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Concerning the part about the pressure switch....why are we getting backwards readings?? We repeatedly tested the part.....it would read 0 when there was nothing happening to the switch, and would read infinity when there was suction on the air hose.....the book says in two different places it is supposed to be the other way around.....does anyone know what is happening here?? :( Becky '69 FI AT Fastback > On 8 Mar 98 at 11:40, northaven@worldnet.att.net wrote: > > > I have a '69 fuel-injected automatic Fastback. When I drive at > > freeway speeds my engine has sudden extreme losses of power. If > > I pump the gas pedal while it is having its power loss the > > engine will die. This problem has become so frequent and the engine > > dies so often I don't think it will get me to work on Monday unless > > I figure this out. > > > > We ran a some of the fuel-injection electronics diagnostics per the > > "How To Keep Your Volkswagen Alive" book and we discovered that the > > pressure switch (lives under the right-hand pair of manifold tubes) > > was disconnected from its electical connection. Upon reconnecting it > > we found it to read the opposite of what the book said it should > > read. it read 0 ohms when left alone and infinity when the tube was > > sucked on. The book stated it should be the other way around. > > This is easy to get confused about, but I think it is impossible for > it to be backwards. This switch was only used in 68-9, and, while > there may have been more than one version, they are all > interchangable. > > > We tried running the car with the pressure switch plugged in and we > > couldn't even get it down the street. It died and refused to start > > and stay running. We had to disconnect the pressure switch to get it > > back to the house (and even with it disconnected it was difficult to > > get the car to remain started). > > > > Help, please?? > > > > The "How To Keep Your Volkswagen Alive" book said that the throttle > > switch must have a number specific to my engine, but the VW parts > > place that sold me my current switch knew nothing about that. Would > > an identical looking throttle-switch be the wrong one for my car? > > The "Throttle valve switch" is a different part. Once again there > may have been more than one version made for the 68-9s but they all > have 2 terminals and they all interchange. (And they all have the > same Bosch part number.) > > > Any help as soon as possible would be appreciated. > > Check your electrical system. Put a voltmeter across the battery > and rev the engine until the voltage won't go any higher. At this > point the voltage should be above 14 V. If it is not, replace your > voltage regulator. This can have amazing effects on the EFI. Cars > where the regulating voltage has fallen to 12.5 V can become almost > undrivable. This goes hand in hand with running very rich (poor gas > mileage.) > > If your gas mileage has been good, next time it loses power at speed > try shifting into neutral for a moment and reving the engine briefly > with no load; this can cool off an overheated (running lean) engine > and give it a temporary new lease on life. > > Bad/butchered electrical FI connections are the bane of the > D-Jetronic FI. Go over everything carefully and make sure that all > the wires are connected to the right places. On the 68-9, there is > a FI wire that runs to the starter. Make sure that wire is on the > starter terminal that is only hot while the starter is cranking. > > Jim > - > ******************************* > Jim Adney, jadney@vwtype3.org > Madison, Wisconsin, USA > *******************************