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Tin-top woes Fiesta Mk 6 1.3 Judder
bigbravedave - 2/2/16 at 10:43 PM

The Wifes fiesta 1.3 Duratech 8V (90k odd miles)has developed a judder and the engine warning lamp is on. It feels like it is running on 3 cylinders or in a rough "limp mode" but has a healthy spark on all 4.

I've disconnected each plug in turn and the engine note drops each time, so I think its firing on all 4. All the vacuum and breather hoses are in place

If you disconnect the crankshaft position sensor the engine stops.

However if you disconnect the crankshaft position sensor it doesn't appear to make any difference. so I'm guessing its that?

I work on industrial diesels for a living and they will run in "safe mode" on just the crank or cam position sensor and flags a code should one of them go down. However pn the fiestas dashboards diagnostic mode under the DTC menu it says "none"

I will see if I can borrow a fault code scanner tomorrow.

Any ideas in the mean time? thanks!


britishtrident - 3/2/16 at 12:05 AM

Disconnecting sensors tells nothing except the ECU's fall back strategies.


Without running a proper diagnostic scan you will be floundering, and because you have been disconnecting sensors any codes currently set will be invalid so it is case of clearing the codes and reading them when they reset.

Without a code scanner (one that reads live data) all I can sugest is try the Ford usual suspects by cleaning the EGR and IAC valves and checking for vacuum leaks and running a compression test. You could check the lambda sensor is switching hi-lo-hi, check the valve clearances.


jambojeef - 3/2/16 at 12:22 AM

Unplug each injector in turn - had this problem on a 1.3 Ka and it turned out to be a duff injector.

Never seen it on a car before or since!


bigbravedave - 3/2/16 at 12:00 PM

Fixed it, Although it turned out to be a combination of things,

number 2 spark plug was wetter than the rest, despite having a spark so I replaced the HT lead, which improved things to half as juddery, then I found a crack in the coilpack housing, swapped that and instantly no judders,

The engine warning lamp was still on so plugged into the OBD which pointed at the cam sensor, replaced that.

The lights gone out and the cars spot on. ta for your help


DW100 - 3/2/16 at 12:12 PM

Well done.

Was there a code for cam position sensor because you un-plugged it?


adithorp - 3/2/16 at 12:15 PM

quote:
Originally posted by DW100
Well done.

Was there a code for cam position sensor because you un-plugged it?


Beat me to it.


bigbravedave - 3/2/16 at 06:36 PM

cynics! I did clear active codes after the unplugging session, can sensor was the only one to rear its head. I was surprised how few codes did flag from unplugging things, maybe 14 years ago engines had to sense faults for longer before flagging codes. The modern stuff I work on goes into limp mode or idle lock within seconds of a sensor fault, I wonder if it's done for emmissions regs


mcerd1 - 3/2/16 at 11:06 PM

quote:
Originally posted by bigbravedave
cynics! I did clear active codes after the unplugging session, can sensor was the only one to rear its head. I was surprised how few codes did flag from unplugging things, maybe 14 years ago engines had to sense faults for longer before flagging codes. The modern stuff I work on goes into limp mode or idle lock within seconds of a sensor fault, I wonder if it's done for emmissions regs


^^ my focus (y reg) would flag it as a pending code for a while, then 'upgrade' it to stored one after a wee while...



btw I take it that this was the 60ps 1.3 Duratech 8V = aka the 'Endura E' the old iron blocked push rod lump ?
(same one as the original KA's, basically a Kent x-flow / Valencia development)