I took the plunge on a 1993 1.6 i.e Tempra a few days ago and there is tumbleweed in the Tempra forum, there being not many left. So since they are so similar, I thought I'd post here for advice.

It has developed a severe misfire but it is intermittent. It will start and idle fine as long as you like, but when driving it will start to cough and judder. It will then fail to even idle. Sometimes it restarts but usually has to be left for hours before it will.

It has done very few miles in the last couple of years but I put over 25 litres of fresh fuel in it and it was fine for the first 100 miles. It still indicates 1/2 a tank (about 1/8 when purchased).

Could it be just the old fuel? Perhaps it is a blocked injector? I'm sure it is single point injection but I haven't started full strip yet. There is a receipt in the history for a coil pack and a fuel filter in 2014 so 2 owners ago, it seems it may have happened before.

My next suspect is the fuel pump but the fact it sometimes runs OK has led me to be unsure. I suppose I'm avoiding the issue that I may have to take the tank off and clean it out.

Any others cured such a fault?

There aren't many Tipos left either, tommo:
Post a pic of the engine with air filter hose removed if you're not sure what fuel system it has.

I doubt very much that "old fuel" is the issue.
Whatever it is, it doesn't sound too problematic.

Fuel pump pressure is easy to check.
Tank probably holds 55 litres of fuel (95 octane).

If it gets to be a real pain, I can post a query for you in the Facebook Club Fiat Tipo Argentina, a couple of very knowledgeable Fiat experts post there.

Thanks for the response. I was rambling a bit in the above post I admit. I should explain I'm an enthusiastic amateur, restored old Morris Minors in my past, stripped suspension on my TVR, and handy with spanners etc.

Problem with this car is there is no OBD socket onboard. Looks like a small diagnostic plug in the engine bay but I expect only Fiat will be able to use it.

It is definitely single point injection but this has me stumped. Used the car again today. Started first time from cold, drove perfectly. As soon as the water temperature reached about 70C, it started to run rough, and cut out. a pig to restart and ran OK for less than 1 minute. In the end, I had to park up for an hour to let the engine water temp cool down to about 50C. Then started and drove the 3 miles home perfectly!

I'm positive the thermostat is removed (or stuck open) because cruising along at 30 mph this morning, the water temp dropped to below 60C which is why it ran OK on the open road. Roadworks or heavy traffic, engine temp > 70C, it conks out!!

I'd start by checking the temp sensor that may be registering cool when it's hot, causing too much fuel to be pumped in.
Running temp should be around 90C, but it drops in my Tipo when on the open road, even on a warm day.

Better a thermostat stuck open than closed.

I don't think OBD was listed in Fiat's inventory back then.

You're so right regarding the thermostat! I had a Lotus Excel many years ago where it stuck shut and I nearly cooked the engine. I took it out to get me by and it wouldn't go above 70C, ran better actually (old Dellorto carbs).

I have a Porter manual with the car but it makes no reference to a water temp sensor, so whereabouts is it?

You could be right about it over-fuelling. I hadn't considered this but when attempting to start it after stalling, it may be flooded despite it being an injected engine where this shouldn't happen.

Water temp sensor is under the brown cover, middle of pic:

SFB said:

Water temp sensor is under the brown cover, middle of pic:

Click to expand...

That could be the temp sender for the gauge which is totally different for the sensor for the fuel injection system.
The sensor for the injection system could be on the cylinder head on windscreen side rather than radiator side, beneath warm air trunking (if trunking still on car)

Hi. The diag port is just basic obd1

See posts in bravo\a section

A popular mod in Argentina with single point injection is to bin it and fit a carburettor.

EDIT: Just found this and another interesting post here:
https://groups.google.com/forum/#!topic/alt.autos.fiat/dwPdbJE3-YU

Atlantica 18/05/2006

I have a Fiat Tempra 1.6ie SX which also has single point injection. To
retrain my ECU you have to do the following:
Start engine and allow to idle (do NOT touch accelerator when starting) and
allow to idle until fan cuts in and out 3 times. Switch off engine and
disconnect battery for 15 minutes. Restart engine and again allow to idle
until fan cuts in and out 3 times. Switch off and then restart immediately.
My ECU is then reset.

Click to expand...

More of the blind guiding the blind here:
https://www.fiatforum.com/uno/189063-wont-start-when-hot.html

Any luck with this yet,if not drop me a message on Monday,I have the service manual for the Tipo 93 range fuel injection cars.

Not many things to control the engine management on these, this seems to be a temperature issue so I'd suspect the ECU temp sensor on the rear of the cylinder head, or the wiring around it. The sensor is hard to remove with a spenner, if you use a socket you'll probably break it but they are cheap.

Also flush and refill the cooling system with a new thermostat... again cheap and easy.

Don't discount the old favourites of spark plugs and leads, you may find the correct leads are hard to locate as computer lookup systems usually get it wrong.

Getting basic diagnostics done won't be too easy these days, but it could identify faukly sensors (such as the lambda).

You can pull the fuel pump and attached filter quite easily from under the boot carpet, you can probably get a skinny arm in there to wipe around and clear any gunk.

I can go back to sleep now that the experts have arrived.
Best of luck sorting it out, tommo.

I'll stick with carburettors.

SFB said:

I can go back to sleep now that the experts have arrived.
Best of luck sorting it out, tommo.

I'll stick with carburettors.

Click to expand...

I too like carbs but not modern fuel that goes off fast and can clog carbs.

jackwhoo said:

I too like carbs but not modern fuel that goes off fast and can clog carbs.

Click to expand...

Say what?¿?¿?

Clogs carbs, must be somewhere in Holland.

Apart from removing lead, nothing much else has changed with gasoline, or petrol if you drive on the wrong side of the road.

SFB said:

Say what?¿?¿?

Clogs carbs, must be somewhere in Holland.

Apart from removing lead, nothing much else has changed with gasoline, or petrol if you drive on the wrong side of the road.

Click to expand...

Only if left unused for months/years don't worry go back to sleep

Zzzzzzzzzzzzzzzzzzzz

Update:

The temp sender shown in the earlier photo is only for the gauge. The ECU water temp sender is below the air filter housing at the back, on the inlet manifold which I presume is water-heated. For information, if you connect and disconnect it with the ignition on with the engine warmish, the idle control screw will move slightly on the other side down by the throttle lever.

Been messing today, unfortunately the sender was reading about 3k ohms cold and dropped to about 700 ohms at 60C so it's OK. It's providing 4.7V from the loom, not the 5V I expected but I don't think this is critical.

I decided to check the plugs (gaps a little bit too wide) and then the distributor cap. Looked OK at first, a bit of pitting on the 4 contacts but then I noticed the centre brush was almost worn to nothing. No spring in there either! There's a receipt for a new one in the history from 2 years ago but it obviously wasn't actually changed.

It now makes sense that the engine was spluttering under load because of a weak spark, and that when the engine got hot, the slight expansion of components, even plastic, meant the centre brush was making only the slightest contact with the rotor arm.

Could be a eureka moment. I've fitted a new one but can't road test yet because I've the dashboard out, suffering from the sticky black mess syndrome which took me hours to scrape off.

The Porter manual states that there is an OBD port in the footwell but I can't see it. There is a 3-pin lead hanging next to the ECU that seems to be a diagnosis port according to the wiring diagram (wires are the correct colours), but I only have the more modern OBD II reader.

I posted a reply in the Tempra forum.

My bet is that you've solved the puzzle.

As for ECUs and OBDs, I use them when working on later cars, but my Tipo is free of all the electronic gubbins that cause most breakdowns these days.
I never had any dealings with the early ECUs, I left them to my junior staff when we started working on later VWs, they were more interested in it than me.