DickieB
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| posted on 21/3/04 at 04:00 PM |
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Fuel Problems
Symptoms:
Mis-fires on exit of long sweeping corners and tight hairpins (eg Mallory Gerards and hairpin, or Donington most corners! ) Long high speed straights
are not a problem. I run a full fuel tank for all races, and the problem is from the outset, so the fuel tank is not the problem.
Action taken:
Float levels adjusted this week from 41mm to 39mm - no change, same problems at Donington yesterday as at Mallory last weekend.
Thoughts:
Pressure regulator set too low - but then you would expect high speed straights to be a problem.
Loose connection - can't find one, and the loom is well tied down, so nothing moves under "g" force
Fuel pump on way out - ? (Facet Red Top)
Anything else you can help with please?
Thanks
Dickie B / Rich Brown
Locost 71
[Edited on 21/3/04 by DickieB]
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Deckman001
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| posted on 21/3/04 at 04:23 PM |
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Is your fuel tank 'baffled' ,not confused, before any one makes a coment !! 
I don't know the tracks, but are the corners you are having probs with all left or right handers ? ie fuel starvation ??
Only a thought
Jason
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madforfishing
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| posted on 21/3/04 at 04:53 PM |
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Sounds like a baffle problem to me. Your fuel output pipe is sucking dry on those tight corners as the centrefugal force pushes the fuel to the other
end of the tank.
Do you already have a race sized tank?
I don't how much fuel you use on your races / track sessions but 2 gallons in a road cars' tank will be sloshing all over the place.
I would either get a smaller, baffled race tank or if you still want to use your road car whip the end off the tank, get a pal to TIG in 2 or 3 baffle
plates and then TIG the end back on again.
HTH
Rick
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DickieB
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| posted on 21/3/04 at 05:18 PM |
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I run with a full fuel tank at the start of each race, and the problem is from the outset, so not the fuel tank.
(Original post amended to reflect that and avoid confusion)
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Berwyn
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| posted on 21/3/04 at 06:05 PM |
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Have you got an oil pressure gauge inline with the oil switch ?, if so, does it dive when the engine is missing? fuel might be a red herring, the
problem could be the oil pump sucking air. Is your sump baffled, is it a BEC ? if it is baffled, have you modified the oil pick up to suit ?
24 hours in a day, 24 beers in a case. Coincidence? I think not
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Fozzie
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| posted on 21/3/04 at 08:17 PM |
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Hi,
further to my reply to you on the locost-racing website, Facet do a good 'fast road' pump.
Just thinking out loud, but have you checked to see if the tank 'breather' is not getting restricted when you corner?
I am still inclined to think that (assuming breather not getting restricted), that the pump you are currently running (given that it is sited near the
tank), is by far too much.
Good luck and let us know the outcome!
ATB fozzie
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Multispeed
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| posted on 23/3/04 at 06:24 PM |
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Fuel Problem
Dickie
I had exactly the same problem last year. In my case it was solved by putting a Fuel King bowl type regulator in line just before the carb. I also
made sure there was no air in the petrol line by pumping petrol through before doing up the final connection to the carb.
Hope this helps.
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DickieB
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| posted on 24/3/04 at 03:51 PM |
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I already had a Filter King pressure regulator.
I have tried everything and now bought a new solid state pump which will replace both the old pump and unneccessary regulator.
I will post again after the next race at Snetterton on Easter Sunday and let you know whether I was successful (at curing the problem not winning the
race - although I suppose theoretically the 2 could be related!!!! )
Dickie
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DickieB
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| posted on 3/4/04 at 03:42 PM |
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B*gger
Fitted the new pump this week. Just returned from Llandow. No change, still misfires on exiting long corners - various rpms from 4-6000rpm depending
on the corner. Also changed dizzy cap, rotor arm, HT leads, plugs. And raised float levels repeatedly. Still misfires.
Only remaining option seems to be the carb as everything else is OK. I'll have to try my old carb for Snetterton and see if that works.....
Dickie
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DickieB
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| posted on 4/4/04 at 05:35 PM |
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OK, so I've just changed the carbs on my engine, and replaced it with an old DGAV carb - which has an anti-stall device at the back of the carb,
opposite the accelerator diaphragm bit. The anti-stall device is linked by rubber tube to the base of the carb where there is a hole going all the
way through to the centre, just beneath the butterfly.
This device catches on my rocker cover, so I want to remove it - it does not appear to do anything useful, as many DGAV carbs do not have it. In fact
I removed it and blocked the hole in the base, and the engine started and ran fine. Except the diaphragm where the anti-stall device was leaks petrol.
To my mind, if I just put a metal plate across it as a blanking plate, this should solve my problems. Anyone got any experience of these things, or
agree/disagree with my idea?
Many thanks
Dickie
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Fozzie
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| posted on 4/4/04 at 05:55 PM |
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Yep Dickie,
The blanking plate should do it!
ATB fozzie
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DickieB
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| posted on 4/4/04 at 09:05 PM |
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Thanks Fozzie - I'll fit one tomorrow.
Does the anti-stall device actually do anything useful?
Dickie
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Fozzie
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| posted on 4/4/04 at 09:25 PM |
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Dickie,
If the car runs fine and ticks over without it, then you won't need it.
The anti stall device was introduced to meet CO regs.The cars could be run leaner to comply with regs and not stall on tick over. You say the car
runs fine since you removed it, so IMHO, you will not need it.
HTH
ATB fozzie
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Fozzie
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| posted on 12/4/04 at 05:42 PM |
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Dickie,
How was the 'fuel starvation' problem at Snetterton? Has it sorted?
Did the blanking plate 'work out'?
ATB fozzie
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DickieB
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| posted on 13/4/04 at 08:52 AM |
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Problem solved - the change of carb sorted it. I think I was down on absolute power as I did not have time to rolling road it, but at least I had
power at all times!
And guess what, I managed to finish 7th
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Fozzie
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 posted on 13/4/04 at 09:01 AM |
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Dickie,
Excellent news! Well done on your 7th place!
Now, off to the rollong road with you!!! and get some more power! lol
ATB fozzie
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DickieB
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| posted on 18/5/04 at 11:22 AM |
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Didn't have a chance to rolling road it prior to Donington on Sunday - my new exhaust manifold turned up and was sent back as it was such poor
quality. So I've now got another one (new supplier) and will get it rolling roaded.
Oh yes, and I finished 5th at Donington with 2nd fastest lap..... I wonder how much extra power I can find from the rolling road.....
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