

So why would my car be hesitating on normal grade fuel and not on super? Normal iirc is 94ron and Super is 97-99ron?

Blackie · 11-09-10, 08:40 AM

anyone help?

Micky · 11-09-10, 08:53 AM

It’s probably because the unleaded is really old 3 star petrol and cars just about run on it.
If you had an old carb car it would pink and run shite. That’s why you can only run 97ron.
Newer cars with ecu aromatically reduce the timing for 95 and advances for 97. This is why your car has a flat spot. Just use 97 all the time: tup: some cars don’t advance so you can run on 95 and 97 don’t make any difference at all.

msh · 11-09-10, 05:38 PM

Turn ignition a bit later. Maybe detonation sender is gone, who knows. After 3A was installed in my former A80, I had some problems with detonation and something like that "flatspot" thing, only in lower rev range, so I slowly learned how to properly adjust ignition for that engine and after new detonation sender was installed [old one was with cracked plastic shell and wire wasn't in better condition] and ignition properly adjusted [by feel] there was no problems with ignition thereafter.

Blackie · 11-09-10, 05:58 PM

So where is the detonation sensor located on the 1.6i Ada engine?

msh · 11-09-10, 06:20 PM

Must be in the same place where it is on other VAG 4 pot engines - on left side [passenger side in UK and ROI] of engine block. Do I have to say that it looks like this one?

Blackie · 11-09-10, 06:52 PM

Cheers lad, it's pissing down outside ATM so will have a look tomorrow

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07-09-10, 05:50 PM	#2
Ben 4 ring whore! Classic Audi Club Member Join Date: Mar 2008 Location: Stockport Posts: 2,348	The manual says the 1.6 + 2.0 8v uses not lower than 91 RON, the engine management takes care of ignition timing if you put in a higher octane petrol so you don't have an octane plug to swap around.

07-09-10, 08:16 PM	#3
Blackie Grown up member Join Date: Sep 2010 Posts: 60	So why would my car be hesitating on normal grade fuel and not on super? Normal iirc is 94ron and Super is 97-99ron?

11-09-10, 08:40 AM	#4
Blackie Grown up member Join Date: Sep 2010 Posts: 60	anyone help?

11-09-10, 08:53 AM	#5
Micky Mr Fifty Thousand! Classic Audi Club Member Join Date: Apr 2008 Location: Birmingham Posts: 8,738	It’s probably because the unleaded is really old 3 star petrol and cars just about run on it. If you had an old carb car it would pink and run shite. That’s why you can only run 97ron. Newer cars with ecu aromatically reduce the timing for 95 and advances for 97. This is why your car has a flat spot. Just use 97 all the time: tup: some cars don’t advance so you can run on 95 and 97 don’t make any difference at all.

11-09-10, 05:38 PM	#6
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	Turn ignition a bit later. Maybe detonation sender is gone, who knows. After 3A was installed in my former A80, I had some problems with detonation and something like that "flatspot" thing, only in lower rev range, so I slowly learned how to properly adjust ignition for that engine and after new detonation sender was installed [old one was with cracked plastic shell and wire wasn't in better condition] and ignition properly adjusted [by feel] there was no problems with ignition thereafter.

11-09-10, 05:58 PM	#7
Blackie Grown up member Join Date: Sep 2010 Posts: 60	So where is the detonation sensor located on the 1.6i Ada engine?

11-09-10, 06:20 PM	#8
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	Must be in the same place where it is on other VAG 4 pot engines - on left side [passenger side in UK and ROI] of engine block. Do I have to say that it looks like this one?

11-09-10, 06:52 PM	#9
Blackie Grown up member Join Date: Sep 2010 Posts: 60	Cheers lad, it's pissing down outside ATM so will have a look tomorrow