Valtra
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 posted on 17/7/08 at 07:40 AM |
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fuel problem ?
Hi my car is now registered but it broke down a couple of times on it's first journeys last night , spluttering to a halt with what seemed
like fuel starvation , but after a couple of mins rest it started again quite hapily , there doesn't seem to be any vacuum build up in the fuel
tank ( has a one way breather valve) and no apparent leaks . the fuel system is a mixxed bag of second hand and refurbished parts . Facet pump
-filterking-twin forties. I've turned up the fuel on the carbs since SVA but it flufs a bit at low revs before clearing it's throat and
going , could it be pressure , if the filter king is too restricted? any thoughts greatly apreciated
Ian
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coozer
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| posted on 17/7/08 at 08:04 AM |
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Hmm, i had similar problems on my Fiat TC with 40's in my Striker... it used to stop then I would flatten the battery trying to start it. After
recharging the battery it started no problem.
I put it down to the 40's overfuelling in some areas of the rev range and under fuelling in others. This all resulted in the engine flooding
with petrol and the time to recharge the battery allowed it to dry up. All this happened even though I'd spent some time on the RR.
So, your looking for a fix? Sorry all I did was take it out and put a Montego turbo engine in.
Have you considered a bike carb conversion?
1972 V8 Jago
1980 Z750
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mr henderson
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| posted on 17/7/08 at 09:51 AM |
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Could be a blockage in the fuel supply that is floating away from the blocking point when the car rests (happened to me with a pre-crossflow Ford I
was convinced the problem was electrical but it turned out there was some rubbish in the float chamber)
Or it could be electrical, sometimes components such as capacitors get hot, fail, when they cool they start working again (happened to me with an old
A series)
Sounds like some forensic investigation is called for while the engine is still in failure mode. Try whiping a spark plug out next time it happens. Is
it wet (with petrol) does it spark when the engine is cranked and the plug is earther against the block?
John
[Edited on 17/7/08 by mr henderson]
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Davey D
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| posted on 17/7/08 at 10:08 AM |
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On my old fiat Uno it started playing up when on a drive.. it reacted like i was running out of fuel... the car would lose all power and start slowing
down to a crawl... if you let the car cool down then it would be fine to start, and run again.
In the end it was the electronics in the distributor that was breaking down when the engine warmed up. It is a common problem aparently, and once i
fitted a new one then the problem went away :-)
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graememk
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| posted on 17/7/08 at 11:11 AM |
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i had a prob like that with the indy and again it was the coil
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Dusty
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| posted on 17/7/08 at 12:22 PM |
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If your Facet pump is the solid state one with the facet prefilter. Ditch the prefilter and use a cheapo plastic cartridge one. The facet ones block
very easily.
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Valtra
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| posted on 17/7/08 at 04:47 PM |
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Thanks everyone . bit more info , the ignition is Lumenition competition spec with matched high power Lumenition coil bought second hand and fitted
with fingers crossed but the car starts and runs so must be working , I had the wrong radiator cap fitted without a rubber seal which caused it to
overflow onto the ignition system a few times but that was cured before the current round of problems , I still suspect fuel, the facet is the larger
barrel type (red top if I remember right) which also has a cartridge pre filter between it and the tank . The Filterking has a bit of adjustment is
that a possibility?
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mr henderson
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| posted on 17/7/08 at 04:59 PM |
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quote:
Originally posted by Valtra
The Filterking has a bit of adjustment is that a possibility?
Not really, not unless your problem only occurs during periods of heavy fuel use
John
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Valtra
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| posted on 17/7/08 at 07:20 PM |
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Thanks fellas. Touch wood it never hapens again ....Mmmmm
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Valtra
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| posted on 12/8/08 at 07:50 PM |
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200 miles under my belt now . still having a few breakdowns it seems to be worse during low speed running once fully warmed up . miss-fires and poping
and banging if you catch it quick enough and rev it . the car splutters then revs cleanly and accelerates then when you back off again back comes the
poping and jumping. The car is still running un-known jets and roughly set up timing .
Thinking out loud , is it worth turning down the fuel a tad so that it runs rougher at first then once warm it's not choking on perhaps too much
fuel ?
as usual all your contributions greatly apreciated.
Ian
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flak monkey
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| posted on 12/8/08 at 07:54 PM |
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Take the jet covers off and pull the jets out, post up what they are and I'll tell you if they are roughly right. Your idle jets could be miles
out, but would usually play up all the time.
Defo sounds like fuel starvation. If its too rich you will get black/grey smoke from the exhaust when the throttle is blipped. Too lean and the carbs
will spit back (not backfire!).
Check the timing with a strobe would expect a good starting point to be around 10deg BTDC.
David
Sera
http://www.motosera.com
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flak monkey
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| posted on 12/8/08 at 07:56 PM |
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Where in the world are you, someone might be able to pop over and give you a second opinion.
Sera
http://www.motosera.com
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Valtra
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| posted on 12/8/08 at 08:05 PM |
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Thanks for that info I'm on the Lincs/ Cambs border nr Crowland
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omega 24 v6
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| posted on 12/8/08 at 08:29 PM |
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Not usually a problem at this time of year but I have seen the carbs icing up. Or fuel vaporisation due to heat. Or try running with the filler cap
off altogether (just in case there is a vacuum )
If it looks wrong it probably is wrong.
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Valtra
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| posted on 12/8/08 at 08:35 PM |
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Thanks , but hard acceleration seems fine so surely tank vacuum would nobble that, I have a (motorbike) one way valve tank breether also
"If it looks like it works and it feels like it works, then it works"
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flak monkey
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| posted on 12/8/08 at 08:50 PM |
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Hard acceleration with fuel starvation usually temporariliy overcomes it with 40's due to the pump jets.
Found this out myself after my breather pipe got kinked the other week 
Its worth going for a run with the fuel cap off or loose to see. Either that or drive till you get a problem then pullover and remove the cap, if it
sucks air in then you have a problem.
If I get a free evening I could pop over and have a look, given some decent weather, you arent far from me anyway. Friday would be a good day, U2U me
and we can arrange something if you want?
David
[Edited on 12/8/08 by flak monkey]
Sera
http://www.motosera.com
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Valtra
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| posted on 12/8/08 at 09:01 PM |
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Cheers David
I'm harvesting (weather permitting) at the moment so can't make arrangements very far in advance, unfortunately for this situation good
driving weather is usualy good combining weather also, but it's very good of you to offer . will u2u my postcode anyway cheers
"If it looks like it works and it feels like it works, then it works"
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DarrenW
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| posted on 13/8/08 at 08:09 AM |
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Ive hd similar problems before in the early days.
1. Car would run fine, then start to splutter, then die. Would start up but gradually got worse and worse. This turned out to be the ignition
amplifier. Changed for 2nd hand Motorcraft (OE) one and it was fine again (2.0 Pinto on early type electronic ignition).
2. While using 38DGAS carb, on heavy acceleration under load car would miss. Turned out to be blocked fuel filter. Crap from drilling the tank to fit
sender unit (even though i was careful) had found its way into fuel filter. Changed it and all was well.
Only other problem i had with DGAS carb during car build was when using facet red top pump - way too powerful and regulator couldnt cope with the
pulsing of the pump even though turned right down. This caused engine to flood, plugs to soot up etc. Changed to mechanical pump and all was well.
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02GF74
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| posted on 13/8/08 at 01:09 PM |
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check also you don't have an air leak on the inlet side - you are using thackery washers and have done them up correctly? and if using the
rubber 0-ring spacer, are the o-rings in place?
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Valtra
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| posted on 13/8/08 at 07:08 PM |
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up date ....
the jets are
long ones .f49
short ones 50 f26
not using thakeray washers, using the rubber jobbies may need tighteneing a tad they all have a 2-3mm gap between the plates . do get the occasional
pop and spit back through the carbs, but I put it down to old school tech.
cheers
"If it looks like it works and it feels like it works, then it works"
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Valtra
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| posted on 14/8/08 at 12:51 PM |
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just pushing up the page
"If it looks like it works and it feels like it works, then it works"
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flak monkey
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| posted on 14/8/08 at 02:38 PM |
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Sorry for not getting back to you last night.
Ok the short ones are the idle jets and holders. These control the mixture upto about 2,500rpm or so. 50F9 are the best starting point, and yours
arent far off that.
The long ones are the main jets and emulsion tubes. From your numbers it sounds like you have webers and not dellortos. The long ones should be in 4
parts. The screw in holder (the top bit), the main jet (the bottom bit), the emulsion tube (the middle bit) and the air corrector (fitted to the top
of the emulsion tube, under the holder). Expect the main jets to be around 140's and emulsion tubes to be F16/F9 or F2.
Spit back is leaness on that choke, timing miles out or valve clearances wrong.
Cheers,
David
Sera
http://www.motosera.com
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flak monkey
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| posted on 14/8/08 at 03:12 PM |
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PS Valtra, you have U2U 
Sera
http://www.motosera.com
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Valtra
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| posted on 14/8/08 at 05:55 PM |
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Cheers David
So do you , I'll whip out the mains again and have a look if I can strip them down to find some more numbers ...or even better .... a few
earwigs and hedgehogs blocking them . 
cheers
Ian
"If it looks like it works and it feels like it works, then it works"
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Valtra
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| posted on 14/8/08 at 08:42 PM |
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Main tube f49
top hole (under holder) 135,
hex end 115
no hedgehogs.
cheers
Ian
"If it looks like it works and it feels like it works, then it works"
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