ISV Opened (Pictures)
12-21-2009, 02:22 PM
#1
Instructor
Thread Starter
ISV Opened (Pictures)
I managed to get the ISV out of the car today and first tested the resistances as per the article here: BemariM3Ex - BMW M3 E30 EXperiment + more I believe this is the same ISV system used in the 944. Other references state that the testing is the same, such as here on Pelican.
I have resistance across one set of terminals but not the other two. Probably has something to do with this:
I don't think the top piece should be melted like that, do you? I am going to attempt to clean the terminals inside the cap and the contacts on the ISV to see if perhaps it's just aesthetics which are damaged. Tests on the transistors on the DME also suggest they are blown too.
Later: I cleaned up the terminals on the ISV itself and inside the cap, but now I don't get any resistances across any of the circuits. Hmmm.
I have resistance across one set of terminals but not the other two. Probably has something to do with this:
I don't think the top piece should be melted like that, do you? I am going to attempt to clean the terminals inside the cap and the contacts on the ISV to see if perhaps it's just aesthetics which are damaged. Tests on the transistors on the DME also suggest they are blown too.
Later: I cleaned up the terminals on the ISV itself and inside the cap, but now I don't get any resistances across any of the circuits. Hmmm.
12-21-2009, 03:16 PM
#2
Instructor
Thread Starter
And here it's all cleaned up.
Update: I managed to get all three circuits to read properly now (20 Ohms, 20 Ohms, and 60 Ohms), which is definitely a step up from before where only the "close valve" circuit would operate. Now both do properly.
Update 2: I have managed to get it to read properly on all 3 circuits, but only for a short time. As soon as I use a pulse to close the valve, the other 2 circuits revert back to infinite resistance. I think something's up with the arms inside the cap, but I can't do anything about it because the cap is in the way when it's all closed up! Also, working with magnets makes it hard too.
Request
Can someone who has an extra ISV measure the resistance across pin #1-->pin#2? Then measure pin#2-->pin#3? Then measure pin#1-->pin#3? That would be AMAZING if you coud. You should see closed circuits with resistances between 20 and 60 ohms. If any of them are infinitely resisted (open circuits), please let me know!
Update: I managed to get all three circuits to read properly now (20 Ohms, 20 Ohms, and 60 Ohms), which is definitely a step up from before where only the "close valve" circuit would operate. Now both do properly.
Update 2: I have managed to get it to read properly on all 3 circuits, but only for a short time. As soon as I use a pulse to close the valve, the other 2 circuits revert back to infinite resistance. I think something's up with the arms inside the cap, but I can't do anything about it because the cap is in the way when it's all closed up! Also, working with magnets makes it hard too.
Request
Can someone who has an extra ISV measure the resistance across pin #1-->pin#2? Then measure pin#2-->pin#3? Then measure pin#1-->pin#3? That would be AMAZING if you coud. You should see closed circuits with resistances between 20 and 60 ohms. If any of them are infinitely resisted (open circuits), please let me know!
Last edited by ExitWound; 12-21-2009 at 05:40 PM.
