Focus 2004 jumping

[johnny2007]

Hi everyone, my old focus 2004 has a problem that is becoming more and more frequent.
Sometimes when I let the gas go and let the car slow down without breaking, the car starts jumping/coughing, but it goes all perfect again if I accelerate.
Never had any problem with idle either.
What is it?
HT leads?
Spark plugs?
Something else?

Thanks

 

[Mottie]

Wouldn’t think it would be the plugs or leads - they normally only play up when under load, I.e. accelerating. A common fault on Fords of that age is air leaks on the inlet manifold breather pipe but that normally gives you an erratic idle speed too. Worth checking out though. Looks like this:

 

[johnny2007]

Thanks, I'll check it tomorrow

 

[johnny2007]

@Mottie I couldn't find that pipe, but I checked all of the air pipes and they're not cracked or loose, in fact, they're quite soft for their age.
Was thinking of fuel filter, the only thing I didn't replace when I serviced it.
Looking at the service book, it was last changed in 2021, 7000 miles ago by Ford (God knows if they really did).
Could it be?

 

[Mottie]

@Mottie I couldn't find that pipe, but I checked all of the air pipes and they're not cracked or loose, in fact, they're quite soft for their age.
Was thinking of fuel filter, the only thing I didn't replace when I serviced it.
Looking at the service book, it was last changed in 2021, 7000 miles ago by Ford (God knows if they really did).
Could it be?

Your pipe may be slightly different. The hoses being soft is the problem. They usually collapse on themselves. Have a peek at this:

Again, the fuel filter being blocked would show as fuel starvation when fuel demand is high such as acceleration and not at idle.