UK-POLOS.NET - THE VW Polo Forum

Hello,

I have a Polo Squareback 1989 with 72,000 miles on the clock, its the 1045cc model (or something similar). The car has been running fine for the last 12 months, all though the carb had frozen on a long 300 mile motorway journey about 3 weeks ago. More recently the car has been losing power, this tends to happen on motorways, the car has been fine in long journeys in the past upto and around 90 mph but in the last week, it frequently has no or little accelreration. As soon as its on a hill speeds rapidly drop to below 50mph and on a flat sometimes with the accelrator right down on the floor there is no extra power, if the car is left standing for 5 or so minutes all seems well again, but after another 30-40 miles the problem often occurs again. It has been suggested to me that it's an alternator fault, the belt isn't loose but there is some play in it. I intend on changing the alternator belt and tightening it up a little. Could the problem be with the carb, the car has had a new fuel tank, fuel filter, oil filter, air filter, brakes, coolant change and today was flushed through with Redex. Any ideas?

On short journeys I have had no problems, its just really annoying having to stay in the slow lane in case alll your acceleartion goes and then having to stop in the hard shoulder because the car drops in speed to less than 35mph.

First thing to look at is the exhaust shroud, these often corrode through.

I think if it would be a carburetor problem then the most dangerous temperature is +7 degrees Celsius for that.

I don't remember why, but I've read that somewhere.

It is mainly when it is raining?
The alternator belt might also slip easier when it's wet weather.

Anyway, there are two small hoses on the on the lower side of the air filter box, nearby where the larger hose of the crankshaft ventilation ends into the air filter box. Are they connected properly?

There might also be other parts responsible for switching form cold air to hot air. If this mechanism doesn't work properly, then the cold air might freeze your carburetor.

I think in the Haynes manual is a description how to check the temperature sensor of the air inlet and the related mechanism, but I've never done it.

P.S.
I had a similar problem once with a Citroen 2CV many years ago, and this occured even in hot summer, but I didn't find out what is was.