Misfiring Problem Mk4 1.3 Fiesta

[msajohnson94]

hi i have a mk4 1.3 fiesta with a misfiring on 2 and 3 changed the ht leads and wont start. i took of the rocker to try and get the first piston top dead centre but very last rocker and the last valve has a gap width of a little finger and the rockers are covered in grit and lumps of dirt.

[Zachayter]

Taken from my thread on this:

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I purchased a cheap throttle position sensor from eBay for £15 (genuine part normally costs £70), fitted it and didn't solve the problem, so moving on.

After some research this is what I have found with regards to the stuttering/fuel starvation/misfiring :::

ecutesting.com :::

This common fault of misfire on two cylinders or complete non start is often caused by the ignition coil pack shorting out on the vehicle - it is very important that the ignition coil pack is replaced at the same time as refitting your ECU after it has been repaired - or your faulty coil pack may damage the repaired ECU. - http://www.ecutestin...u_misfire_.html

EXCELLENT thread from RAC.co.uk on this topic :::

Lots of detail into this very common Focus MK1 98-04 fault here:

- http://www.rac.co.uk...Focus-Misfiring

How I think the problem occurred :::

I believe that when the speed sensor started malfunctioning I continued to drive the car, which may have caused the faulty speed sensor to damage the Ignition Coil Pack which then damaged the ECU.

How I'm going to tackle it now :::

Take out the ECU, read it's part number and send the ECU off for repair/replacement by ecutesting.com for (hopefully) £150.

Purchase new ignition coil pack for £25.

Will let you know how it goes :)

http://www.fordownersclub.com/forums/topic/44114-speedo-ecu-my-story/

[msajohnson94]

sorry but is the same as a mark 4 ford fiesta 1.3?

[Zachayter]

Just found this but then saw your Fiesta is 2000 year, I'd put my money on this being the problem though. Google and research your symptoms before shelling out though I would!

"Ford Fiesta 2002 – 2008 misfiring on two cylinders.

The 2 cylinder misfire is the most common fault caused by the engine ECU for the Fiesta 2002 - 2008, the fault is originally caused by a faulty ignition coil pack that spikes voltage back to the engine ECU and blows the ignition output circuits for 2 of the cylinders. We can test and rebuild your engine ECU to cure this problem." - http://www.ecutesting.com/ford/ford_fiesta_2002-2008_ecu_faults.html

[msajohnson94]

thanks for the advice im going buy a second hand coil pack and ecu see if i can get it running

[msajohnson94]

update of the fiesta. found out the rockers weren't actually sitting on the push rods right might be the cause of the misfiring but ive changed the leads anyway. also another question will a 1.6 distributor work on a 1.3 fiesta?

[msajohnson94]

update just tryed starting it up and its just turning over but trying to start. i managed to start it up but had to keep the revs up to keep running but i took my foot of and it cut out. any suggestions .

[msajohnson94]

update i am now selling it as i think the engine is shot

[wase16ll]

If rocker not sitting on valve, chances are its because it's dropped a valve seat, which was quite common on ohv engine.

It's a fairly cheap repair if you take the head off, send to engineer to recut and press New seat in, then just grind New valve and rebuild.

So worth doing a compression test before condemning the engine

[msajohnson94]

its alright im not spending any more money on it i need it gone as i just bought a ford granada scorpio 1988 v6 automatic