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1996 1.25 Loosing power - streever
Hello,

I have a Ford Fiesta 1996 1.25 Ghia. When I bought it I had this problem that on high rev in 5th gear the car starts loosing the power. The revs, though, stay the same. It is the speed that is decreasing. It does that for a while and then goes back to normal. But it only happens on high rpm and only in 5th gear or, I should say, when driving around 70+ mph. I mean, if I would drive on high revs in 2nd or 3rd gear, this problem would not occur. Meanwhile, when coming off from the motorway, the car is very jerky on low speeds as well (that's after driving it on the motorway). After one minute drive on the low speed the car adjusts itself to normal -- no problems with hesitation to accelerate, etc.

I looked into this problem deeply and it was suggested in many threads that it is the AFM (mass air-flow meter). I changed that and the problem really went away for while. Well, at least it became more subtle. Now it's been two months since the replacement and I haven't driven the car for 3 weeks as I was on holiday. I am where I began -- the same problem, even though there is this new AFM. For testing purposes I decided to disconnect the AFM and continue my journey on the motorway. It was better, but the problem was there very, very, very subtly. I mean, it still felt like someone is pulling the car back but not nearly as much. So there is a connection with the AFM, but not only with it. Or the AFM is only the immediate cause while something is the real cause?

(The mechanic said everything is fine with spark plugs)

Thanks in advance for your help.