Leaderboard

Hello All, I'm looking for a tried and true test write up for bench testing the Idle Air Control IAC valve (AKA Idle Speed Control ISC) off a 1994 LS400 (165K miles) Part # 22270-50020. The 50020 IAC has the fixed coil mounted to it unlike the earlier LS400 that has the 3 screws holding the coil on the IAC; part # 22270-50010. I have attempted the bench test from Alldata but I'm not getting the desired results. My IAC measures 44 ohms for each of the 4 windings which according to Alldata is too high. The IAC doesn't function when I apply DC to the valve motor to move the valve open or closed. I could have a bad IAC but with reasonable and four even resistance readings I'm thinking I may be doing the valve test wrong. Resistance test from Alldata: terminals B1-S1; B1-S3; B2-S2; B2-S4 all should be between 10 to 30 ohms. I've seen a posting that appears to be a lexus manual giving a range of 34-54 ohms. All four of my windings are right at 44 ohms. Valve operation test from Alldata: Connect battery (+) positive to terminals B1 & B2, and the (-) negative to terminals S1-S2-S3-S4 in that order. The valve moves in the closing direction. Connect battery (+) positive to terminals B1 & B2, and the (-) negative to terminals S4-S3-S2-S1 in that order. The valve moves in the opening direction. I have one of each (50010 & 50020) IACs. When I do the valve operation test I can hear, feel, and see the valve bump (more of a wiggle) but that's it. I tried pulsing the the Negative in the sequence described but nothing. The 50010 gives me a little harder bump than the 50020 but neither move open or close. I'm assuming/guessing that I should be able to see the valve move open or closed when I apply DC to the valve motor in the correct sequence. If anyone has performed this test successfully I would really like to hear from you and know if the valve should move with DC applied. Thanks.