Fiesta Mk3

[Bill]

My son has an N-reg Fiesta Mk 3, 1.1 litre petrol, which is in good condition except that the engine can stop at any time or sometimes revs like mad to frighten old ladies at the traffic lights. It is now at the stage where we daren't drive it more than a few yards.

Our local friendly garage has changed a few bits but his next guess is the thing under the air cleaner - a single point injection unit, I'm told. I bought one off ebay, but when it arrived it was a carburettor, so I now have the money back.

I have rung round every local scrap yard to no avail.

It has been suggested by an American friend that in their cars, these things have a throttle position sensor, which is a small electrical potentiometer that is a likely failure point and can be measured with a multimeter.

I'm a bit crippled at the moment and really don't want to be looking at a rusty engine, so I thought maybe someone here might know how easy it is to check out this pot, or might know somewhere likely to have a complete injection unit lying around.

[Mike Tomlinson]

En el artículo , Bill escribió:

Please pass on my commiserations.

Post in uk.rec.cars.maintenance. What the regulars don't know in there isn't worth knowing.

[Chris Wilson]

Hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahhahahaha ...

Sorry couldn't resist myself :-)

[Andrew Gabriel]

Yes, indeed.

I had a P-reg Fiesta, possibly Mk 3, which started doing the same thing, at least the revving on idle occasionally, very slowly getting more frequent, but not stalling. I part-exchanged it.

[Bill]

Yebbut, the inside of his resembles an Amazonian rain forest, and it has a towbar that allows him to take tons and tons of stuff (ivy, old roof etc etc) to the tip in his trailer that they made him get a tip licence for.

We need to get it going, otherwise I am called upon. Last weekend I had to fold down the back seats in our car and do 3 trips on his behalf with the back full and his trailer fully laden. I'm still finding crawlies and slugs peeping round the tailgate. Besides, the Fiesta has no power steering, so can be towed home safely, and the paint has faded so much that he is happy to leave it in the station car park when he has to work away.

I'll look into the car maintenance group. Thanks.

** My other car anecdote is that last week I accosted 2 men standing gazing at a nearly new Astra parked outside next door. They had come 80-odd miles from Bangor to collect it only to discover it had a puncture, no spare wheel and the squirty goo had not worked. Several days later they returned for it with the transporter trailer.

[Jim K]

shurely a new tyre was indicated?

Jim K

[Ian Jackson]

In message , Andrew Gabriel writes

any help?

[Chris Wilson]

....

My apologies, I know my reply wasn't helpful but we had some at work years ago ... yuck. The car maintenance folks will probably start dribbling at the thought of a Mk3, granted I know beggar all about cars but I seem to remember that there's enough bits on those things to make them worthwhile jobs unlike the modern stugff which is dealer only for the folks who like to get grease under their fingernails.

[Bill]

In message , Ian Jackson writes

Afraid not. The lambda sensor has apparently been either checked out or changed. I've been pointed to a forum in the other ng and am working my way though all the suggestions, most of which have already been checked by our usually excellent local small garage. One problem is that I haven't yet sussed out whether this car has any sort of diagnostic port. There seems to be a bit of info on the net about a 1.4 cfi Fiesta, but very liile about the 1.1 version (which I think is a completely different engine..

The Haynes manual seems little help, the car is in my son's path, so I have to travel to look at it, and I recently fell on my chest and head and am still in the ache recovery process.

Anyway, I've got another single point injection unit coming from a scrappy, so we'll see what happens with that.

Failing everything, I'm probably going to try to push him towards an even older, simpler vehicle.

[Ian Jackson]

In message , Bill writes

There's no doubt about it, modern cars are increasingly becoming almost impossible for DIYers to diagnose faults on, and to fix them.

[Tim Lamb]

In message , Ian Jackson writes

Yes.

I suspect the fault that killed my daughter's Golf GTi is/was a dead NiCad cell pack in the factory fitted alarm system.

When the tuits arrive, I may get to prove this.

[Tim Watts]

They are becoming impossible for the dealer to diagnose too.

If the on board ECUs do not detect a recordable fault, that's pretty much game over.

Examples:

1) Daewoo Lanos would not start after being on a long run. Next day, it would start OK. Vauxhall (who owned Daewoo by then via GM) could not see why. I poured over the schematic, went on USENET and talked to an AA bloke. Afterwards, I concluded it was most likely (but not guaranteed) to be the crank poistion sensor failing with heat. I asked the local mechanic to change it at my risk and it was fine.

2) VW Touran PD diesel - if parked for 2-3 weeks, sometimes (twice to date) it will not start. First time it was towed and eventually they restarted it with EasyStart. No faults indicated. Second time, the AA bloke, after pulling the fuel lines off to check the pump, tried EasyStart. It worked.

VW, when I took it in for an MOT and asked them to see what's going on, had no idea. I conclude it may be because of drain back and air getting into the diesel system. AA bloke said if the diesel does not get upto pressure at the inlet to the diesel pump, the injectors will not fire. It is parked on a hill when this happened.

3) Sometimes the dash display (odometer and trip indicators) blanks and stays that way until a day or two later. VW: no idea...

4) VW Touran would not start - this time, no fault codes, by independent VW specialist eventually after 6 hours (he charged me for 3) found the air flap motor had jammed shut - this has no feedback so the ECU did not know.

The thing here is that there is now as much need for proper mechanics rather than the competant but not very imaginative fitters the dealers employ.

[Dave Plowman (News)]

I don't know that car's injection system, but all have some way of controlling the idle speed. In this case a stepper motor or solenoid opening a throttle bypass valve would be my guess. They are notorious for jamming due to carbon build up so my first check would be to remove it, clean, and check for correct operation.

On a petrol car of this age altering the amount of fuel injected won't cause it to 'race' without the corresponding amount of air being let in too. And that is controlled by a conventional throttle and the idle control valve. You could also check for any air leaks on the engine side of the throttle too.

[Dave Plowman (News)]

Only because they never had the skills to check the basics or more likely can't be bothered. The majority of such faults are sensor faults and each sensor can be checked using inexpensive equipment like a DVM.

Old fashioned methods would have worked there - as with much else. If the system relies on the crank position sensor only, there would have been no spark if it failed. (My BMW defaults to the cam position sensor if the crank one fails to give a limp home mode. But does store a fault code if either goes intermittent)

[Jules Richardson]

The van's an '08 and threw up a useless 'check engine' light a couple of days ago - which could be anything from simple emissions problem to impending doom - so it'll be off to my brother-in-law's at some point as he has all the kit to pull the fault codes and look them up; even if I had the necessary plug-in widget, the manufacturer doesn't publish the fault code data for mere mortals anyway. ffs.

[Dave Plowman (News)]

Most of the common faults are able to be read by a standard reader on all cars after a certain age. Of course there are others than can't.

[ARW]

Let me know the outcome. My brother is a VW trained mechanic (but on holiday until monday)

[Tim Lamb]

2 years and counting.... it was towed home by the AA and has gathered dust ever since.

Long way from Doncaster but perhaps you could drop him off as you go by on your way to London:-)

The immediate problem is initial charging of the replacement cell pack.

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