LI-SVT Posted November 29, 2004 Share Posted November 29, 2004 I am having trouble diagnosing my IMRC problem. About 10 seconds after start the secondaries are opening. They close with the engine off. With the key in the run position and the engine off they stay closed. I tried to look at the open/close signal coming from the computer. I don’t see one. Is it an open collector output from the computer? If the computer knows the box is open will it send the signal anyway? Right now my suspicion is the IMRC box is malfunctioning and opening on its own. All the mechanical aspects are clean and operate smooth and free. Thanks in advance! Link to comment Share on other sites More sharing options...
Terry Haines Posted November 29, 2004 Share Posted November 29, 2004 ....sounds like the imrc circuits in the box have a problem...I'd double check the connections to the imrc unit but it sounds like a new part is in order... Link to comment Share on other sites More sharing options...
LI-SVT Posted November 29, 2004 Author Share Posted November 29, 2004 I would like to "see" the computer try and open this thing at ~4000 rpm. This way I am sure its the IMRC box. I would hate to spent $100 on the wrong part. You are pretty sure its the IMRC box itself? Ever seen this particular symptom? I don't like swapping parts without troubleshooting. Link to comment Share on other sites More sharing options...
BuckeyeSVT Posted November 29, 2004 Share Posted November 29, 2004 I would like to "see" the computer try and open this thing at ~4000 rpm. This way I am sure its the IMRC box. I would hate to spent $100 on the wrong part. You are pretty sure its the IMRC box itself? Ever seen this particular symptom? I don't like swapping parts without troubleshooting. /> Over the years the circuit board wears from heat and use. There is a Black/Red stripe wire that the PCM grounds to open the IMRC. You can unplug the IMRC connector while the engine is running (while it is holding it open) and check for ground (using a multimeter) on that wire to see if it's the computer or IMRC itself.No ground on that wire, not the computer/wiring.... If Ground, you have other issues. -Dom Link to comment Share on other sites More sharing options...
LI-SVT Posted November 29, 2004 Author Share Posted November 29, 2004 I will double check the bk/rd wire. I did check it poking around and I remember it being always grounded, not a good sign! I will post the findings and let you know where I stand. Thanks for the advice. Link to comment Share on other sites More sharing options...
Terry Haines Posted November 29, 2004 Share Posted November 29, 2004 ....oh joy!...a potential wire harness issue....run!!! Link to comment Share on other sites More sharing options...
LI-SVT Posted November 30, 2004 Author Share Posted November 30, 2004 OK, here is what I found: /> >The black/red wire is not shorted to grd . >key on engine off the bk/rd wire has 12V on it. >key on engine on the bk/rd wire is 0V. >At no time does the bk/rd wire ever go to ground. I tried to "see" some kind of transition at the bk/rd wire crossing the ~4000 RPM point. The voltage never switched and the continuity to ground never switched. Help Link to comment Share on other sites More sharing options...
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