a Tenni, now from the west

Not really sure. I got the bike at just under 42k and had full MG 40k service done straight away. Had hint of it then and was advised to bring it in if it got worse. I honestly wasn't sure if I was just tuning into the sound of the bike more but come about 46k i was sure it was getting worse and came in to Mario and it got stripped straight away. From snippets of info I have now it appears the previous owner may have got wind of it earlier and that was probably reason for it being sold but info wasn't passed through the two dealers involved to me. Buyer beware and no regrets - if it chugs on like it is now I'll be a happy little vegemite.

Conor

That's the spirit Conor. The GRiSO, he speaks to you.

to add to the story: post rollerisation (GRiSO word) -  pickup from shop, standard MG map  - awful. Woeful state, poor idle, hunting. Beetle map, all settled, lovely, very nice GRiSO.

Add 6 + months. One of my plug caps failed (while filtering traffic, dramatic at the time...). New caps. New caps. Serviced, Then....Hunting  (well more like hesitation)  at <3k revs started. Fine under any form of acceleration but just painful on freeway commute. Installed latest Beetle roller map but no real change.

Found out those lovely holes in airbox aren't actually stock but from previous owner ...taped up. Also found out airbox should also have a snorkel thingy. don't have one of those so job for later, but clearly in the 'all bets off' part of Beetle's world until corrected.

High Idle : 1400 rpm. Carbtune arrived so balanced TB's. Bleed was open a little on right when I started process. Bleed was significantly open on left by end of it. Still no good on road. Hmmm.

Didn't pick up that CO needed setting at 0 before starting process (note to self - read ALL of forum), so did whole thing again. Very significant opening on right (multiple turns open to get balanced). Idle back to ~1250 but still awful at 0. Perfect open heavy throttle as always. bit...Popping on decal. Lots of hesitation up to 3k. Changed to +8 and a little better but still not pleasant. and popping like hell all the time. Resets all done.

Will try and find snorkel to get inlet air sorted, though doubt the snorkel is the cause really. Will check valve clearances though expect should be fine given it was checked post plug cap change.  May change caps again - maybe something happening there again. So, few things to do before asking for help. Must be mechanical... & GuzziDiag doesn't seem to register clutch engagement & revs don't change as much as I remember them I(300 rpm ?)so maybe something  there playing with map.

Oh yes, minor item - pulled out that ugly little yellow painted screw on left throttle body and cleaned it up a bit before replacing ...(just kidding Pete, just kidding...paint is just as Mandello left it...)

CW

You don't need the snorkel. Many of us have removed ours to create more stash space. I can't detect any difference without it. Your TBs are good and clean?

Definitely sounds like it has an air leak. Check the clamps on the throttle body boots and if the doesn't help try replacing the inlet manifold gaskets.

The linkage rod hasn't been moved has it?

Pete

The maps are made without the snorkel. Don't bother putting it back in.

More than 40K km? Dirty TB's and possibly gunk in stepper pipes. Dirty or misfiring injector. Loose inlet boots.

Tks all.

Tks on snorkel - saves me searching for nothing.

Will give tb's / inlet / stepper etc a good seeing to next. Don't think linkage has moved - not deliberately anyway. Would misfiring injector be more likely to be consistent through rev range ?

I've been thinking about that. If it was misfiting, yes. If it has a partial blockage, maybe not. If one plug is a substantially different colour (lighter) it indicates a lean condition. If one is very dark or black, it suggests a spark issue. Running lean in one cylinder may or may not give an increase in vibes, but may induce pinging

Another thing to check is TPS at WOT with Guzzidiag (engine not running of course). Confirm it reads 85. Also, check the TPS angle rises smoothly from closed to WOT.

Righto - tks Mark - will check all that and report back...

Nice bikes Conor....and welcome.

Tks 1151. Been here a while now - so should have put latest story in tuning thread. Will continue my troubleshooting saga over there !

Well, if that is not par for the course for me today!

Overslept this morning and was an hour late to work too!

Cheers,