Sharan/Galaxy/Alhambra - engine cutout for fractions of a second

Hi,

I wonder if anyone has any thoughts on a problem I'm having with my old-style (1995) VW Sharan.

Every now and again the engine dies but only for a very brief period, less than a second I'd say although I've not been timing it. The effect on the engine power is as if I'd turned the key off, the car slows very quickly, much more quickly than simply lifting my foot off the pedal. At the same time all of the electrical stuff *except the rev counter* stays completely normal. The rev counter is weird, when this happens the rev counter dies away to zero almost instantly, clearly it's not reading properly as the car is still in gear and moving so the engine must be rotating.

This fault is proving very difficult to diagnose as it only happens occasionally and only when it wants to. My guess is that if I can find out what the rev counter actually counts I'd be a long way to diagnosing it. Does anyone have any ideas?

Reply to
Calvin Sambrook
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If it's like my old T4 Caravelle, it will be the brake light switch. (there are 2). One for the back lights and one for the ECU signal. Certainly the same symptoms. Worth £9 to find out too. Did you get a codes read? Know anyone with VAG-COM? If you're in the SW, I can do a scan for you no problem.

JB

Reply to
JB

Plug it into vag-com & see what the intermittent fault (cam or more likely crank sensor) is.

Reply to
Duncan Wood

crank sensor is the likely fault.

Reply to
Mrcheerful

Seconded. Our Lupo has done this for some time, and has finally logged an 'implausible signal' for the crank sensor, so that may well be getting changed. The only answer is to get it on VAG-COM.

Reply to
Chris Bartram

Thanks to everyone who responded to this. The pointer to the crank sensor led me to research that area and it seems quite a common problem, not only that but descriptions of the fault conditions by others precisely match those I'm experiencing.

I'd very much love to read the fault codes on car but that seems to be something of a problem in its own right. It's a 1995 VW Sharan and all of the info I can find about code readers implies that OBD-II started from

1996. I've borrowed a bluetooth reader made by OBD-KEY but it refuses even to communicate which sort of backs up my feeling that its not OBD-II. The connector is OBD-II style and there are wires going to it but I've read that between 1994 and 1995 some cars were made with OBD-1.5 which used OBD-I comms through an OBD-II connector!

I'm trying to find a local garage that will do a multiple read for me (as in read-reset then read again once the fault has happened) as I've been reading that some of the more professional kit can cope with OBD-1.5.

So, I'm not fixed yet but I'm confident that I can be!

Again, many thanks.

Reply to
Calvin Sambrook

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