5L Pinking at full throttle

[bennem]

I've had a look through the archives and it seems that pinking with a 5L is just what happens. But I just want to be sure that I'm not killing the engine.

Before the folks with shares in Shell start I am using Optimax and have been doing so for the last 1000miles or so.

If I progressively open the throttle I have no pinking until about 4k but cannot give it full throttle without pinking.

If I am about 3k and floor it...... lots of pinking.

Soooo, is this the norm with the 5L with no mods? If so how do you stop the pinking, get a new ECU?

BTW having recently moved up towards Bicester I have seen a ship load of TVR's. Where I work there is a red Chim just around the corner, a green Griffith who passed me the other day (only just started the car so couldn't give chase) and I also see a red Chim frequently on the A34 amazing.

[JonRB]

I have a sort of stuttering lumpy misfire type thing about 5k revs on my Chimaera 500. Is that what you're referring to?

[DustyC]

All I have ever noticed is an occasional flat spot around 4K.
Its not consistant though and quite rare so I have started to think Im imagining it!

I guess a lot of the TVRs you see could be on their way to/from SilvertoneTVR.

[tahiti450]

[quote=bennem]
If I progressively open the throttle I have no pinking until about 4k but cannot give it full throttle without pinking.

If I am about 3k and floor it...... lots of pinking.

My 450 did / does exactly the same thing, ever since i bought it last year. Tends to be very unpredictable / sporadic. Ended up running super-unleaded AND octane booster which partially solved it. Eventually got round to spending a bit of time on the ignition system recently, Identified that the vacuum capsule on the distributor was loose, which doesnt do much for the timing ! Tightened it up (2 tiny torx screws) and the problem is now much less evident (dont bother with the octanne booster now and only occasionally get the symptoms). I have to say it does sound prettty alarming when it happens and one pictures holes in pistons etc Is very frustrating to have to lift in the middle of a maneouver The car is going to David Hendry next week for a service and I have asked then to take a look at this specifically.

>> Edited by tahiti450 on Thursday 29th July 10:20

[bennem]

JonRB I don't get the same thing at 5k it is definitely not a misfire. It is the distinctive metallic pink sound.

Tahiti450:- I'll take a look at the distributor. As I bought my car from David Hendry a couple of months ago I should really take it back there for them to sort out but I now live a bit too far away for this to be convenient. Hmmmm.. I wonder if I can get this done at Silverstone under warranty?

[DustyC]

You all sure its pinking?

Who is going to the Griff Growl? I have a noise I want you to hear but I dont think its pinking, sounds more like its coming from the silencer area of the exhaust. Hard to tell as its only at high revs under load, and occasional too.

(Although I sometime use Ultimate instead of Optimax).

[alex.mcintosh]

Had the same on mine when I first got it even though I was using Super Unleaded - fixed by retarding the ignition a couple of degrees. This is assuming the exhaust manifold gasket isn't duff....

[tahiti450]

[quote=DustyC]You all sure its pinking?

definitely pinking (or pre-ignition verging on detonation) !

[bassfiend]

DustyC said:

You all sure its pinking? Who is going to the Griff Growl? I have a noise I want you to hear but I dont think its pinking, sounds more like its coming from the silencer area of the exhaust. Hard to tell as its only at high revs under load, and occasional too. (Although I sometime use Ultimate instead of Optimax).

Hmmm ... since Surrey Run 5 I have been dubious of Ultimate.

Someone kindly let me have the spare seat in his Griff for that run and when meeting up with the pack at the start of the day we topped up with BP Ultimate from the garage there ... for the rest of the day *ANY* large throttle opening was greeted with clearly audiable pinking - so much so that I daren't make comment but was mentally convinced that there was something seriously wrong. On the way back (and with bugger all fuel showing on the guage) we popped in at the Shell garage on the A329M out of Bracknell and chucked in a tankfull of Optimax.

To say the difference was night and day probably doesn't even cover it ... within seconds of leaving the garage forecourt there was not a trace of pinking or hesitation. The slip road back up onto the 329M was dispatched in a manner that was only befitting 5 litres of Blackpool's finest with not a trace of pinking anywhere round to 6k in any of the first four gears under load.

Just an isolated incident perhaps but not at all a subtle demonstration of the difference a fuel can make!

Phil

[JonRB]

bennem said:

As I bought my car from David Hendry a couple of months ago

I don't think David has ever forgiven me for buying a TVR from someone other than himself, given how long my father and I have known him.

The fact that I live 75 miles from Malmsbury and Hawthorns was just down the road is entirely beside the point, it seems.

[stackmonkey]

My 5ltr was doing this, along with a somewhat louder sound at higher revs (this was the 'flapping' sound of a previous thread). booked it into John Noble in Ch'field, who sorted the general pinking and it's going back in soon to sort the high revs misfire. will post the result once it's done.

[Steve_T]

Something for you to consider, that I found out on the rolling road yesterday. The induction hose gets hot when sat in traffic, because its close to the manifolds and this definitely brings on pinking. I have ordered some wrap for the hose to hopefully reduce this problem. I'll let you know how it goes.

Steve.

[GarryM]

I've not heard that pinking is usual. I thought it was seriously bad news. The only time I've had pinking was due to the timing "going out" during a track day. After a tune up it was fine - never pinked before or since. I'd say you should get the car looked at asap.

[bennem]

Thought I would update you on what the problem was.

Feel a bit of an arse I have to say!

I took Tahiti450's advice and had a look at the connection of the vacuum advance pipe. I had previously checked that the pipe was there and connected but hadn't taken the trouble to check the housing attached to the distributor. It was looser than a loose things loose thing on a windy day.

30 seconds later and voila pinking free.

[tahiti450]

Ahhh see, listen to Papa, told you I was a smart-arse...

[JonRB]

[redacted]

[only me]

quote DUSTY C "You all sure its pinking?

Who is going to the Griff Growl? I have a noise I want you to hear but I dont think its pinking, sounds more like its coming from the silencer area of the exhaust. Hard to tell as its only at high revs under load, and occasional too."

i have this sound have checked my distributor and vacumn advance, is this pinking and what recomendations on a cure, if i acclerate hard I get it, if I acclerate steady but quickly no noise. There is no loss in performance and have been told they all do that sir by someone i trust but still niggles and worries me,
cheers Tony

[SEI Wide Boy]

I think i have the answer. I've got a 5L Chimaera, and it started pinking when pushed hard. It turned out to be one of the pipes carrying air working loosedown the left hand bank of the V8 (passenger side).

I took it to a guy i know, he spent 20mins looking at it, and tightened the hose up - AND IT STOPPED IMMEDIATELY.

Before embarking on anything detailed have a little play with the hoses, make sure there all tight.

Paul