Hi everyone

After years of good service and a long run last weekend my cinq decided to start friring on only 3 cylinders .. I removed the plugs and low and behold pretty crapped up so I replaced with new ones cleaned airfilter and had a quick look around .. result ?
Its still firining on 3 cylinders .. the left hand one is simply not firing..(looking from the front of the veh) although there is a healthy spark there .. anyone had this before or can shed some light on the problem ?
I am at present out of work an a garage is simply not in the frame..

In order for a cylinder to fire you need fuel (you've got that), a spark (you've got that) and compression. Get a compression test done.

Chances are that at least one valve in the cylinder which isn't firing isn't closing.

fingers99 said:

In order for a cylinder to fire you need fuel (you've got that), a spark (you've got that) and compression. Get a compression test done.

Chances are that at least one valve in the cylinder which isn't firing isn't closing.

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thanks for the quick reply .. I dont think its comp ..

I will borrow a comp tester tmrw and give it a go, If it is comp how difficult is it to set up the valves correctly ? Is there an online maual fo rthe car anywhere that anyone knows of ?

It shouldn't be that difficult -- after all, it's a simple OHV engine. You could even pick up a spare head from a scrappy.

No on line manual, but most Halfords have the Haynes Cinq manual in stock. Rallycinq on here knows those engines back to front and upside down, in blizzards, floods and force 10 gales.

Someone call?

Pop the rocker cover off and turn the engine by hand, you'll soon see if anything is amiss. It is clockwork simple.

Do you have any popping back from the TB?

Cheers

D

OK had a quick look with the cover off .. it looks OK cant see anything out of the ordinary.. ie no water or anything to suggest a knackered head gasket and no strange noises at all .. runs quite sweet really just that one cylinder.... if I pull the plug lead off the motor carries on as before. take one of the other leads off and it starts to cut out..
I think I am going to have to wait to do the compression test tmrw eve. This is not the original motor a frioend of mine gave it to me and put it in, after I lent the car to a family member who ran it hard for a week without checking the oil and knackered it ..
This motor has only done around 35,000 miles and I have done the last 15,000 on it myself.
Oil changes and everything else I do myself regulary, but motor stripping is not my " forte " .. Is this a typical fiat problem ? does it happen a lot ?

It only happens when they are roasted.

Just to recap, You have cahnged the plug with a known good one, and changed the lead with a known good one, the coil must be working, have you tried it at night, just to make sure the lead's not shorting?

Looks like head off time to investigate.

Cheers

D

Yup all pugs changed with new ones. the old ones had some buildup of black deposits on them.. leads I checked through and as there is a healthy spark at the plug I assume they are ok .. I checked last eve in the dark and could see no short of HT anywhere.. must get a better insulated pair of long nosed pliers ...
Somthing that came to mind ....a few weeks ago as I was driving up a long hill I suddenly lost power for a few secs as if the motor had died. I had forgotten about it as once over the hill she was running again ok, and has since then done a couple of simular trips without problems. I simply assumed a tempory fuel blockage or somthing, as I said she ran OK after that and even when I went on a long run she was OK fuel consumption was good as well....210 miles and used 20 liters but after that this problem arised. .. No its was not motorway at high speed either.
A friend is bring a comp tester round later this avo Once I get the readings I will know more .. anyone know what they are supposed to be ? and how much of a difference they can have ?

I really doesn't matter what they should be as the tester will pump up. You need to watch the reading as it comes up on the 'dead' one to see if it flutters indicating a leakage.

You need them close to each other.

Cheers

D

Thanks for the quick reply .. I know the ar is old and looks a wreck but she runs OK normaly and is fairly mechanicly sound underneath means less likey to get nocked lol . seems a good idea nowadays to keep a cheap car runing as long as possible rather than havng a fortune sitting on the drive doing nothing .. and paying the bank for the privilege of it .!

forcedfiat said:

Thanks for the quick reply .. I know the ar is old and looks a wreck but she runs OK normaly and is fairly mechanicly sound underneath means less likey to get nocked lol . seems a good idea nowadays to keep a cheap car runing as long as possible rather than havng a fortune sitting on the drive doing nothing .. and paying the bank for the privilege of it .!

Click to expand...

Absolutely agree, says he who is waiting for his new 500 to be built.

Cheers

D

OK comp check done .. left hand cylinder is only at 1/4 the pressure of the other 3 ..

Where do I go now ?

forcedfiat said:

OK comp check done .. left hand cylinder is only at 1/4 the pressure of the other 3 ..

Where do I go now ?

Click to expand...

A teaspoonful of engine oil down the bore and do the test on that cylinder again. Note any difference.

Cheers

D

rallycinq said:

A teaspoonful of engine oil down the bore and do the test on that cylinder again. Note any difference.

Cheers

D

Click to expand...

Chap with the tester is not going to show up. So I am going to take the head off in the morning ..

tips ?

Mod please remove this posting .. cheers

I meant to say the fella with the tester is not going to come back with the thing as he lives 30 miles away and he had only borrowed it himself to do the test for me ..

So head's comming off in the morning and then I will photograph each step .. it should help me remember where everything came from and poss help another member here in future ..
thanks for all the help so far..

Remember to drain the water system first.

Its easier to undo the exhaust at the down pipe flange and lift the manifold off with the head. You've already got the inlet off so next up is the rocker shaft. Undo the rocker shaft nuts then get a roll of masking tape and wrap each hydraulic tappet before lifting the rocker shaft. This stops bits of tappet scurrying down the drain.

Next up, the head bolts, really no need to undo them in a particular order, its a cast head.

There are no dowels so dunt the head with a rubber mallet and off she comes.

Cheers

D

can i just say, it is possible to take the head off without undoing all the pipes going into the TB, but how, you'll need to ask Rallycinq, was just magic

OK .. everything in pieces and it seems a valve has broken .. left hand one in the picture attached has a small piece missing .. The other 3 pots look pretty crap as well.
So
1 I need to replace that valve .. which one is it exhaust or inlet ?
2.Do I need to replace any others ?
3 can anyone diagnose from the sate of the head and block what is causing the deposites on the other cylinders ?

Right in the abscence of the poper tool to relieve the valve spring tension I used .. and can I patent this.. my black and decker workmate .. simply layed the head on it with the valvespring in the wooden jaws... and bobs my aunts hubby..
The valve is burnt with a small piece missing .. did a quick look on the other cylinders and they are all ok .. well at leaast not burnt out like this one is .. So now off to shops to get a new valve & head and rocker gasket, the later because it is splitting in places near the inlet manifold.

wish me luck

hmm, might as well get new head gasket, exhaust manifold gasket, and the gasket that goes down to the exhaust pipe .

My brother use a mallet, and tap them genelty to get them off.