View Full Version : Fuel starvation & serge
In my racing car i have found that once i get to the last 1/4 of a tank i am suffering fuel starvation exiting left hand corners only....
My car doesnt have a reserve tank fitted which wont help.
The car doesnt have any fancy fueling components either so its all stanarad williams stuff.
Does anyone else have this problem or is it something that im going to have to live with and run more fuel to cure ???
Fitting a banana style tank isnt a option unfortunatly !
Can anyone help with a cure ?
When you say fuel starvation, what do you mean? Like loss of power?
On mine sometimes at higher revs it starts to feel a bit flat.
Wondering if it's maybe related.
no - acelerating out of a left hand corner - it splutters as if there is no fuel then once its settled it pulls again - does it for around 2 - 3 seconds.
I imagine its the fuel swasshing from corner to corner.
maybe increase the fuel pressure slightly so the fuel gets there quicker?
can that be done at home ?
Has it got the early Ph1 tank? ....they have real shitty pumps ...more or less the same as the washer pumps
My car is pre any phase mate - its a preproduction race car to promote the clio.
If it was registered it would be a H reg i think.
So does this mean that there is a differance in working pressures between the phase one pump and phase two pumps ???
Do you know what the pressure was changed too ?
i know the fuel pressure is supposed to be 3bar on the ph2 iirc,
to increase the pressure you'd need to either buy and adjustable fuel pressure regulator or a different fuel pump
Mmmmm. Will try a phase two pump first i think before i start on them Rich....is it a direct swap winston ?
afaik it isnt no, bayliss's is a ph one and the assembly of the pump ect looks totally different to mine
Different tanks ....... Ph1.5's and 2's fuel pump and sendor fit in the top of the tank
Early ph1 pumps are not much from Reno iirc
Ph1 ......H-J - little pumps under the tank
Ph1.5 ...k-L - 1.2 bar top of the tank
Ph2 ......L-N - 3.0 bar top of the tank
not sure gaz, where does that fit ??
Will get under the car thursday and have a look for the pump....all good info - keep it coming !
be careful if you pull the pumps out northy ...as they have pin that goes in to the tank this can break very easy....the new ones from reno are an up dated design
Might not even be anything to do with the pump :oops: :roll: :P lol
Actually in the tank, this is what mine has in it. Presume u can just feed it in??
yours will have that built in gaz - dont think i could feed that in a standard tank.
i had this also, just when i was getting well empty on fuel at cadwell northy.
mine is a J plate, so early phase 1, but i currently have the aux tank although i wanna get rid. i reckon the pump is just a little crap.
could prob try fittin a walbro (or similar) uprated item, or you just run with more fuel. :wink:
am i not correct in saying that you need to carefully cut the metal above the tank to get access to it, so you can fit the new pump?
was ur fuel starvation bad? mine just hesitated and kinda spluttered/jerked for an instant, then was fine. came in lap later and went and got fuel.
it was like a loss of power and spluttering - i just backed off and feathered till it settled. like it was choking up. had it first at fcs then brands - but discovered what caused it when i got to the last 1/4 of a tank from full.
not a big problem but i would like to run with less fuel in at some stages :wink:
no point uprating pressure...if the fuel isnt there...it isnt there!
maybe modify the pump so the pick-up is lower?
or fit a swirl pot?
does anyone have a exploded view of the pump and pick up point ?
if no-one has already...i can take a pic of one and have look see what could maybe be done.
im off today...but i will be popping over to workshop later on...so give me a couple of hours.
cool.
Yours is a willy 1 ????
http://img48.imageshack.us/img48/9599/30102006sg3.th.jpg (http://img48.imageshack.us/my.php?image=30102006sg3.jpg)
http://img113.imageshack.us/img113/4166/30102006001jw4.th.jpg (http://img113.imageshack.us/my.php?image=30102006001jw4.jpg)
yup mines a williams1.
right, in the tank, surrounding the pic-up filter, there is a plastic baffle which will help prevent surge. i dont no whether these are in all tanks etc as ive never looked...but it would be worth checking you have one.
aside from this, it doesnt look like u could extend the pic-up filter, as it sits nigh-on on the bottom of the tank. and if u check the pics out, you can see it would be awkward.
so aye, i would first check u have that baffle.
how low was the fuel level when u were getting surge?
the needle was showing around 1/4 left stan.
Thanks for the pictures - will have a look in my tank to check i have that baffel.
Will also need to check my handbook to see if the comp cars ran a standard set up !
sa said, messing with pressures and pump units wont solve surge.
phs1 units have the tank bias to the left side of the car, and when you turn left fuel will settle on the right, nowt you can do with a quick fix.
retrofitting the phs2 tank i've never tried, so i dont know if there are any wiring incompatabilities due to single pump/sender unit.
just run with more fuel in it, easy fix.
Im going to Ben - at first i thought it might be a problem with the car as Aarronc's doesnt do it.
Early Ph1 valver tanks don't have a pumps like that :S ....The pumps no way near the sendor unit like the pic, but god knows what tanks in your car northy
All Ph1.5 and 2 have that plastic baffle in the tank
easy way to tell is to take pic of the top of the sendor and i will be able to tell what tank you have ...I'll get a pic of my Ph1 when im next at the yard
But if you wish to convert to a ph2 tank ....Ive got a full set up you can have for free if you come and get it out my face lol
first dibs on that!
My clio is dead as the fuel pump died and i've been too lazy to drop a tank full of fuel.
Is the plugs/loom compatable?
i've never swapped over the tanks between phases.
ok, will get a picture on friday !
Not sure how easy they are to swap Ben ....mounting points are the same tho ...fuel lines may be different :?
Im going to have a good look when im next at the yard ....my mates got the key :roll:
cool, if ya could check that would be sweet.
All this talk of fuel pumps and pressure and shizzle. Don't you just need a swirl pot?? Or baffles in your fuel tank.
I've never had any experience of such devices but that's what I've read the racers use for that same problem.
Hows fuel pumps or increased pressure gonna help if theres no fuel to pump :?:
pressure wont help, nor will a new pump, but that has been establised.
And running a swirl pot would require a second HP pump to feed the rail as you'd be relegating the original pump to lift duty, plus messing around a bit with fuel lines.
And baffling a plastic tank isnt worth the effort.
^Fairdoos. In a car builders catalogue I've seen foam that you cut to size and fit inside your fuel tank. supposed to prevent explosions and also act as a baffle. Maybe that would work?
early tanks have the sender under the cover and to the drivers side the pump just like the 19's.
All EFI tanks have the baffle in them.
The wiring, the late style integrated pump and sender uses 1 plug, the earlier one has a fly lead extending to the senders plug but still uses 2 plugs.
But yes you can mod it to suit.
ran with more fuel in the end - no problems throught the day !
Fit a swirl pot and an aux pump from teh swirl pot to the fuel rail
the more fuel is the best all round idea though, certainly the least expensive and hassle free!
the more fuel is the best all round idea though, certainly the least expensive and hassle free!
But it makes you go slower :twisted:
New fuel pump fitted and the car was alot better. I could run under 1/4tank. How ever there was not too many fast hard left hand corners to check for comparrison.
Next trackday is oulton park in august - that will be my real test!
New fuel pump fitted and the car was alot better. I could run under 1/4tank. How ever there was not too many fast hard left hand corners to check for comparrison.
Next trackday is oulton park in august - that will be my real test!
I ran 1/2 to 3/4 all day at 3 sisters at the rally at the weekend and had no issues (well fuel ones!). All the morning stages where the opposite way round so all left handers. Only thing was that it was raining all day so no where near the g's you get when in the dry, plus only 3 min stages not 8 mins like Angelsey.
May sort the pump out anyway but will be trying yje 1/2 tank method for the next couple of rallies..
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