Who has Bench Tested an ISCV?

[suprabee]

I'm bench testing my ISCV per the TSRM here:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=107

I can not get the valve to open or close by the method described in the TSRM. I removed the valve after normal engine shutdown, so it is in the open position.

This test is straight forward in my opinion. Does this test actually work? has anyone tested the ISCV with this method and get the motor to move?

the resistance of B1 amd B2 reads within spec at @22 ohms.

I initially interpreted the TSRM to first attach a ground to S1, let the motor step, then remove that ground and attach it to S2, let the motor step and so forth.....

So, after getting no movement, I thought maybe the TSRM means to leave the first ground attached to S1, attach another ground to S2, an so on, but that also did not result in motor movement.

I'm in the process of working my way to the valve stem seals among other gaskets and was just checking the ISCV since it was off the engine. I had no idle issues.

anyone?

Thanks,
Rick






anyone?

 

[Scruggs86.5T]

I have tried this before and it seemed to work fine for me. The motor actually moves just a little bit with each step between the S terminals as you go along. This might be a stupid question, sorry if it is, but are you attaching the +12v to terminals B1 and B2 when moving a ground wire from S1 then S2,S3,S4 all in sequence. Also the resistance measurement that the TSRM tells you to check is across B1 to S1 and/or S3, and then measure across B2 to S2 and/or S4. Hope this helps a little, good luck......

 

[suprabee]

are you attaching the +12v to terminals B1 and B2 when moving a ground wire from S1 then S2,S3,S4 all in sequence.

Yes

Also the resistance measurement that the TSRM tells you to check is across B1 to S1 and/or S3, and then measure across B2 to S2 and/or S4. Hope this helps a little, good luck......

Yes I am aware of that.

rick

 

[supradjza80]

sounds like the valve is faulty if your doing the test correctly.

 

[Scruggs86.5T]

Sorry, I took this

the resistance of B1 amd B2 reads within spec at @22 ohms.

as you measured resistance across B1 and B2 and got 22 ohms. I would say its bad then.

 

[suprabee]

Dave,

i just attempted a test again, and this time I "felt" the iscv while applying the voltage in sequence and I could feel the motor moving.

So, then I looked very closely and could see the armature moving every so slightly, at each movement of the ground wire.

So it is in fact moving open and closed, but only by a maximum of maybe 2 millimeters. Did your move more? How far did the arm move?

Rick

 

[suprabee]

Sorry, I took this

as you measured resistance across B1 and B2 and got 22 ohms. I would say its bad then.

No, I meaured the resistance per the TSRM ( B1 to S1 or S3 and B2 to S2 or S4 should be 10-20 ohms)

I measured @22ohms for each case.

how far did your arm move?

rick

 

[Scruggs86.5T]

I really couldnt tell you, its been a long time, if I remember right it didn't move that much, what yours moved sounds about right.

 

[suprabee]

I really couldnt tell you, its been a long time, if I remember right it didn't move that much, what yours moved sounds about right.

Ok thanks,

However, I think that my ISCV armature is not moving enough. When I step the motor to the "closed" position, (recall it only moves at most 2 mm), the valve itself still allows me to blow air through it. I would assume that at a fully "closed" postion, I should not be able to do so, thus, my armature is sticking with buildup or the motor is bad, or both.

I'm gonna take it apart and see what a cleaning does, but it would be good to know ideally how far it should move.

So, the question now stands to others..
How much should a normally operating ISCV armature move?

Rick

 

[suprabee]

So, I disassembled the ISCV, even took apart the motor and cleaned all the gunk off the shaft and tip.

From a visual inspection, It looks like the total movement the tip needs to move (to the position where it closes against the ISCV housing body) should be around 3cm which is definitely not what it is moving.

Even after cleaning, the valve won't move either way more than 1 mm when testing per the TSRM, but I've cleaned it up so much that I know it is not sticking due to gunk, but I am still puzzled as to why the tip won't move according to the TSRM.

It seems unlikely that the coils in the motor would go bad and then rest of the motor is just the tip, shaft, a spring, two bearings and a magnet. All of which are now clean.

So, again, has anyone bench tested the ISCV per the TSRM with the results of 2-3cm movement of the tip/nipple??


Rick

 

[CyFi6]

It doesnt move much with the test procedure, just unplug the one in your car and plug the one you are testing in temporarily, start the car or turn the key on for a moment and back off and watch the plunger move, as well as click a series of times after you turn the key off

 

[DangoAZ]

Suprabee -

I've had mine apart and cleaned it per the TSRM before. I had a lot of gunk in there, and when I cleaned the crap out of it, it moved like it was suppposed to. I was really surprised at how little it moved for all of the electrical steps I was providing... By hand, you would have to pulse it until your eyes crossed to get it to move the whole distance.

Read this: http://www.supramania.com/forums/showthread.php?t=16437&highlight=iscv

Look at jetjock's post #6... If you have to pulse the ISCV 33 times per revolution, you can count the number of twists on the shaft and figure out how many times you have to pulse the thing to get it to move the full range of motion. You said it was moving "ever so slightly"... That's what it's supposed to do! When I tested mine again after cleaning, I know I only pulsed it a couple of dozen times to see it move again, and then put it back in the car. It fixed my idle issues, but I can't tell you that I saw it move the full range of motion. I just don't know who has that kind of sick patience to move it the full range by hand.

 

[suprabee]

Thanks... I;ve done what jetjock mentions with no luck. I put a little dot of white out on the pintle and in fact it does not rotate. When I apply voltage to, say the first connector S1 the motor "bumps" but does not turn the pintle, so that was what I was referring to in my earlier post as it turning, "ever so slightly".


When all apart and I have the bearing, magnet, shaft, pintle assembly in my hand, the bearings turn freely, and in fact just the force of the small spring on the pintle will cause the shaft to rotate and move the pintle outwards. However if I retract the pintle by hand and then install the bearing, magnet, shaft, pintle assembly into the windings of the motor, the pintle won't move outwards on its own like it does outside of the windings.

Looks like the thing is not working as it should,

 

[DangoAZ]

Bummer... Doesn't sound good.

 

[mstgeer]

I just when through this same dance myself. To get a definative answer if it is functioning I installed back on the car, except for mounting it to the intake manifold. Cover the hole in the intake with a pc of srcap metal (make sure it is large and stiff enough that it will not get sucked in), and had my wife crank the car over. If the valve is working, you will clearly see it move almost through its full range of motion.

 

[figgie]

255 steps

.25 ms per step (S1, S2 etc)

that is to reach full open and close.

 

[89supracrazy]

I was the same way. I thought the iscv should move alot when I bench tested mine but it moved a little at a time. I did the same thing mstgeer did. I blocked the hole in the intake and you can see the iscv moving alot.

 

[easternguy2005]

This was driving me crazy. When the engine actually starts after turning over the valve moves its full motion (1/2 inch or so) - and when it the engine shuts down it moves alot again. Just turning the key and not cranking over the engine does nothing at all.

Also when bench testing the motor if you can feel it get energized then it's good but I couldn't make it move very much