jamesallum

Hi chaps

Any idea why twice I have had sudden loss of power in wet conditions? Feels as is if a fuel problem. Doesn't last for long (several seconds) but enough to bother me.

Thanks for the ideas,
James

1990 964 C4 Manual

kdfwagen

maybe water on the MAF?

crg53

James, is it a complete power loss, as in "the engine dies" or is it a loss in response when you step on the pedal; if it is the latter there are several threads on this issue. The consensus is, the AFM needs some attention, it could be dirty or you could have a bad connection.
Mine does it ones in a blue moon, mostly when coasting downhill and the getting back on the throttle, but like you said, it only last a few seconds.

DaveK

I had this intermittently for many years. I "fixed" it several times, only for it to come back a few months later.

It hasn't come back since the last time I fixed it - so I think this time I finally got it. For me, it was the TSB for the AFM - it looked like it had been half carried out, but not enough to stop the oil pipe touching the AFM connector.

http://www.pcarworkshop.com/images/b...0590geolab.pdf

Marc Shaw

Another issue may be the O2 sensor - if a cheap aftermarket sensor (non-Bosche sensor) that is not plunge-proof gets wet, it'll give you problems.

Marc

frankvan

+1 on the O2 sensor. Get the bosch original. I think water can get into the wires where they enter the actual sensor. Mine actually got to the point where it blew the fuse which is also the fuse for the fuel pump. (I spent alot of time diagnosing the fuel pump, then replaced with Bosch O2 and problem went away).

if it happened in all conditions I'd agree with the AFM problem. There is an excellent writeup on AFM's on a 944 web site (that I don't unfortunatley have the link to) as well as the wiring TSB mentioned above.

jamesallum

Thanks chaps. As ever sound advice and good lines of investigation.

Cheers,
James