Eac Fail - 6 Week Problem......and Counting

[tired_boy]

I have a 04 plate, 1.4 tdci Fiesta Zetec. 40 days ago i was cruising along and felt a brief loss of power a few times. Over the next few miles heading home it got worse, was flashing EAC FAIL on the dash and i struggled to get the speed up on the 60mph A road.

I limped into the village garage who changed the fuel filter - no joy. I took it into town to get it on to a machine to observe live data. They told me they were getting low pressure from the pump and that it needed replacing - perhaps the injectors too. So, i got a 2nd hand pump, had it fitted elsewhere, new timing belt, new starter motor as that packed up too - no joy, exact same problem (having thought it had been resolved though, the mechanic took it in for its MOT which it sailed through). It then went to another garage to be put on the machine. He then said air flow meter was coming up and throttle position sensor was worth looking at. So, its had a new pedal because that has sensors in it, and its had another air flow meter (MAF Sensor) - no joy, excatly the same! I've disconnected several connections and used contact cleaner - no joy. The mechanic is now scratching his head. All of this has taken over 6 weeks.

It starts up first time no bother at all. The revs are fine when idling, no jumping around, nothing erratic with the revs. There is no pattern to it losing the power, it just does it when i try to accelerate too quickly. It then flashes EAC FAIL on the dash, i come off the power and it stops flashing it, and i could then accelerate IF i do it gingerly - anything heavy footed and there's no power and its off flashing the dreaded words at me again. It NEVER cuts out requiring restarting. The engine management light does not come on at all.

[tired_boy]

Well, i changed that pedal as i said, took it for a run. no joy. The next day i changed the air flow meter and took it for a run, no joy. The next day i changed the air filter (becuase it just needed it anyway). Took it into the garage to go on the machine again and it was just the same as its ever been. He then left it on the machine all night and said it wasnt come up with anything. He then took it on a run and it was absolutely fine. I have just driven 20 miles home and its been absolutely fine. Nobody did anything. It could just come back the next time i go out and we could be back to square one but at the moment its back to normal. Some have said that it can take time for the ECU to 're-learn' anything new put onto it. Is there any truth in that at all? Maybe the parts i replaced did the job and it took the ECU a day or two, or a few miles to 'get with the program'. That doesnt make any sense to me personally but........

[stubwfc]

Have you not tried cleaning the throttle body?