Okay, I tried what the FAQ told me re. adjusting the TPS and here is what happened - I couldn't do the .15 mm and .45 mm feeler guage thing - the larger was fine, but the smaller wouldn't work. The click only happens with a smaller feeler guage. Also, if I follow the manual I have (Volvotechinfo manual)it says to use a .25 feeler guage first, adjust the stop screw and the TPS accordingly and what happens when I take out the feeler guage is that the throttle plate is stopped by the TPS not the adjustment screw on the throttle body. That isn't supposed to happen, as far as I know.

However, I also tried pinching off the hose between the air intake and the idle air control valve and the idle (which started at around 650) dropped suddenly to about 300 or so (though the car didn't stall, amazingly), but I didn't know if I should adjust something at that point. When I removed my plastic hose pliers, the car stalled immediately, but was able to start right up again. That means, doesn't it, that the TPS and IAC are working? (Both are brand new Bosch OEM parts, and yes, they are identical to the ones they replaced.)

Here is my question: When I pinch off the hose and the idle goes down so low, should I do something to try to raise it to the 450-500 level the FAQ talk about (i.e. adjust the stop screw)?

The second question is, why does my idle sometimes surge slowly to 1100 - 1400 RPMs when I put the car in park? It then stays there until I turn the car off. The base idle of this car seems to be about 600 - 650 when in gear, and often when in park or neutral. It dips below 600 to about 500 - 550 when the A/C is on but usually recovers back to 600 or so.

This is driving me nuts!

To recap: I am supposed to adjust the idle first, using the adjustment screw, and THEN the TPS, while attached to the car? I have been adjusting the TPS on the bench and then installing it in the car (don't laugh if that is a dumb thing to do, it is just a lot easier than doing it in place), and it clicks when the throttle wheel just comes off the stop. T H A N K S ! ! !
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Darius in Albany NY '86 744 GLE (172K); '91 745T (161K)