Punto peculiarities

Hired a Fiat Punto (1 year old?) whilst on holiday in Greece last week.

2 things happened which I thought strange - any ideas/comments:

(1) Drove car around 15 miles on very twisty roads, lots of steep hairpin bends. Steering felt fine. Parked to have a nose round some shops and noticed the front n/s tyre was soft, but not totally flat. Came back to the car about an hour later and as the tyre was not visibly any flatter I tried driving the car round the corner to the office of the hire company to see if they would sort it out. The steering felt very heavy, in both directions - then I noticed a red steering wheel icon shining from the dashboard. A quick ferret in the handbook confirmed that this was the electrical powering steering failure warning light. The hire company were totally useless for reasons I won't go into, so I changed the wheel (for a spacesaver - yuch!) and when I started off again, the red steering wheel icon had gone out, and the car steered normally (aside from being a bit light on one lock due to the spacesaver). Question is - can anyone explain why the power steering stopped working and then righted itself? Is it a Fiat safety feature to disable the power steering if the tyre is a bit flat, perhaps only when you stop the car for safety reasons?

(2) Same car, Punto 1.4, puncture repaired. We went "cross country" - well, up some pretty hairy rough & loose tracks, which wound steeply uphill for miles. The car handled them not too badly, but was getting a bit hot - 3/4 on the water temp guage, but well away from the red. Ambient temperature was around 33C. At times the air con was not dishing out any cool air which indicated that the engine was pretty hot, or perhaps there is a device which cuts the air con when the engine temp goes too high. Anyway, got the the end of this trail (big sigh of relief), and turned left up a fairly steep tarmac road in 1st gear. The engine just bogged down - so I dipped the clutch, gave it a few more revs and let the clutch in again - same result, it just bogged down and then stalled. I dropped back down the hill to a convenient spot and waited a couple of minutes with the engine running, figuring it would cool faster with the water pump running than without. Tried again and it seemed to pull better, but not well - I kept my foot down on the throttle then it gradually picked up and eventually returned to normal. Question is - why did this happen? Is this a safety feature to prevent engine damage, perhaps the ECU limits the power to reduce overheating - in which case I'll be avoiding Fiats completely in future because it's a bloody dangerous feature! Or perhaps the temp gauge was under-reading?

I'm beginning to wonder if manufacturers are getting just too clever (or is that not clever enough?) with ECU equipped cars, having found my Zafira got stuck in the sand two years ago because the Traction Control wouldn't allow the wheels to spin off the loose sand in order to get down to the firm stuff underneath.

Biggles

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Biggles
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The message from Biggles contains these words:

A friend of mine hates the traction control on his Disco for the same reasons.

Reply to
Guy King

Or of course it could be the electric-hydraulic power steering the punto has was dodgy and the rest of the car suffered with lack of maintainence, like many 'non-mainstream' hire cars. The Punto does not have an unblemished reliability record.

I suggest that the next time you hire abroad you choose the VW Polo on the hire fleet, or hire through one of the big hire chains.

Artie

Reply to
Arturo Ui

You haven't mentioned the altitude at which this happened. Perhaps the air was rather thin there and this commonly results in a sharp decrease in power from naturally aspirated engines.

Huw

Reply to
Huw

Polo wasn't an option, and they don't come much bigger than AVIS do they?

Biggles

Reply to
Biggles

Interesting thought. We were on the island of Samos - couldn't have been more that 1200 metres, which is the max altitude of the bit we were driving in. I don't see how that would explain how the problem resolved itself? BTW when I said "dropped back down the hill" it was 40 metres or so.

Biggles

Reply to
Biggles

1200 metres is quite high. The engine probably ran too rich and what you experienced was similar to running an engine with too much choke, coughing and spluttering cured for a few moments by a quick blow-out and a few revs.

Huw

Reply to
Huw

Your explanation sounds plausible, although I didn't detect the normal signs of rich running (lumpiness, misfiring etc) just lack of power. I thought engine management systems were supposed to be able to cope with this - the Lamda sensor should provide continuous feedback to correct the mixture? I suspect you are right though, I managed to take the car outside of the parameters it had been programmed for. I'm just glad I wasn't stuck halfway round a steep hairpin bend when the engine decided it wasn't going to play ball.

Biggles

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Biggles

message

Erm we havent been using carbs for almost a decade now!

Altitude compensation is one of the most fundemental atributes of a fuel injection system.

Tim..

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Tim..

It can only compensate by lowering fuel injection and power to a point unless the engine is turbocharged.

Huw

Reply to
Huw

Of course, but your post related to the engine bogging down due to a rich mixture due to thinner air at altitude.

Tim..

Reply to
Tim..

I am not familiar with the engine mapping for the vehicle concerned but it is possible that either the envelope for lowest fuelling was breached in relation to air density or that the air density range was exceeded or a combination of both. Of course there could also have been a sensor or other calibration fault or it could be something else entirely. Also I am not entirely sure that air density is in fact measured at all in some cars which measure air volume only. If you have a different and more probable hypothesis then we shall all be pleased to hear it.

Huw Huw

Reply to
Huw

You weren't the guy in the queue in front of me refusing to take a hire care because there was a dent in the door were you?. Hire cars are so cheap that maintence is minimal - just enjoy chilling out.......................

Reply to
john

Not me.

Huw

Reply to
Huw

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