I have a 1977 Fiat 127, 900cc. While using the car last Sunday I was driving in slow moving traffic for about an hour and the oil light intermittently flashed on and off.. and eventually stayed on. Every time I turn on the car now the oil light comes on after about 2-3mins and stays on.

I've done a few checks (and yes, I dipped for oil! ) but can't figure out what the problem is. Any help would be appreciated.

try a new oil pressure switch,

hi you could see if the wire going to the switch
is broken or split or even making a poor connection.

If you`ve done the checks, then all guesses would be the oil pressure switch down by the oil drain plug.

Thanks guys! Will give that a shot.

they can start to fail, i change mine every few years,as they dont cost to much, my 130 Coupe had the same problem,

The one in my 125 went while I was out on Castle Combe circuit. We guessed it was the switch because the engine was doing 7000 rpm at the time and con-rods failed to appear through the bonnet. So we knew there was some oil pressure at least. Changed the switch when I got home and the light now goes out on the starter.

Part's cheap at your local motor factor, I think it's a common part for all "old" Fiats so if they don't have one for a 127, try 131, 132 or whatever they list. Panda or Uno 903 is likely to be the best shot.

Mine had a small "weep" of oil from the top where the wire plugs in indicating that the switch diaphragm had failed and was allowing oil to bypass it.

Of course, it could be that the switch is fine and is actually telling you that your engine's knackered.

I changed the oil light switch and all seems fine now ... but...

When the car is ticking over for 10+ mins and I turn it off, it won't restart. Same thing if I leave the car off but ignition turned on for over 10 mins. It eventually restarts after about 30-40 mins.

Anyone got a clue why this is happening??

Could be one of several things- without seeing the car obviously difficult to tell. But does sound like the plugs are getting contaminated in either fuel or oil. Fuel -if the carb is running too rich.; Oil- if oil is bypassing the piston rings( obviously the more serious of the two.)


Once the car has been given sufficent time "to dry out it will start".

However, there is a possibility that the plugs are receiving insufficent current to give a decent spark to discharge them in the first place.

Let the car run for a while, then inspect plugs for condition, as a starting point.If you need a guide to determine the fault, a haynes manual usually has a chart to point you in the right direction.

Keep us up to date on progress. Cheers

could be the petrol pump getting weak, with the car being hot, a weak pump wount be able to pump petrol to well, My 125 did this, replaced it and fine now.

hi Joe
Annother thing too look at is, at idle or with ignition on and engine not running, i have found that the ignition coil can get hot and sometimes over heat and stop working properly, whilst the engine is still running it needs very little power to continue idleing but as you try to restart it may not produce a good enough spark.
when the symptoms happen again check the fuel supply ( V carefully! ). you can do this by taking the airfilter top off and with the engine not running looking down into the carb as you open the throttle, you should see a jet of fuel go down into the manifold.
Check to see if the coil is getting warm,then check for a decent spark by carefully holding (with insulated pliers or equivalent) one of the leads by an earthing point as the engine turns over.
otherwise use the Haynes flow chart as Martin suggested.
good luck with it
Tim Milnes

could be HT lead braking down, as stateed get hold of an Haynes book, start with the simple checks, as Martin said, it could be plugs, not much to go wrong in the pre-the "computer-says-no" days!

Quote:
"Same thing if I leave the car off but ignition turned on for over 10 mins"

If that's the case, it cannot be a fuel related or spark plug problem nor anything else but the coil really. The only thing "working" with the ignition on and the engine not running is the coil which will get quite hot. I don't know if 127s have a ballast resistor but if they do you can suspect that as well otherwise change the coil. Incidentally, you shouldn't have the ignition on without the engine running for long periods of time as it doesn't do the coil any good at all; it will overheat and eventually die.

Yes Theo's absolutely correct - the ignition shouldn't be left on without the engine running as it damages the coil. That looks a likely suspect, so change that first.

The points and condenser are other possible suspects - a failing condenser can cause similar symptoms.

Presumably the starter motor is ok? A weak one can struggle with a hot engine (my Palio struggles sometimes after stopping for petrol following a motorway run).

Pretty much everything on the ignition system has a very limited life on a 127 - I suspect the modern replacements aren't up to the job as this never happened in the past! HT leads usually last about 12 months so it's always worth replacing those too. When I start having trouble I tend to do the lot plugs/leads/points/rotor arm/condenser and often the dizzy cap too! For the small cost it's easier in the long run, plus you have a supply of emergency spares for later.

Hope this helps, Gavin.

The fact that your car won't start until it's cooled down and especially after you've left it stood with the ignition on (bad idea, why would you do that?) points directly at the coil.

Had this problem with the "Mushy Pea" 126 I owned about twenty years back. Car would actually grind to a halt after more than 5 miles as the coil got hotter and hotter. Only worked out what it was when I jetwashed the usual oil slick off the engine and accidentally "cooled" the coil by getting it wet.

Next time it does this, try squirting WD40 at the coil to cool it and see what happens.