Surging and Unsettled Idel after MPS Rebuild, '74 2.0L D-Jet Options

[914four]

Running down a bucking issue and found my MPS to be leaking. After rebuilding the MPS and verifying a good seal, everything went back together okay. When I started the car, the engine surged up and down and would not idle.

The electrical connector socket on the MPS does not appear to be keyed and using the diagram below from Clay's D-Jet troubleshooting guide it seems I may have plugged in the MPS wire incorrectly. I ohmed the wires from the ECU connector to the MPS socket and made sure the wires are in the order shown in the diagram.

The wires look to be looping back from terminal 7 to 15 and 8 to 10 so that the socket could be plugged in either way and work correctly. Could plugging in the MPS wires incorrectly have damaged the ECU? If not, what should I be looking for that would cause the surging and lack of idle?

[pbanders]

You can't plug the MPS in incorrectly, you didn't damage the ECU. Wildly varying idle makes me think first of a vacuum leak. Have you checked carefully to make sure you didn't inadvertently pull a vacuum line off when you were swapping the MPS? Suggest you check my page (see sig) and others to make sure you have the vacuum hoses right, and that all components in the D-Jet are correctly connected and functioning. Take a look at the idle mixture adjustment knob on the ECU, you may have set it to full lean when your MPS was malfunctioning/leaking (which makes it rich), and now you're full lean. There's an indicator on the knob, try setting it to the middle of the range as that's the "factory" setting, about 3% CO.

[914four]

You can't plug the MPS in incorrectly, you didn't damage the ECU. Wildly varying idle makes me think first of a vacuum leak. Have you checked carefully to make sure you didn't inadvertently pull a vacuum line off when you were swapping the MPS? Suggest you check my page (see sig) and others to make sure you have the vacuum hoses right, and that all components in the D-Jet are correctly connected and functioning. Take a look at the idle mixture adjustment knob on the ECU, you may have set it to full lean when your MPS was malfunctioning/leaking (which makes it rich), and now you're full lean. There's an indicator on the knob, try setting it to the middle of the range as that's the "factory" setting, about 3% CO.

Thanks for the assurance I didn't kill my ECU and direction. I'll use you webpage and go back through the vacuum hoses and connectors to see if I left something off.

Kelvin