Red Boris Posted 21July, 2017 Report Share Posted 21July, 2017 Hi GuysFixing Airflow Meter on a 964Within the first couple of weeks of taking charge of my new red baby, I was experiencing (very) occasional engine failure on going round a corner, followed by a hunting idle. After weeks of pinning down, we finally got the issue down to the air flow meter. Chris up at Weissach in Coburg, kindly lent me a spare unit to substitute and test. Thanks Chris.. From then on , No issues. So we'd found the problem.However I couldn't afford to spend $2000 on a new a/f unit. So I put my old unit up on the bench, stared it for an hour, and then thought w.t.f. Carefully plied the plastic top off with a stanley knife. There's actually some a youtube on servicing the unit for a 944. The airflow meter on the 964 seems essentially the same.The trick seemed to be to bend the copper contact just enough to touch fresh magnetic surface on the arc.This seemed reasonably straight forward with careful hands. So top back on with some sillaflex and back onto the engine. Not a single missed heartbeat for the following 3 years...'til a month ago. But I had the routine now. So out came the unit again for a quick adjustment.Interestingly, there's some Porsche press release for '964s experiencing intermittent engine failure (I'll try to dig it out and post it). The recommended remedy is to heat and sever off the wire housing boot at back of airflow unit and clamp it close with a plastic tie wire. The theory seems to be the the terminal joint was susceptible to electrical interference from the back.So while the unit was out I decided to do this as a precaution.Absolutely no issues since.For any one with a similar experience, I hope this encourages them to repair rather than replace the unit. I've put some shots on Flickr (below) to show how it looks.https://www.flickr.com/gp/157059765@N07/3g8gMQ Link to comment Share on other sites More sharing options...
Tit Posted 21July, 2017 Report Share Posted 21July, 2017 Link to comment Share on other sites More sharing options...
clutch-monkey Posted 21July, 2017 Report Share Posted 21July, 2017 i'm just going through this now, though my solution is not so helpful. Bought jenvey ITB's, mounted the manifold on top, and throw the AFM in the bin. Link to comment Share on other sites More sharing options...
tomo Posted 21July, 2017 Report Share Posted 21July, 2017 i'm just going through this now, though my solution is not so helpful. Bought jenvey ITB's, mounted the manifold on top, and throw the AFM in the bin.I would like to upgrade to a hotwire set up like the 993, A mate had adapted the 993 hot wire setup along with 993 headers and heater boxes to his 964, Man that thing could go. Link to comment Share on other sites More sharing options...
firstone Posted 21July, 2017 Report Share Posted 21July, 2017 Hi GuysFixing Airflow Meter on a 964Within the first couple of weeks of taking charge of my new red baby, I was experiencing (very) occasional engine failure on going round a corner, followed by a hunting idle. After weeks of pinning down, we finally got the issue down to the air flow meter. Chris up at Weissach in Coburg, kindly lent me a spare unit to substitute and test. Thanks Chris.. From then on , No issues. So we'd found the problem.However I couldn't afford to spend $2000 on a new a/f unit. So I put my old unit up on the bench, stared it for an hour, and then thought w.t.f. Carefully plied the plastic top off with a stanley knife. There's actually some a youtube on servicing the unit for a 944. The airflow meter on the 964 seems essentially the same.The trick seemed to be to bend the copper contact just enough to touch fresh magnetic surface on the arc.This seemed reasonably straight forward with careful hands. So top back on with some sillaflex and back onto the engine. Not a single missed heartbeat for the following 3 years...'til a month ago. But I had the routine now. So out came the unit again for a quick adjustment.Interestingly, there's some Porsche press release for '964s experiencing intermittent engine failure (I'll try to dig it out and post it). The recommended remedy is to heat and sever off the wire housing boot at back of airflow unit and clamp it close with a plastic tie wire. The theory seems to be the the terminal joint was susceptible to electrical interference from the back.So while the unit was out I decided to do this as a precaution.Absolutely no issues since.For any one with a similar experience, I hope this encourages them to repair rather than replace the unit. I've put some shots on Flickr (below) to show how it looks.https://www.flickr.com/gp/157059765@N07/3g8gMQ Well done. Love to see the ingenuity. Link to comment Share on other sites More sharing options...
Stew F Posted 22July, 2017 Report Share Posted 22July, 2017 Agree @firstone this is the sort of stuff I want to see more of on here. Link to comment Share on other sites More sharing options...
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