General Random Cutting out

[egobirchy]

Hi - I wonder if anyone has any ideas about this... My Panda 4x4 FIRE 999c (1990) generally runs like a dream. One thing that is a bit iffy though is that it sometimes cuts out when slowing down for junctions. This generally happens when the engine is cold. I assumed at first it was just me mucking up the choke - and either having it too far in or too far out - but of late I've noticed that this happens even when the car is warmed up and the choke isn't being used. I notice the cutting out particularly happens at one section of road - coming to the end of a dual carriageway - downhill and slowing. By the time I reach the island at the end of the dual carriageway the car tends to have cut out. Clutch is usually depressed, so revs fall - seemingly too far.

Is it maybe just that the 'standing revs' or (tickover speed) need altering? - or perhaps something more complex and alternator related? any help appreciated. Thanks.

 

[pandafan]

My first two guesses would be that the tickover is too slow and that the mixture is too rich.
Do you have an in-line filter fitted? and, if so, when did you last clean or replace it ?
Regards,

 

[egobirchy]

Thanks Pandafan - nice to have 2 'do-able' things as suggestions. I'll try them at the weekend and let you know how it went. Thanks.
As for the filter - er, yes I think so. I'm a novice when it comes to car terminology. Its a standard fitting rectangular jobbie. Doesn't look too new. I'm planning on popping a K&N replacement on there as i'll be doing some driving at altitude - and that extra air might help!

 

[Giacosa]

I Would check the hot air intake off the exhaust manifold.(Corrugated foil tube) Even if it is not missing altogether an old cracked or badly fitting one definitely causes cutting out. Halfords sell a nice similiar thing that fits better than Fiats

 

[The Negotiator]

This regularly comes up in the uno forum if you're interested, it's usually solved by new distributor and vaccuum advance unit if it's the i.e engine. If it's just the cold, as mentioned, the tube helps.

 

[egobirchy]

@ Giacosa

Interesting. There is a very bizarre bit of corrugated piping that comes up from the manifold. It is seemingly a useless 3-4 inch piece of piping that just goes nowhere - it sticks out of the top surface of the manifold and just points upwards towards the underside of the bonnet. Is this the one you mean? If so - where should it be going?!?!

 

[phatbenny]

Yeah, that one's been puzzling me for a while, should it connect to something, and what is it for?

 

[The Negotiator]

It should connect from the top of the manifold to the bottom of the airbox, about 6" long if i remember correctly and a few inches wide.

There's should be a hole in the bottom of the airbox for it.

 

[John H]

Yeah, that one's been puzzling me for a while, should it connect to something, and what is it for?

Fitting as described by The Negotiator.

As I understand it:
the job of that pipe is to provide heated air (off the exhaust) into the air intake of the engine.

Inside the airbox there is a flap driven by a thermostatic valve.
When it's cold the flap lets this hot air in, instead of very cold air from outside.

Carburettors are prone to icing (cooling by evaporation), and the hot air stops that happening.

Symptoms of icing are usually grinding to a spluttering halt a few miles into a journey on a frosty morning. You wait a few minutes (the ice melts) and off you go for a few more miles.

During warmer conditions the flap lets ambient air into the carb, as the volumetric efficiency is greater with cooler air.

Injected cars are less prone to icing because the fuel supply is pulsed by the injector, rather than the continuous fine spray form a carb jet.
So I'm not too worried about the pipe being missing on mine.

If you have a K&N there will be no easy way of using this preheated air (other engine designs have manifold heaters).

 

[pandafan]

Hi,
Under normal circumstances I would ALWAYS recommend K&N filters, it's the first thing I ever fit, but.........I have no experience of really high altitudes.
I can see the possibility that it might cancel out your manifold pre-heating; but I don't know. Sorry.

 

[phatbenny]

egobirchy posting here - on phatbenny's computer!

Thanks again guys. I'm going to post a picture at the weekend, as i can't see where the other end of this corrugared pipe is meant to go. At them moment it just comes out of the manifold and points aimlesly upwards - but i can't see a logical destination.
Hopefully a pic or two will help solve this.
Thanks John H, Negotiator and Pandafan for the latest influx of knowledge.

With regards to the K&N situation - I'm thinking of installing this on the advice of a mate who runs a rally team and he's suggested that our 50bhp will likely be reduced to just 30bhp at altitude - thus the need for an aftermarket solution.
There is of course consideration to be given as to whether its a replacement panel filter (to fit into existing kit) or the full induction kit setup - the two will have different results.

As for the cold - it shouldn't be too much of an issue as we're travelling through hot countries in autumn - but obviously cutting out when tootling around now doesn't inspire the most confidence for a cross asia trip later!!

 

[Martiny10]

If it's happening when the car is warm - temp on the dial - I would replace the amplifier module on the distributor. It's the metal block with the fins on it, attached by a screw to the distributor body, on the side facing into the car.

At the very least, unscrew it, and check for corrosion in the socket.

The modules are expensive new, but a suitable replacement from an Uno, or other Panda, (possbily some Tipos and Lancia Delta's too) should be obtainable.

 

[egobirchy]

A big thanks to John H and the Negotiator. I've just had a real thrilling day doing various mods to the car including replacing the corrugated foil pipe which goes from the manifold to the air box. For info - I got hold of a 40mm diameter pipe and although its a touch too wide, its fits just fine since its essentially wedged in. I'll let you guys know if it stops the cutting out problem - but even if it doesn't it'll surely help the car run in the cold.

 

[Steven]

Just something about the little foil tube. My 1.1 Uno had one connecting from the bottom of the airbox to the top of the manifold. The 1.0 Panda doesn't. There is a hole at the bottom of the airbox, but no hole at the top of the manifold.

 

[John H]

Just something about the little foil tube. My 1.1 Uno had one connecting from the bottom of the airbox to the top of the manifold. The 1.0 Panda doesn't. There is a hole at the bottom of the airbox, but no hole at the top of the manifold.

The bracket on the manifold is pressed steel held on with the manifold studs, if the head's been off it probably wasn't replaced - in the same way that pipe gets left off with an air filter change.

Nearly all the time you won't know it's missing, but if you drive long distances in sub-zero conditions you'll soon learn about it.

 

[Steven]

So it's nothing to worry about then?

Actually, the last time it snowed here I got two streets away it the car stopped. It restarted after about half an hour. This is possibly why.

 

[Karmic_Nomad]

I have the same thing too.
It all started when a garage adjusted the tick over to get it through the MOT.
I have tried mucking about with hoses etc to no end. I had a coolant leak and for the week it was running hot it didn't shudder at all. But is annoying.
Especially when you brake down, push it off the road then the only helpful bloke in southend gives you a shove and you roll through the fence of the Weir pub and have to get the AA to free you.