As title says,, i'm pretty sure my 5 shouldnt be drinkng so much fuel. Im dont mind how much fuel it drinks if boosting about, (its been tuned for 20psi) but normal driving is not good!.
for £10 petrol, i get around 22-24 miles. Is this right? and can i do anything about it?
No it aint right, have you checked for leaks?
used to have a fuel leak on the tank.. but sorted that. No smell of petrol anywhereOriginally Posted by Bigfoot
used to have a fuel leak on the tank.. but sorted that. No smell of petrol anywhere
As Dale say's defo not right matey £10.00 must get you about 1/4 of a tank nowadays. My 5 which is setup for 22psi manifold I see about 50ish+ miles to 1/4 of a tank dependant on driving style and traffic etc.
Has your 5 always been like this??
pretty much ye
what should i look for? can't be anything to do with tuning the carb better for off boost? i dont think its a leak??? cos if i put petrol in it and dont drive the car,,, the petrol doesnt go down
pretty much ye
what should i look for? can't be anything to do with tuning the carb better for off boost?
Apart from the bad fuel economy does the car idle and drive fine? any hesitation etc..
If you have no leaks I would be looking into the size of the jets in your carb specifically the main jet and size of the 1st stage, needle jet is it sealing properly, i would be also tempted to take the carb lobster off whilst car is idleing and seeing if any fuel is overflowing out of the bowl? how old is the carb gasket set?
Borrow a wideband kit and see what afr's you are getting on off boist driving? idle? and @ WOT aswell
the car seems pretty much fine on idle and off boost... Maybe the slightest hessitation when moving off sometimes... but i dno if thats to do with anythin. Its not bad at all really. im not good with carbs really, but js had it set up for 20psi. Its js the offboost fueling now thats makin me annoyed. Ive had Marky Mark set up the fueling for boost, but he lives far from me and driving there is alot of petrol for me! :P hmmm
i'll ask Mark what jets im using.. maybe he'll knowthanks for the advice tho.
well i get 38 miles out of £20 pounds so that aint that bad really isit? i have just raised the boost to 14psi
the car seems pretty much fine on idle and off boost... Maybe the slightest hessitation when moving off sometimes... but i dno if thats to do with anythin. Its not bad at all really. im not good with carbs really, but js had it set up for 20psi. Its js the offboost fueling now thats makin me annoyed. Ive had Marky Mark set up the fueling for boost, but he lives far from me and driving there is alot of petrol for me! :P hmmm
i'll ask Mark what jets im using.. maybe he'll know
I am sure Mark would have only fettled with the 2nd stage and possibly the a/c jet for on boost driving at that level of boost the rest of carb jet's would more than likely be standard.
Hesitation when pulling off could merely be the accelerator pump rod needs adjusting (using the 5mm drill bit method).
Are you sure you just don't have a very heavy right foot
not funnyI am sure Mark would have only fettled with the 2nd stage and possibly the a/c jet for on boost driving at that level of boost the rest of carb jet's would more than likely be standard.
Hesitation when pulling off could merely be the accelerator pump rod needs adjusting (using the 5mm drill bit method).
Are you sure you just don't have a very heavy right footits like i drive 3.0litre car
not funny
This is a standard sized venturi carb i take it??
I think the best place to start matey is getting afr results on idle, part throttle & WOT/Peak boost
Last edited by James5; 14-09-2010 at 13:44.
yep std venturi.
thats my next step. Does anyone know of anyone near me (NW London) who can help?????
When i looked at Slims car for him to get it to fuel right for 20psi i fitted a 1.0mm a/c jet as with the 1.25mm jet it was abit lean. At full throttle was seeing 11.7-11.9 which i mentioned to Slim saying it was ever so slightly rich but as he was planning to turn boost up even more we decided to leave it at.I am sure Mark would have only fettled with the 2nd stage and possibly the a/c jet for on boost driving at that level of boost the rest of carb jet's would more than likely be standard.
Hesitation when pulling off could merely be the accelerator pump rod needs adjusting (using the 5mm drill bit method).
Are you sure you just don't have a very heavy right foot
Off boost it didn't seem too bad, only really dipped slightly rich when flooring it but nothing too major.
I don't know the spec on the other jets as we never took it apart, can't say what main jet was in there and apparently its been drilled to 1.3mm on the 2nd stage.
Mark.. From what you were seeing off boost,, should it be better (mpg) than what im currently getting?? then this points towards more of a leak?? (that i cant see)
I'm just trying to remember what i was seeing off boost, was concentrating really on what it was doing on boost to be honest.
If it was using £10 worth of fuel in 23miles i think i would have expected to see really low AFR's or have noticed something very odd with the readings. .
maybe i should change all fuel pipes?? cos the old ones look like they need changing.. got slight cracks.
Have a check to see if it is leaking first though, least it'll eliminate the lines.
i'll check,,, but im doubtfull of any leaks. Unless its a really small leak that doesnt actually leak, but may leak vapour or leak only under pressure ? :P
Ok guys.. I will be changing the fuel line for a new one. hoping that it may be a small split somewhere. Does anyone know if it can leak from either the filter or pump? If anyone else has any other ideas or advice let me know... in the mean time.. i'll change the pipe and update when done.
can someone tell me if I'm ok to use rubber hose for fuel line?? Ive js read it should be copper?? I currently have some rubber hose :P
You mean replace the entire solid line under the car with rubber hose? not sure to be honest but you can pick up a small reel of 10mm copper piping or some such size for not alot and run a new line with that.
ahh yes i get it now.
I always go to carvan shops for my copper line if that helps
"caravan" ??I always go to carvan shops for my copper line if that helps
Is there anyone near me who has a AFR meter thingy?? North West London...
Sounds like an enrichment diaphragm (the triangle shaped block with a brass nipple and hose attached to it) could be leaking...
How was the car after Mark tweeked it?
Also has this issue developed over a period of time? ie has the economy just got worse day to day...
to be totally honest.. i cant remember.. the car has been off road for most of its life! Mark just made sure the fueling was ok for 20 psi.. i just want to see what the afr is off boost.. so i can eliminate a possible leak in the fuel line somewhere :S but seems like there isn't anyone near me. So i have to take long (expensive) trips to someone who can!
Having a word with Slim on pm it sounds like its been like this for a while now, poss remember saying even with another carb on there but may have to double check with him on that bit.
Its a shame this was mentioned after i'd seen the car as could poss poss done something at the time but never mind, easily forgot about sometimes.
Thank you so much for your help mark. IT is MUCH apreciated. To be honest.. i never forgot.. ive been complaining to people like my bro that my car drinks sooo much.. but he and other people say things like "ye i know so does mine" so time went by thinkin its normal...n i js thought bloody hell these 5's are riddicilous on fuel
Having a word with Slim on pm it sounds like its been like this for a while now, poss remember saying even with another carb on there but may have to double check with him on that bit.
Its a shame this was mentioned after i'd seen the car as could poss poss done something at the time but never mind, easily forgot about sometimes.
my car seems to drink fuel aswell. Or it could be the price of v power! If i put in 25-30 quid i get about half a tank. After that the needle jumps down pretty quick. Does this sound right?
And when its past quarter it just drops rapidly. Ive drove the car with the needle on the bottom of the gauge a couple of times. My red light doesnt come on. I should check the bulb really.
If 25-30 quid doesnt sound right for half a tank do you think i should replace the sender?
My car is running 21psi and its the off boost driving that annoys me to, when im boosting i expect the needle to drop.
25-30 quid for half a tank sounds ok. Just depends how many miles you get out of it that counts.. not how much it costs to get half a tank...
are you just going by the fuel gauge or do you completely run out of fuel to know what sort of mileage you are getting? Are you sure that the tank is actually empty or the gauge is lying?
Quick question to all..
How many miles am i suppose to get (offboost driving) on 1/4 tank (£10)???????
p.s. ive changed a lil pipe,testing now..
Last edited by Slim; 17-09-2010 at 19:31.
ok, Quick update,
I have since changed the rubber fuel pipe from tank to the filter, tightent and sealed a few holes on exhaust and also slightly turned the idle jet inricher to slightly less rich.
Ive managed to get 38 miles from £11 (driving off boost, except 1 time of 2nd and 3rd gear quick boot)
Is this ok??
about 19mpg if your fuel was costing 1.20 / litre. so, not great !ok, Quick update,
I have since changed the rubber fuel pipe from tank to the filter, tightent and sealed a few holes on exhaust and also slightly turned the idle jet inricher to slightly less rich.
Ive managed to get 38 miles from £11 (driving off boost, except 1 time of 2nd and 3rd gear quick boot
Is this ok??
If I'm right that is around 10l / 62km which I think is much.ok, Quick update,
I have since changed the rubber fuel pipe from tank to the filter, tightent and sealed a few holes on exhaust and also slightly turned the idle jet inricher to slightly less rich.
Ive managed to get 38 miles from £11 (driving off boost, except 1 time of 2nd and 3rd gear quick boot
Is this ok??
I've just driven 330km with mine on highway @110-120km/h (70-75mph) and drinked ony 28l.
thats not good at all...ok, Quick update,
I have since changed the rubber fuel pipe from tank to the filter, tightent and sealed a few holes on exhaust and also slightly turned the idle jet inricher to slightly less rich.
Ive managed to get 38 miles from £11 (driving off boost, except 1 time of 2nd and 3rd gear quick boot
Is this ok??
i can get silly miles per tank if driven very carefully...
slimzzy just get lighter shoes
This is making me very sad guys
I took mine to Germany and back and got at cool 36 MPG out of her, I am running a T2/T25 about 18 PSI of boost, ok I drove it at the speed limits but was well happy! (markey mark set it up)
OK OK i know already!! its running crap!!!
but it can be fixed by rtoc fairies..OK OK i know already!! its running crap!!!
those are just fairy tales. I always get a problem that is stupidly difficult to find out wats the cause!!but it can be fixed by rtoc fairies..
Posting Permissions
Reply With Quote
