my car is misfiring

woodyracing · 12 Mar 2003, 02:09 (Ref:533434)

car is Ford Fiesta XR2i 1800cc Zetec,
ive changed spark plugs and HT leads and no luck.

Can anyone think of anything else it could be?
There's also a funny clicking noise near the fuses and relays. And there doesn't seem to be any problems with the fuel lines, and the fuel filter is new enough.

Bluebottle · 12 Mar 2003, 22:41 (Ref:534401)

Is it constant or just at certain times i.e. acceleration, high revs etc? If it was one of my cars I'd be also looking at the distributer cap, points, rotor arm (anyone old enough to remember those

) so it's probably worth checking the ignition module thingy....er, I'm lost now!

**touringlegend** · 12 Mar 2003, 22:43 (Ref:534403)

Or even worse, something inside the engines went wrong? Here's hoping not.

Se7en · 12 Mar 2003, 22:49 (Ref:534409)

What year is your car Woody? Do you know which cylinder is misfiring?

Your local Ford dealer should be able to scan your XR2's ECU to determine the fault. This may sound expensive at first, but could still be a lot cheaper than replacing a lot of parts that aren't faulty. It could be one of your coils, a sticking valve, (quite common on early Zetec 1800's) a burnt exhaust valve, an air leak at the inlet manifold, a faulty diaphragm in your servo which would cause an air leak and hence a weak mixture in the cylinder closest to the vacuum take off port, a faulty throttle position sensor, EGR valve, MAP sensor, knock sensor, Cam position sensor, crank position sensor, coolant temperature sensor... You get the point!

By the time you've substituted any or all of those parts, you'd easily be looking at the price of a scan. I bet you didn't get much change out of £35.00 for your ignition bits, did you? Go on! You know it makes sense.

woodyracing · 13 Mar 2003, 10:07 (Ref:534860)

so many faults it could be !

its misfiring throughout the rev range and sometimes cant even hold itself at idle, and then it stalls. It has electronic ignition, so non of them old type distributor things. Not sure which cylinder it is.

It also seems a bit intermittent, because the other day it was fine in the morning and then went again in the evening. Also I think it was a fluke that it started working while the AA guy was there. He checked the sparks on each cylinder and it seemed fine but it was still misfiring then eventually it started working. Apparently, spark plugs are often to blame for this so the AA guy fitted some used ones which he had in the van but that didnt make any difference. I fitted my old HT leads when i got home as I knew these work ok, but that didnt make a difference either :|

Im going to ask at Ford next and try to get it there, so far its not cost me anything but its always shocking when Ford give me a quote.

Barry Pomfret · 13 Mar 2003, 18:54 (Ref:535291)

I have run Zetec engines for several years in Formula Ford. Most of the sensors are pretty reliable, the weak point is the coil/ ignition pack, these tend to cause a missfire if they have been over heated due to the ignition being left on without the engine running. We chased this problem for a long time a few years ago,I suggest you buy a new one, they are not cheap( about £60) but I think this could be your problem solved.

woodyracing · 13 Mar 2003, 22:35 (Ref:535498)

thanks, someone else mentioned the coil too.
Ford have the car now, so hopefully its just something like that, but still

anyone wanna buy a car?

its nice really!

Airhead · 14 Mar 2003, 11:02 (Ref:535907)

Oh Oh

Changed the leads and the plugs?

That's me out.

Time to trade up baby.

ss_collins · 14 Mar 2003, 11:56 (Ref:535945)

Theres an easy way to work out which cylinder is missing, whip the plucgs out nothing which was from which one, have a look at them a bingo you know where the mis is.

Airhead · 14 Mar 2003, 12:42 (Ref:535990)

Great and brilliantly inspired description of what the F to do.

Are you suggesting a plug chop?

woodyracing · 14 Mar 2003, 12:47 (Ref:535995)

The road side repair mechanic (AA) had a play with pulling out the spark plugs while the engine was running (to my horror

). He also let the spark, arc with the chassis and he claimed the arc was 28,000 volts which i find hard to believe - anyone know any better ?

Se7en · 14 Mar 2003, 22:38 (Ref:536477)

28000 volts is about right. Even that number of volts won't kill you as the current is so low. It WILL give you a nasty muscle spasm in the armpit though!!

The way to determine the cylinder that's misfiring is to pull each plug lead off in turn and note which lead has LEAST effect on the idle speed. Obviously the cylinder that's already missing won't be affected by a plug lead being removed. Make sense?

Glad it's met it's maker (so to speak!) *Groan*

ss_collins · 15 Mar 2003, 00:11 (Ref:536541)

Voltage is unlikeley to kill you, current is what fries ya.

woodyracing · 15 Mar 2003, 01:28 (Ref:536581)

I have the car back now and its fine. but thats the problem - its not been misfiring while Ford had it. So im no nearer fixing it but it does seem to be ok at the moment :S

Se7en · 15 Mar 2003, 02:11 (Ref:536593)

Did they scan it for you? Most OBD (On board diagnostic) systems have a fault code history. What did they actually say they did? Just ran it round the block no doubt!

I can't believe they couldn't find a trouble code that would lead to the cause of the misfire! What year is your car Woody?

woodyracing · 15 Mar 2003, 02:24 (Ref:536597)

its a 1994 L-plate

i give it to Rapid Fit instead of formally booking it in with Ford. They run the services differently. Like u said they just drove around in it at different times and it was fine. It didnt cost me anything either, but if I book it in formally I can get computer diagnostics and things like that.
thanks,

Smokey 6 litre · 2 Apr 2003, 13:52 (Ref:555947)

kick it till it works.

woodyracing · 2 Apr 2003, 14:02 (Ref:555959)

its fine now <shrugs> I changed the leads and give it some new platinum NGK plugs.