beetle developed a flat spot when fueled with 98?

lohoon Wolfsburg Wizard

466 posts · joined Sep 2002 · 17 Jun 2006, 6:17 pm

#501676

I drove about 550klm today in a very noisy baja.I was almost empty and i put half a tank of 98 bp fuel in her and by the next set of traffic lights she had developed a flat spot where you had to feather the throttle to try to drive out of it.
On the way home i again almost empty filled her up with the cheapest unleaded and again almost immediatly the hesatation/flat spot was gone? Any ideas?

barls Administrator Causer of Chaos and Mayhem

9,474 posts · joined Jun 2004 · 17 Jun 2006, 6:20 pm

#501679

too high an octane for the way its been tuned maybe what has it been run on before this

“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me

lohoon Wolfsburg Wizard

466 posts · joined Sep 2002 · 17 Jun 2006, 6:25 pm

#501683

It usually just gets the 92 rated fuel

Anthiron The Baja Rejuvenation Begins

4,936 posts · joined Oct 2003 · 17 Jun 2006, 6:30 pm

#501688

then just run 92 in it.

usually with the 98 u can run the timing a little more advanced. which is what i do.

62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
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VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 17 Jun 2006, 6:32 pm

#501691

98 doesn't evaporate as quick, and burns slower - hence the flat spot. No problem in a knock-sensed car, no good in a carby-fed low-comp donk like a VW!

[ Edited on 17-6-2006 by VWCOOL ]

Pay your debts, CxxT

barls Administrator Causer of Chaos and Mayhem

9,474 posts · joined Jun 2004 · 17 Jun 2006, 6:37 pm

#501694

unless the timing is adjusted

“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 17 Jun 2006, 7:08 pm

#501706

barls wrote:unless the timing is adjusted

yeah, 98 likes lots of advance

Pay your debts, CxxT

bond Veteran Volks Folk

2,456 posts · joined Jul 2003 · 18 Jun 2006, 10:38 am

#501849

and high comp?!

PrettyBlueBug Almost over it...

2,032 posts · joined May 2005 · 18 Jun 2006, 2:04 pm

#501894

My Bug loves 98 and 100 octane... :P

sinecure Want another... :(

1,031 posts · joined Mar 2006 · 18 Jun 2006, 2:35 pm

#501902

As long as it's tuned for higher octane it's no problem to run 98. Timing is critical as others have mentioned.

A POSSE AD ESSE.

I live in my own little world, but it's okay, they know me here.

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 18 Jun 2006, 5:36 pm

#501954

bond wrote:and high comp?!

yeah, which kinda makes it a waste of $ in a stock VW

Pay your debts, CxxT

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 18 Jun 2006, 6:38 pm

#501987

I run 98 octane in My Beetle....

No Problems....

Lee

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---