General Uno 1.0ie - cutting out when hot

[trublue]

Hi guys, I'm new to this forum.

This question has probably been asked many, many times before (apologies) but what are the most likely causes of a 93 (L plate) 1.0ie Uno idling erratically and cutting out when hot?

The engine runs fine until it's been going for half an hour or so, then when pulling up at lights the idling rate increases, then drops before dying altogether. It can be restarted after waiting a couple of minutes, then may or may not happen again. It's usually OK if it can be kept moving/revved when stationary.

I am probably going to try changing the distributor first as it reminds me of a problem I had with an older Uno where it would not start at all unless cool. Also, reading some other posts on the forum would suggest this is quite a common cause of trouble.

However, with this being a more recent model, is it more likely to be the engine management system - lambda/airflow sensors? I am reluctant to spend money on diagnostics at a main dealer as it ain't cheap!

Any advice gratefully received.

Cheers

 

[The Negotiator]

Distributor and vacuum advance unit replacement nearly always cures this problem IME (I had the same on the same car, just an M-reg) vacuum advance was the problem - exactly the same symptons as on yours.

Also clean out throttle body (undo all connections to black air box and updo nut on the middle at the top) Lift up and that's the throttle body, if it's dirty, clean it the best you can, make sure nothing goes inside down the hole - clog up with rag but make sure you can remove it!)

I played around for weeks with throttle control aswell - aslong as the butterfly valve opens and closes it should be fine, check stepper motor aswell.

But again, I can give you a 95% assurance that it will be the vacuum advance and distributor.

Let me know if it's sorted...

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Uno 1.0ie Start. Standard.

 

[trublue]

Thanks for the tip - 95% sounds quite hopeful! Will certainly try that...

Any tips on fitting the new distributor and correctly adjusting it? Don't have a timing strobe or anything like that. I have changed one before, under supervision, but my memory seems to have failed me! I know you have to make a mark somewhere :I

 

[The Negotiator]

There's a guy called Dave who will be a lot better equipped to help you with such a question. My grandfather helps me do the work and I just know what we did to solve it and have advised this before and it has worked before for at least one other person (hence 95% ) on here. Dave knows what he's talking about with mechanics....Give him a few hours, he is bound to see this and answer your reply

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Uno 1.0ie Start. Standard.

 

[The Negotiator]

Just wondering if you sorted this problem out by any chance?

Regards
Paul

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Uno 1.0ie Start. Standard.

 

[trublue]

Hi mate, thanks for the tip. Fitted a new (well, reconditioned) distributor yesterday. And it has solved the cutting out problem.

HOWEVER, it does not start as easily now and has lost power. It was quite nippy before, now it feels really laboured. I'm just wondering whether the timing has changed. I'm pretty sure it can't be more than a couple of mm out with respect to where the old one was positioned as I marked it up. Am going to try tweaking it tonight.

If I have no joy there, I am thinking I might put the old one back on, replacing the vacuum advance and the ECU module. Any probs that you know of with doing that? As far as I know all the components are interchangeable.

 

[The Negotiator]

Again, I know so little. I shouldn't think the ECU being changed would be a problem because there's no immoboliser but in all honestly, I don't think it would be this. We went to change mine (we have a spare Uno) but decided it was working enough to run it so it must be something mechanical playing up. We then changed the throttle body - very very little improvement, just a coincidence most probably - and it was the vac advance that actually fixed it (although I think we did the distributor before this time but can't be exactly sure). I'm surprised Dave hasn't come to reply to you about timing etc. if he doesn't today I will drop him a PM to offer you some advice on it.

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Uno 1.0ie Start. Standard.

 

[trublue]

Appreciated.

Thing is, on the earlier model Uno I had, changing the ECU worked for a while - however the problem cropped up again and the whole thing had to be changed over.

 

[dave]

I would have thought that if you fit new distributor, it is best to check timing with a strobe, are the contacts in side the cap ok some times if they are worn they work ok untill you disturb them, but then stat playing up.

----------------------------------------------------------------------------------
Please do not Email or PM me asking for support. Post on the forums instead. Your reply may help someone else. Thank you

 

[trublue]

Haven't got a strobe to check timing - I tried rotating it a couple of mm in each direction but it didn't make much difference.

I am starting to think I have been sold a duff part as I put the old one back on with no problems and it started up first time and the acceleration power was back (but so was the original cutting out problem!).

Was thinking about stripping the old one down and replacing individual parts (vac advance/ECU) but I don't think it's worth the hassle. Think I will ask for a replacement from the place I bought it.

As for the cap - yes the contacts do look a bit worn - will buy a new one I think.

Cheers

 

[Martiny10]

Hi there,

I am assuming this is the 999CC FIRE i.e. (I don't own an Uno)

I had this problem on my Y10 - the solution was to replace the amplifier module on the distributor- it's a little black box with metal fins on it and is held on by a screw. So you could take the module off the 'new' distributor and attach it to the old one.

However I suspect the real problem is that the timing is out. Pull the little rubber bung off the gearbox (below the distributor) and line up the timing mark on the fly wheel with the 0 degree mark on the gearbox housing. You do this by jacking up one wheel, selecting 4th and then rotating the wheel until the marks line up - and assisstant makes this easier.

When this is done, pull the cap off the distributor and line up the rotor arm with a mark on the distributor body. (It looks like a snmall triangular notch.) Line up the marks by unbolting the distributor and rotating it.

Finally tighten up, put back together, stick the rubber bung back in and take for a spin.While not as accurate as a strobe, it is close enough. The car may idle badly for a while until the ECU 'relearns.' A good drive or fast idle for 10mins should sort it out.

Hope that helps.

Regards,

Martin

Fix It Again Tony!
Would swap for X19, Montecarlo Spider or GT.i.e in average/poor condition! Scottish based would be nice.

 

[trublue]

It is indeed a 999cc Fire engine. I have now bought another distributor complete with cap, amplifier module and vac advance. Fitted it this morning and had my first trouble-free trip of more than half an hour!

So, fingers crossed, that was the cause of the problem. Thanks pghstochaj - your advice gave me the confidence to change the part and from speaking to people and reading the posts on here it is a common fault on Unos - thankfully it is not too difficult to fix. Hope this helps anyone with a similar problem.

Martin - you may well be right about the timing, it is not running as smoothly as I would like and I think I will adjust it as you suggested. I assume it is the driver's side front wheel you have to jack up is it?.

Cheers all!

 

[Martiny10]

Yeah, drivers side is best.

Fix It Again Tony!
Would swap for X19, Montecarlo Spider or GT.i.e in average/poor condition! Scottish based would be nice.

 

[Morty Mort]

Depends on what size is the driver's side? Heh .


gas lowered on abarth wheels. upgraded interior and visuals. audio through phoenix gold and BLOWN kenwood.

projects: air in and out.

Honey that ain't no pistol - that's my LOVE GUN.

 

[Martiny10]

Since the car is in the UK it's a safe bet to say that it is RHD.

Fix It Again Tony!
Would swap for X19, Montecarlo Spider or GT.i.e in average/poor condition! Scottish based would be nice.

 

[trublue]

As a footnote...

Thought the problem had been solved, however after about a week, it started to play up again. Would cut out when idling with no warning, and wouldn't restart for a few minutes. Very embarrassing when you're stuck at the lights with a queue of traffic behind you!

However, I didn't panic as I was fairly certain it was the amplifier module. Had a spare which I fitted - problem solved (touch wood!).

Tried lining up the timing marks - I did everything suggested by Martin (procedure also covered in the manual) but it seemed to make things worse - acceleration became very sluggish. Luckily I had marked where the original distributor had been fitted so used this as a guide instead and the power returned.

Looking back at this now - I think the most likely explanation is that the original idling problem was caused by the vacuum advance and the more recent problem by the amplifier module. I would advise anyone changing only the vacuum advance to be VERY careful though as it involves stripping down and rebuilding the distributor and if you don't do it correctly it may be badly damaged when you start the engine [xx(] probably easiest to change the whole thing if unsure.

This has taken longer to solve than I anticipated but hopefully it's sorted now and I've learned a fair bit about my car along the way. So it's not all bad.

 

[Chas Uno]

Trublue, I suggest getting the timing checked/ adjusted by strobe to eliminate that from the rough running problem. If the engine doesn't rev as freely or feels sluggish it sounds to me that the timing is out. Also bear in mind that if the timing is too far out it can cause pre-detonation (pinking) that can eventually lead to burnt valves and holed pistons.......

Also worth fitting a new distributor cap and rotor arm, they're not expensive and do wear out over time.

It is also quite easy to change the vacuum advance unit without dismantelling or removing the distibutor. Remove cap and rotor arm, remove two screws holding the vacuum unit, use a blunt screwdriver and push down on the plastic arm of the vacuum unit (you can see it through the top plate of the distributor). It should just pop off.

Fitting a new advance unit is a reverse of this, though it needs a little bit of fiddling to pop the plastic arm onto the lug under the top plate of the advance unit.

To line up the timing marks you can also do it without jacking the car up. Have the car on a FLAT road/ driveway, put it in third gear and release the handbrake. While looking at the timing marks through the gearbox inspection hole simply push the car back or forwards until the marks line up. Saves having to jack the car up!

Your initial problem of stalling and eratic idling sounds so familiar to everyone who's suffered a failed vacuum unit. You might have found simply replacing that without touching anything else would have solved the problem!

Hope you managed to get it all sorted now anyway.

 

[trublue]

yeah thanks mate, got it all sorted now. It's running well and there are no more idling/cutting out problems. I could probably have made life easier for myself if I'd known a bit more about it but there you go.

 

[Chas Uno]

Did you find out what was causing the main problem? Was it the vacuum unit or the distributor/ ecu?