well the problem is when i go around corners a little enthusiastically sometimes the engine will suddenly try and cut out mid corner. is this because of the orientation of the weber carby? the float is moving under cornering G's? if so what can i do about fixing this problem....i have noticed it doesnt do it under light throttle, only seems to do it with the secondary open.

well the problem is when i go around corners a little enthusiastically sometimes the engine will suddenly try and cut out mid corner. is this because of the orientation of the weber carby? the float is moving under cornering G's? if so what can i do about fixing this problem....i have noticed it doesnt do it under light throttle, only seems to do it with the secondary open.
ure problem, and the answer u gave is correct, due to its orientation, it cuts out.
one reason why when i found out about it yrs ago i didnt do it.

as to a fix....

I don't mean to sound patronising or anything, but this is also happening on a full tank of fuel? sometimes on a low tank the sender unit will be starved, if the fuel in the tank swells to one side on hard cornering.

the car would reduce revs hard cornering despite having a full tank or not due to float orientation. the xf weber is from an engine angling for rwd setup, so the float is facing the wrong way.
sorry if u knew that, but gives an fyi for all who didnt.

OK, that's interesting, thanks :)

the only thing i can think of as a fix, which i dont know how great it would work, would be a bigger fuel pump, may compensate fuel flow thru the corner by pumping more thru and thereby reduce the amount of rpms dropped in cornering, making the car stiffer to sway less would help.

bought all i can think of, but i somewhat doubt changing the fuel pump would work, ud then have a rich run carb, so... ehh :confused:

dont give up on ur carby.. if enthusiastic is ur problem uve got a long way to come.. ne one who knows how i drive will know enthusiastic isnt the word to use for me at all..

my point is i can make my carb get fuel cut.. or i cant.. S bends at 120 kph or 90 degree corners flat stick in 2nd it comes down to how ur float level is set. also think about ur car.
is it quake proof? does it have alot of body roll? r u just too rough?

food for thought

jaydee

dont give up on ur carby.. if enthusiastic is ur problem uve got a long way to come.. ne one who knows how i drive will know enthusiastic isnt the word to use for me at all..

my point is i can make my carb get fuel cut.. or i cant.. S bends at 120 kph or 90 degree corners flat stick in 2nd it comes down to how ur float level is set. also think about ur car.
is it quake proof? does it have alot of body roll? r u just too rough?

food for thought

jaydee

yeah it does still suffer from some body roll, but its a lot better since i installed kyb shocks all round.
chichanes, and high speed corners are normally fine its just the sharper ones with too much throttle that makes it stutter.

try coming in strong and backing off through the apex of the corner then hitting it again once ur out of the tight spot. apply ur speed in the right areas and dont break mid corner. also think about enertia and the way the car sways, come out before u go in and make the corner into more of a straigt line. find your line of best fit, just dont do it with 35 series tyres coz ur bound to touch sumthen.. speaking from experience here.. :rant:

jaydee

yeah i normally brake, then take wide smooth arc's as much as possible and power out of corners. but somtimes u just want to plant the right foot on the loud pedal and get some rally action :badgrin:

lol yeah when i was auto i used to force it to understeer using the low gear.. was great fun till they all broke :)

hehe yeah its good fun hey.
do your synchro's crunch sometimes when u shift from second to 3rd at 5000rpm ?

rich

A huge fuel pump wont make the car run rich, you need to understand how a carburettor works and you will see why it wont. :nuts:

I think that the float level is partialy to blame here, it needs to be increased probably another 5mm. Fuel pickup is rulled out because you say it happens when the tank is full.

What is happening is that the jets being on the side of the corner the fuel is forced away from them on right hand turns and therefor the jets dont fuel the emulsion tubes and you lose power.

You can buy flat floats and then baffel the bowl which will solve the problem, as ive done it before and will be doing it again shortly because i am building up a weber atm.

A huge fuel pump wont make the car run rich, you need to understand how a carburettor works and you will see why it wont. :nuts:

I think that the float level is partialy to blame here, it needs to be increased probably another 5mm. Fuel pickup is rulled out because you say it happens when the tank is full.

What is happening is that the jets being on the side of the corner the fuel is forced away from them on right hand turns and therefor the jets dont fuel the emulsion tubes and you lose power.

You can buy flat floats and then baffel the bowl which will solve the problem, as ive done it before and will be doing it again shortly because i am building up a weber atm.

thanks jason, yeah it happens regardless of the fuel in the tank. what do you mean by "baffel" the fuel bowl ?

insert copper sheets which restrict the fuel from sloshing around, trouble is that the float hits them if you dont get a nitrophyl float.

A huge fuel pump wont make the car run rich, you need to understand how a carburettor works and you will see why it wont. :nuts:
in going with the assumption he hasnt changed the jets in the carb i made that remark.
last i read he still had the jets that came with it.

if you have changed them tm terror, then my error on saying that.

fuel pressure doesn't affect the flow of jets or the fueling of a carburettor.

i heard the weber runs best with 4 psi of fuel supplied to fuel intake on the carb. so thats what i set my fuel pressure regulator to. and the jetting is pretty good, 65/70 idle jets, 132 main jet and 160 secondary fuel

dave at rpw has oxy sensored my mixture at idle and said its fine. although i think its slightly rich..
he said 135 main jet is perfect, and the secondary is best to be 145 approx.

hey tm terror soz i didnt reply when u asked.. yeah my synchro USED to crunch from 2nd - 3rd altho that gearbox literaly blew up a month ago.. it was a perfect box till i started chirping 3rd gear in it.. ahhh welllsssss all in good fun. my current gearbox is almost perfect yet it will not shift into 2nd gear above 6500 rpm which is abit of a let down -_- **** happens i guess...

try adjusting your float level.. with a pair of pliers.. ;)
depending on how patient you are and how well you can tune your webber you will make it run perfect. BTW im using the standard 34-38 webber from a auto XF 4.1 litre, no jets changed at all. car runs awesome idles perfect has the choke working the lot. so i cannot stress to you how much adjustments count. good luck with it.

jaydee

i heard the weber runs best with 4 psi of fuel supplied to fuel intake on the carb. so thats what i set my fuel pressure regulator to. and the jetting is pretty good, 65/70 idle jets, 132 main jet and 160 secondary fuel

dave at rpw has oxy sensored my mixture at idle and said its fine. although i think its slightly rich..
he said 135 main jet is perfect, and the secondary is best to be 145 approx.

try a little higher pressure, i run 8psi but my carbi is far from the average.

maybe 6.

what does the stock FPR hold pressure at?

UPDATE:
well the magna has be p**sing me off with the rough running when i need to accelerate hard lately so i thought id have another go at getting it to run right. anyway i just made an adjustment of the float in the carby by around 1 mm at the needle which makes about 3mm difference to the float and took the car out for a spin.

and now i cant get the smile off my face :D its running like a shower of s**t ! this is one psycho first gen magna !

before it would reach about 4500 in second gear and start to splutter and lose power, now it pulls hard to 5 grand running beautifully all the way (i havent taken it higher because its still a pretty fresh engine, although the way it was pulling id say 5500 would be no prob at all)

0-80km/h takes no time at all maybe maybe 5-6 seconds ? id love to see what time i could do at the drags:badgrin:

so to anyone with an XD-XF weber conversion i highly recommend playing with the the level of the float to get more fuel !

My advice? Return the car to bog standard and all your problems will be solved. The days of "I've got a hot car because it has a Weber" are long past! lol