Favorit Pinking

[DaveCZ/UK]

Guys just one more minor thing. My 1988 Fav has always had pinking under a low load. I read in my Haynes book, a little tip, and wondered if it would really cure the problem. It said to remove the vacum nut from the dissy, and add another washer 2.5 to 3.0mm. Will this stop my annoying pinking?

[KenONeill]

This is one of 2 things, one serious and the other more of a driver issue:-

1) Driver issue. The car's fine, but you're asking it to pick up from too low an engine speed.
2) Serious issue. The car actually is pinking at low revs. Unfortunately, this doesn't usually stop as the engine speed increases. It just gets higher in frequency (both pitch of note and occurancies per minute) and becomes inaudible. This can lead to overheating, and/or burnt valves. The cure is to either run slightly higher octane fuel, or slightly more ignition advance, which I imagine is what Haynes are up to. It would be nice if they explained it properly!

[DaveCZ/UK]

So Ken? Can I carry out the mod to the vacum nut? I can confirm it's not my driving. I use leaded petrol. And yes it's still widely on sale here. This is the recommened fuel from the factory for this age car. I understand I cant put unleaded in? The leaded fuel is 91 ron and the unleaded is 95 ron, you thoughts please

[KenONeill]

91RON sounds way too low an octane to me, and I'm dubious about that being leaded too; Old UK 2* wasn't leaded and was 93RON.

I think you'd need an additive to run unleaded, but I'm not certain.

It does confirm my opinion that you've got a real pre-ignition problem. I'm not sure how much timing control you have on a Favorit without the sort of trick Haynes describe though.

[richardsfavorit]

I had an M-reg Favorit for years, and Dad had it from new and it always pinked! A lot of the Favorit's Dad had always did. I spoke to my garage about it, and they said it was ok, a lot of Favorit's do this.

[lewist123]

my fav never pinked!

is the ignition too advance?

is it running too lean?

stick some super in and see what happens?

pinking is usually a really really bad thing!

[rigsby]

Originally Posted by KenONeill

This is one of 2 things, one serious and the other more of a driver issue:-

1) Driver issue. The car's fine, but you're asking it to pick up from too low an engine speed.
2) Serious issue. The car actually is pinking at low revs. Unfortunately, this doesn't usually stop as the engine speed increases. It just gets higher in frequency (both pitch of note and occurancies per minute) and becomes inaudible. This can lead to overheating, and/or burnt valves. The cure is to either run slightly higher octane fuel, or slightly more ignition advance, which I imagine is what Haynes are up to. It would be nice if they explained it properly!

Dont advance the ignition, that is the problem (pinking is pre ignition). Try retarding it a couple of degrees

[KenONeill]

Originally Posted by rigsby

Dont advance the ignition, that is the problem (pinking is pre ignition). Try retarding it a couple of degrees

Huh!!!? More advance = firing further before TDC, hence stopping the pre-ignition occuring by setting off the controlled burn from the plug before the uncontrolled one from the hot spot gets a chance.

Which gives me another idea. Has anyone ever tried to cure this by decoking the engine?

[lewist123]

Ken - no! more advance means it fires closer to TDC... you got it the wrong way round! if you want to reduce pinking, retard the timing!

[richardsfavorit]

The trouble is on the later Favorits I didn't think you could change the timing - definitley wasn't an option on our M reg one.

[rigsby]

Originally Posted by richardsfavorit

The trouble is on the later Favorits I didn't think you could change the timing - definitley wasn't an option on our M reg one.

You can play with the ignition timing on all favorits, and all spi felicias, as they have an adjustable distributor

just to clear things up, Pinking is pre ignition
To advance the timing, is to make the spark fire earlier, as the piston goes up on the compression stroke
To retard te timing, is to make the spark fire later (nearer TDC)
Pinking occurs when the spark fires too early and the combustion gasses try to force the piston back down the bore (in theory the wrong way) The fact that the piston is still going UP and trying to compress the expanding gasses makes the PINKING SOUND
There it is all clear. Feel free to give me loads of thanks

[richardsfavorit]

You have cleared up my perception of it - thanks!