Hi Guys,

Been having this 'problem' for a long time now and as winter approaches again, the problem always gets worse and more irritating. I think a quick history first and then the symptoms.

Bought the car in Oct '05. It had 56K on the clock. Pretty good shape. During the first number of months I had some intermittent "stuttering" with the car dying on me occassionally. The engine management light came on and after a number of trips to the local mechanic determined that one of the injectors was faulty. I did quite a bit of research on these forums at the time I can tell you!

Around the same time I bought a new thermostat housing and temp switch, but nevver installed them. Why? - it seemed to me that the temp was always too low - less than a quarter of the gauge at any time. By that time, spring/summer '06 had started and the stuttering faded away.

Quick time travel to the present day. Long nights, cooler days. The stuttering engine again. The car has put on about 10K in the year.

Took the car in for a service, and had the thermostat and temp switch replaced (coolant drained) - for no other purpose than to see if this was a potential cause of the problem. Picked up the car and the following morning, same problem. Asked the mechanic about it and his impression is that it may be related to the fact that the HT leads have one lead which does not match the others - its like a normal lead without the extension piece to reach the plug. Have now ordered a new set of leads (again, after some searching here... still awating their arrival)

Ok, now to the symptoms.

Firstly I'd like to say that when the car is on the motorway travelling at a modest 55 - 65 it appears to run very nicely. There is heat from the radiator and all looks / feels good.

There has been however 1 or 2 occassions where I have slowed down to a junction / roundabout and the car has cut out completely Bit of a shocker that as the P/S also dies. Starts again without problem though.

Anyway, grab the keys on a morning and head out to the car (6:30am) Often when pulling away I get a shaking/stuttering motion in the car. Not so bad now having been serviced but stil there. Run along in 2nd and the car always feels starved of fuel. Slow down to a junction, staying in 2nd and you think the car is going to die. Come to a stop at a junction and the car sounds like a Subaru - which I know is not a good sign, unless someone has replaced my engine Pull away again, give it some juice and there's a significant delay, almost like a faulty 2nd stage of the old carburettors. Even when I feel that the car is totally warmed up it still feels kinda sluggish and although the roughness and judder on pulling away in first has subsided, I'm not getting that warm fuzzy feeling. In fact, whenever I'm in stop-start traffic I'm kinda waiting for it to die or for the engine management light to come on again

Now at the moment we're not in the worst of weathers yet - that's still coming in Feb/Mar, so any assistance and/or advice about this sort of problem would be much appreciated, so that I can potentially rectify it before we get to the early part of next year. If not, I'll be in again (LOL)

Any questions for clarification or otherwise, please feel free to fire away, and I'll do my best to answer them.

Thanks a lot.

M

If it sounds like a flat 4 subaru engine then am guessing you are dropping a cylinder. this is probably injector related as my father in laws 1.6 did this. Always make sure the plugs/leads are ok though.

Yes, I thought that might be the case... Yet, when I looked at the spark plugs that were extracted during the service they all looked fine - ie correct colour etc. I would have expected the dropped cylinder one to have been a bit "messy".

Gonna have to wait a week or so for the new leads though, so that I can rule the leads out as the potential cause. Shot in the dark really

this is very common on the 1.6. we have a few threads about it lately, as i always expect this time of year.

when an injector fails the plug will burn dry, meaning it will look a lot cleaner than the others. however, injector failure always causes the injection system fault light to illuminate so i dont think its that.

what rpm does it idle at when cold? and what rpm when warm? if its not 1200+ when cold and not 850 (+-50) when warm then on the 1.6 you should try replacing the air temp sensor (£2-3 @ scrapyard) and removing & cleaning the idle speed control valve with wd40 or petrol. they're the most likely culprits. the fact it cut out a couple of times coming to a stop also suggests this is the problem area.

Hi Jug,

Thanks for the technical info re: plugs etc.

To answer your questions:

Q: what rpm does it idle at when cold?
>> something around 800rpm I think ... certainly not 1200+ for sure!

Q: what rpm when warm?
>> probably the same as cold .. can't get a good reading on this from the dial.

TBH, I was kinda toying with some temp reading sensor over the past couple of days - for no other reason than the summer/winter cooling effect, but did not know if there was such a switch easily accessible on the car. Thanks again, I'll certainly try that as well.

As to the "removing & cleaning the idle speed control valve with wd40 or petrol". Just bought me some new wd40 the other day at B&Q. Question is, where is the idle speed control valve, how do I access it. A little "how-to" instruction would be most appreciated here Jug. I read the one you did for the fuel injector removal and replacement the other day. Something like that would be great (if you get the chance)

M

it has a warm idle when cold, strongly suggesting the air temp sensor is faulty or disconnected. this sensor is screwed into the inlet manifold. it is the one on the right when looking into engine bay, the one next to the idle speed control valve (closest to throttle body). its easy to replace, and i'm fairly sure it will solve your problem, although the idle speed control valve could also be the cause so clean that as well.

Thanks Jug - Will definately have a look at this tomorrow (during daylight) and post-back what I find out. With any luck this could be a simple exercise ....

M

Update:

Checked the wiring to the air temp sensor last night. Looked pretty decent, but I suppose it could still be faulty. Still need to look at the idle speed control valve though.

Checked the idle speed this morning when I hopped in. On start, settled at around 1300-1400 rpm but after a short while (maybe a minute) settled to about 900rpm. Difficult to really make this call accurately.

So maybe its more of a "sticky" idle speed control valve then?

M

well to be fair 1300-1400 is what i'd exepct to see, and a lot different to the first claim of 800. so it looks like your idle speed control valve and temp sensor are working ok.

so my next question, do you ever see the fuel injection system fault light illuminated on the dash? (especially when you accelerate hard)

it is worth removing the sparkplugs to compare all 4. if one looks different (less/more dirty, different colour crust etc) that would be a great indicator of what and where the problem is.

did you get the new HT leads yet? thats also something that should be done before we go any further because odd leads with unknown age need to be replaced no matter what. your local motorfactor will sell you a set for approx £15-20.

Also worth checking the lambda sensor, when mine was out, the car used to sound like a Subaru also and was choking all the time.
If it's never been changed probably by now it should be.

if it also struggles to start when hot then the lambda could definately be an issue. although a diagnostic check at fiat is probably a better way to spend the same money.

Hi Guys,

Got the new HT leads installed and it looks like that helped the problem a lot. Not getting the "3 cylinder" start on cold start up anymore. Engine feels much more consistent whilst idling cold at the lights. Can't believe that someone would not bother to replace the leads for some proper ones ... for the sake of £20. My guess is that the one without the "plastic extension" piece was being cooked by the engine over time and did not operate properly when cold as a result. Last year I also had a fuel injector replaced .. and have now wondered whether it was the same cylinder (total guess)

Still getting a bit of stuttering at pull away though. Will keep my eye on it this week and let you guys know what happens.

Jug - sorry about the 800 thing .. but that's what it falls down to pretty quickly after starting - probably within 2-3 minutes I guess (don't know if this is the norm either

TheCrow - lambda sensor ... what's that? where is it? can it be easily looked at?

Thanks again guys,

M

when you replace a fuel inejctor you should replace the sparkplugs and HT leads, because the cylinder which had a faulty injector will also have a fualty spark plug and lead if it was run for some time with the fault. i've seen the lead get copper oxide (green) inside when run with a faulty injector. this often confuses people into thinking their injector replacment was not successful.

on a cold morning it should take a few minutes to settle at 850rpm so that sounds about right.

the lambda sensor is on the exhaust behind the cat. the wiring connector for it is behind the black plastic casing at the back of the engine bay, in the middle. there are 2 knobs you uncrew to loosen the plastic cover, removing it you will see some connectors, the one with a white cable on one side is the lambda sensor. try disconnecting it to see if there is any difference, if there isnt it suggests the lambda is dead.

Interestingly enough Jug the spark plugs all looked A-Ok when I looked at them after the service a couple of weeks back. ... and given that I have not seen an injector light come on at the dash since its replacement I'm asssuming that the problem you have described was an extreme case of the one that I had (maybe?) [green copper oxide sounds really bad ]

Thanks for the info on the lambda sensor - will check this out at the weekend - when its warmer and theres more light

M

misty4u_sa said:

I'm asssuming that the problem you have described was an extreme case

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very extreme, by the time i got the car the previous owner had done more than a year's worth of driving with a faulty injector.

jug said:

very extreme, by the time i got the car the previous owner had done more than a year's worth of driving with a faulty injector.

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thats exactly how mine is bloke had run it for a year and a half had to put all 4 injectors in new leads plugs and a lambda sensor £300 later and running sweet as a nut