MIJ,

Sorry for the long post, but

Today, we attempted a little troubleshooting. The connector at the MAP sensor has three contacts (they are even labeled 1, 2,3). Yes, #1 was ground and the other, #2 was output voltage, and #3 the 5v supply. Great. At ignition key pos 11 the output at #2 was back probed and measured at .65v. However, when the car was started and the throttle was applied - just stayed at .65v and never varied. OK, so there seems to be a problem.

Next step was to check for vacuum. As far as I could tell the MAP sensor is fed vacuum through a steel piped vacuum line which changes to typcial vacuum hose which runs along the bottom opening of the fan shroud and terminates at a right angle connector just above the transmission cooler line on the driver's side of the radiator. This vacuum connector is "fed" vacuum from a hose off the intake manifold. However, the right angle connector also is fitted with an electrical connector which I assume delivers power to an internal solenoid which presumably controls, like an on off switch, vacuum, because initially at startup vacuum did not pass through the connector.

So what I did was disconnected both vacuum lines at the connector and reconnected them with a short internal section of small dia pipe, thereby bypassing that right angle connection and solenoid to ensure I delivered vacuum to the MAP sensor.

Did the output voltage change at idle to higher rpms, as I would have expected: NO............ So do I assume the sensor is bad?

Also can I assume that the soleniod at the right angle vacuum hose connection operates only after a period of time, maybe with warmup with a temp sensor? I suppose I could apply 12v to the two contacts at this connector to check it's operation. Should this be the case, why? Or am I mistaken?

Anyway, as I progress further with this, I will continue to post in the hopes it helps you or someone else. If anyone can chime in with additional know-how, I'd be just delighted. This really doesn't look to be a difficult problem.

Thanks again,

Marty Wolfson
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93 244 - 118K, 93 244 - 195K, 93 245 - 120K (In Ca now) 99 V-70 - 93K