XF Falcon running rough at startup - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

YellowXF · 05-16-2003, 04:29

Hi Everyone

I have another question about my XF Falcon. When i start it up after sitting overnight it runs like a heap of S**t. It doesnt accelerate properly, feels like it has major flat spots but after bout 1 min it is fine. I have rebuilt the carby but feel that something must be wrong. i dont know if it is the fuel filter as i havent changed it but it is really annoying me.

Any ideas greatly appreciated

Tom

Phat XLS-ute · 05-16-2003, 04:48

i have exactly the same probem!
i too recently had the carbys rebuilt
and every monring when i go to work i start it up its very rough
i think its just cause of the cold...maybe

YellowXF · 05-16-2003, 06:48

i am glad that it is not just me that is having this annoying problem

eskyboi · 05-16-2003, 07:35

Hey guys,

Have you checked the operation of the vacuum pull down.. to make sure the choke opens slightly when the throttle is opened?

Could either be too tight and not opening.. or too loose and opening too much leaning?

The last car I had was an xf.. and i adjusted the choke tention several times a year to make it work just right (rotating the heater unit to adjust choke amount).

YellowXF · 05-16-2003, 08:04

Hi Eskyboi

When the car is cranking the choke is closed, once the car starts it opens up and does it's fast idle thing and eventually fully opens after couple of mins. i have tried playing with the choke valve when the car is running bad but doesnt seem to make any difference

Sounds like they need to be adjusted for each season

cs123 · 05-16-2003, 14:51

Quote:

Originally posted by rothki
Hi Eskyboi

When the car is cranking the choke is closed, once the car starts it opens up and does it's fast idle thing and eventually fully opens after couple of mins. i have tried playing with the choke valve when the car is running bad but doesnt seem to make any difference

Sounds like they need to be adjusted for each season

A correctly operating choke doesn't need to be altered between seasons.

Dellboy999 · 05-20-2003, 17:30

I rebuilt my carby on my XF myself, full tear down and put back together, I set everything on it according to the gregorys specs, the float was a problem had a small leak so would sink to the bottom and flood the motor, once i soldered it and set it, all was fine, I did clean the fuel filter at the same time by pulling out the centre unit in the fuel tank as well.

Maybe you are low on fuel and you have water in your petrol as well ??

Dellboy999

YellowXF · 05-21-2003, 03:15

Hi Dellboy999

I have done the same as you with rebuilding the carby and set it all to the specifications in the gregories manuel. I cleaned the fuel filter in the carby but havent done the one in the tank or the one that is inline between the chassis and the fuel pump inlet. i am actually starting to wonder if it isnt a incorrectly fitted vacume hoes as it only started doing this since i had the engine rebuilt. wondering if it is a PVS. will try fuel filters

Tom

cs123 · 05-21-2003, 03:46

One thing you may want to check is correct operation of the accelerator pump jet. That will cause flat spotting. Also have you checked when the engine is cold that the choke is closed with the correct amount of spring tension and that is able to move freely.

Don't discount ignition problems either. Make sure that the distributor vacuum advance is operating of a ported vacuum source.

eskyboi · 05-21-2003, 07:01

cs123

I agree that a correctly working choke shouldn't need adjusted... but an old bimetal spring and heater unit does vary depending on ambiant temperature. Also in Qld we have constantly warm summers, and very varying temperatures in winter, thus a static choke setting is not always optimal.

As to the accelerator pump.. good call! The diaphrams do become hard after a while and are less precise on the jet being produced.

My XF used to run like shit for the first minute in winter on really cold mornings.. but that was due to failing rings and leaking down valve stem seals (nice bit of oil in each pot after sitting overnight). Once warm was fine for an 8.5sec run to 100 :)