I have a 1988 Ford Fiesta 1.4 CFI as a cheap extra car. The car is in
an excellent condition, but when accelerating at low speeds it
hesitates. When it reaches about 3.000 rpms it accelerates without any
I have renewed the following (low cost) components :
- Spark plugs (Bosch FR 7 DCX+) gap set to 1.0 mm according to Haynes
- HT-leads replaced
- Distributor cap replaced
- Air filter replaced
I have asked at the local Ford dealer about the cause. Here it was
suggested that it might be a vacuum leak, getting "fake" air to enter
the inlet after the injection unit and thereby screwing up the
mixture. This explanation sounded quite reasonable, but after
inspection I have not been able to locate any leaks. I have also used
some "start-spray" to see if the engine would increase it's revs when
it sucked it in (this was recommended by the Ford dealer).
I think the reason might be incorrectly set gap on the spark plugs
since it seemed like the problem got better when I changed the gap
size from 1.1 to 1.0 mm. But I can't see why this should have any
influence at low revs - I would expect it to be a problem at high revs
if the gap was set incorrectly.
Another thought that crossed my mind is the capacitor for the ignition
system. Can it be broken and would it result in a symptom like the one
Any help would be highly appreciated.