General Running Problem

[nitro_warrior]

My Panda is suffering from a problem. (If i'm honest a few, but one at a time!)

The engine isn't running right, it almost is, but there's something up. Here are the symptoms.

• It is a bit reluctant to start from cold, but ok when hot.
• It seems to run well but after a while, once it's warmed up and the choke is in, it will keep loosing power.
• The power loss is usually brief but frequent and can go by changing the amount of accelerator applied.
• Pulling out the choke makes it run better.
• When it was very wet on Friday it lost power like above but it was a lot worse, I just managed to turn round and limp home.

To me it feels like the carb is icing (particularly as it was worse on a cold wet day). But the hot air pipe to the exhaust manifold is connected. Is a lean or rich mixture more or less likely to ice? Or does it make no odds?

Any ideas team?

 

[firstcar-Y10]

if it is icing, the pipe may be connected but is the thermostatic flappy bit in the airbox working (I'm assuming it's a FIRE engine) Every one I've ever had has failed one way or another and these days I just revert to a summer and winter setup on the airbox like I believe the older panda engines had, with the winter setting just permanently sucking hot from the manifold.
Anyway, aren't you supposed to be working?
Andrew

 

[sparkyfixit]

Sound like a few problems, as you said yourself! Common problems I've found with those symptoms have been: tiny splits in the spark plug lead ends letting the damp in and causing a misfire, and a bit of crap floating about in the idle jet in the carb causing a weak mixture. Not that it's the best solution, but the carb thing has been known to be solved by removing any jets you can get to, and firing compressed air through the jets and the drillings in the carb. Check the fuel filter too. Choke adjustments are notoriously poor on Panda's. That's always an adjustment I end up doing when I have a car in for service, even in the summer. Check that the idle mixture solenoid is working properly as well. It might have stuck half open, restricting the fuel flow to the idle jet. Splits in the leads can be solved with stretchy rubber sticky tape, or just replace them. Probably worth doing the dizzy cap while you're there.

 

[purple haze]

Check the previous threads....nito has done most of that already!!!!!

cheers kev

 

[nitro_warrior]

Check the previous threads....nito has done most of that already!!!!!

cheers kev

Indeed, but it's worth saying again! There's some of it that I should double check.

if it is icing, the pipe may be connected but is the thermostatic flappy bit in the airbox working.
Anyway, aren't you supposed to be working?
Andrew

That's something worth checking, I used to not have hot air pipe and the only time it ever iced was when it was snowing. But I have changed a bit of stuff since then.
And yes I am supposed to be working... speaking of which...

Thanks so far, keep the ideas coming!

 

[nitro_warrior]

Well I fitted a different air box with the hot/cold air flap set to draw hot air and went for a drive and it was still doing it. Possibly a little better, but really hard to say.

It doesn't do it all the time and when it doesn't it runs really well. It's particularly bad at lower speeds almost seems like a flat spot in the rev range when it happens. For example from stationary it will be idling ok but when you try to pull away it will almost die, give it loads of throttle, it will pick up and you'll wheel spin off the line.

What are the symptoms of a tempermental fuel pump? I've not heard of people having fuel pump problems on Pandas.

 

[Uno driver]

Check spark plug wires, as I had exactly the same problems. It lost power / died when I tried to pull away with normal rev-s. One wire had crack in insulation

 

[Bougainvillea Rosso]

Apologies if you've tried this already and mentioned it elsewhere, but as the above poster says, have you checked the jets on the carb? I've had muck in a jet before that made it run like a pig and ultimately stall. This might suggest why it is running OK when the choke is out? Doesn't actually sound like a fuel pump to me as accelerating shouldn't make any difference at the moment when the pump is not working.

Yes, could also be HT leads arching.

 

[Most Easterly Pandas]

Yes, could also be HT leads arching.

Yes, been there done that, and the car seems to turn into a right pig

 

[nitro_warrior]

Ok thanks guys, tomorrow i'm going to clean the carb a bit more thoroughly, and i'll change the leads, though they're not that old. I'll let you know what happens.

 

[nitro_warrior]

I'm struggling with this now! I stripped the carb and cleaned it thoroughly, blasting the air compresser at everything. I cleaned the contacts in the dizzy cap and increased the mixture a little. It runs better now, obviously I did all those things at the same time so it's hard to say what made difference

But it's still not right.

The main thing is it's a pig to start when cold, and pretty easy when hot. (Also, the ticker over wanders a little when idling.)
Jump leads from another car doesn't really help it start any easier, which to me suggests it's not electrical as a jump normaly overcomes duff leads etc.

I also checked the solenoid and could here it clicking when I plugged and un plugged it with the ignition on. I also took it out and it seemed ok, allthough how enthusiastically should they trigger? It seemed to need a 'tap' inconjunction with 12V to make it move, but like I say I could hear it clicking when conneted and disconnected whilst fitted to the carb.

 

[Chas Uno]

At a guess, poor starting when cold and easy starting when hot could be one of two things:

1. Your carburettor choke mechanism/ flap isn't operating correctly.

2. You have an over-rich mixture.

No.1 is easy to check. With the choke off, remove the airbox and look at the carburettor venturi. It should be open. Now pull the choke lever from within the car and go back and look at the carburettor. The choke flap should almost fully close the venturi. Pushing the choke off from within the car should open the choke flap again.

No. 2 - could be a flooding carburettor? Float height incorrect? An over-rich fuel mixture can inhibit starting and cause poor tickover. Do you get a smell of petrol out of the exhaust with the engine running?

A wandering tickover sounds more like an air leak. Check the carburettor to vacuum solenoid pipe - is it secure or leaking? Also check the small pipe that goes from the back of the airbox to the carburettor base. These are normally in poor condition.

The solenoid will have no effect on starting. It only affects the idle circuit, therefore if it has failed shut the engine will stall unless given throttle. They either work or they don't so I doubt if it has anything to do with your problems.

Hope you get it sorted

 

[purple haze]

Just fitted the idle solenoid kindly sent to me by Chas. (cheers mate)
Alot lot lot better.....but.....still having a problem with getting a smooth idle????? It seems to be hunting a bit. Starts ok..drives ok....

Sorry Nitro, im not trying to hijack your thread, it just seems our problems maybe similar although mine starts fine??????

Cleaned the carb (It was fine!!) Timing ok.

What i need to know....Should the mixture screw be flat or very pointed at the end??????
Cheers Kev

 

[Alan.D]

It should be very pointed, and is a common problem, as soon as it's overtightened it goes flat and the mixture then suffers with the only option to change the screw.

 

[Most Easterly Pandas]

Just fitted the idle solenoid kindly sent to me by Chas. (cheers mate)
Alot lot lot better.....but.....still having a problem with getting a smooth idle????? It seems to be hunting a bit. Starts ok..drives ok....

Sorry Nitro, im not trying to hijack your thread, it just seems our problems maybe similar although mine starts fine??????

Cleaned the carb (It was fine!!) Timing ok.

What i need to know....Should the mixture screw be flat or very pointed at the end??????
Cheers Kev

Is this in the Sisley Kev

 

[purple haze]

Yes mate the sisley.......Cheers Alan, thought it should be pointed.

Mines FLAT!!!!!!!!!!!!!!!! Is this part available from Fiat???????

If not......Chas....HELPPPPPPPPPPPPPPPPPPP.


kev

 

[nitro_warrior]

Sounds like something I should look at too. ANyone got pictures of what it should look like?

I've also picked up a new dizzy cap and rotor at lunch, will see how that goes.

 

[Alan.D]

Yes mate the sisley.......Cheers Alan, thought it should be pointed.

Mines FLAT!!!!!!!!!!!!!!!! Is this part available from Fiat???????

If not......Chas....HELPPPPPPPPPPPPPPPPPPP.


kev

Not sure mate but don't think so. I managed to find a brand new carb on ebay so had that resolved.

 

[purple haze]

There was a carb on ebay last week!!!

Knew i should have got it...(£9.99)

Nitro.. its easy to spot/check...take it out (you will have to pull it at the end after unscrewing as there is a rubber "o" ring) you will see it is flat or if pointed you can prick your finger with it.

Having seen others i thought mine was knackerd!!!!


kev

 

[nitro_warrior]

Well I replaced the dizzy cap and rotor and it made no difference. *sigh*

So I pulled out the mixture screw, not sure if mine is "pointy" or "flat" you would struggle to prick your finger, I suspect it's flat. The flat bit has a diameter of 1mm. I took the screw from my spare carb and it looks the same. See the pictures below, current screw on left spare on right.

and one with my fore finger for scale