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Hi guys hope all is well

Sometimes when i stop at lights say, my car seems to almost stall then rev up, then almost stall and rev....and so on. Its quite intense as my mate thought i was revving the car and it virbates throughout the whole car!

I've got a 2001 6n2 1.0l

This only happens sometimes.....Mind you my epc light went on the other day...i turned her off then back on and the light went off.......could this have a connection????

Any help avaliable would be great!!

Yeah, suspect the MAP sensor.

that easy to replace? sounds expensive...

I was speaking to a parts specialist of mine for volkwagen and he seems to think it's because i have an odd number of cylinders....even cylinders cancel themselves out for something he said.

If i was to get the map sensor replaced what costs am i looking at?

cheers

i have the exact same problem...again it only happens sumtimes, but sounds really un healthy....i thought it might have been something to do with my k&n....but wasnt sure.
dan

K&N induction? It probably is. You see the MAP is the depression caused by the inlet and the valve setting. The ECU uses this to work out the load on the engine and then it does a load of witchcraft and out drops the injection timing.

Now all MAP sensors read slightly different for a given setting, so the ECU calibrates its view of the MAP by observing the maximum and minimum over a period of time. It needs to see idle and wide open throttle at about 2500 RPM (such as going onto a motorway). After that its happy. Occasionally it will get its knickers in a twist if you do not ever use WOT like me, or you change something like the air filter or induction and suddenly its giving readings that are shifted etc. Occasionally in wet manifolds (such as spi engines) the map sensor diaphram gets a puncture, other times it just has a bad day. But some VW's been a bit notorious for MAP sensors that go bonkers.

Its quite easy to fit, take off the air box and you can see it. Two screws and it has a gasket. Its essentially just a barometer, i.e. sealed bellows with carbon film printed on it. Not really expensive. But you'd really have to check if that is actually the problem. Even if the fault codes indicate strange readings from the sensor it could indicate a vacuum leak else where in the inlet manifold, which would also make the car sick.

Sometimes with the marelli ecu, you just have to plug into it and tell it to stop being silly and the problem goes away.

What you can so is the following to see if the problem goes away.

1) pull the connector off the MAP sensor and then put it back (with the engine NOT running), and this will clear any corrosion on the connector. Next time you go out, start the car WITHOUT any throttle and let it idle for a couple of mins. Then in a high gear operate at wide open throttle for a couple of seconds, (it won't go very well because of the low torque in high gear) and then see how it goes from there.

Otherwise your stuffed unless you can look at the fault codes.

I had that problem on my 6n.

Took it to a garage and was told that some part in my engine (cant remeber wat it was) had a build up of s**t around it and had to be cleaned, has been fine since

Musicfreek2002 wrote:I had that problem on my 6n.

Took it to a garage and was told that some part in my engine (cant remeber wat it was) had a build up of **** around it and had to be cleaned, has been fine since

That would probably be buildup of carbon on the lambda sensor. This is caused by idling round town, short journeys and crap fuel. The only solution (other than removing it and using oven cleaner) is to take a gentle 75MPH motorway journey for an hour or so.

Carbon on the lambda causes very specific cut outs when the car is just switching from open loop (cold) to closed loop control. It often splutters around there, usually at traffic lights on the way to work! Though the EPC light wouldn't come on.