Hi guys,
I'd like to pick the brains of the Zetec experts here, if I may.
My daughter has just bought a P reg Fiesta, 51000 miles, genuine AFAICT.
When it's cold it's a real cow. It starts well and will idle OK but any amount of throttle will make it cut out and stall. It can be coaxed up the rev range but only very gently. It's like this for a few minutes then it's warmed up enough to behave better. It idles fairly fast (1500 rpm) for about 30 secs initially then slows down to about 900.
When hot it's much better but still not right. At ~4100 rpm in top it starts to misfire. If you're accelerating it's like somebody put the brakes on, it happens suddenly. Again, it can be coaxed further but only very slowly. It seems load dependant - if you're in a low gear it will rev past this point easily.
Another symptom is it's hanging on to revs when you change gear, about
3000 rpm.I have put in new HT leads and plugs (all Motorcraft) and cleaned the coil pack. I've cleaned the MAF sensor wires with carb cleaner and cleaned inside the idle control valve. The throttle position sensor is giving a continuous resistance change with no discontinuities. Nothing has helped. I don't know if it has an EGR valve. There's a vacuum pipe running down the bulkhead but I can't see where it's going. The air filter is clean but I suspect this is because the housing is only held together with one screw and therefore not closing properly! I did hold it together by hand but it didn't affect the problem. I was going to clean the throttle housing but it's got a sticker saying not to - there's a 'special coating' on the throttle plate for some reason.
I don't know what oil's in it, I understand the Zetec can be sensitive to oil type. It's getting changed tomorrow.
I would really like to read the error codes from the ECU (an EEC-V, according to the Haynes BOL). But I'm confused, since the vehicle (built in 1996, according to the VIN) has the 16-pin OBD connector in the passenger footwell but also a 6-pin connector with 5 wires and a red cap in the engine bay. It's labelled 'data link connector' on the Haynes wiring diagram.
Does anybody know which of the two is the pucker diagnostic connector? I suspect I'd just get some flash codes from the 6-pin connector, does anybody know better?
Any ideas and suggestions welcome!
Thanks in advance
John