ISCV Not working. Bad Wiring probably... How to test it?

[Pijus]

Hey Supramania!

I've searched a lot but could not found any threads about bad ISCV's wiring/ signal, but not it self..

Introduction:
87 Supra from factory N/A 5speed, but now with swapped engine/gearbox/ecu/harness from 89 7mgte r154 UK spec Supra.... Engine is 100% stock.

it's almost 4 months after swap and i cant get engine to idle:

Cold engine,- starts, idles low ~500-1000 range, sometimes stalls after pressing gas pedal...
Warm engine.- wont idle at all... almost every time stalls if i take off foot from pedal...

here is video to make it clear http://youtu.be/fdU0RmIrZnY

What i figured out, is that my ISCV is not working at all... it's always in "closed" position,- if i unplug connector or cap hose (ISCV-accordian hose) no different at all... also no clicking after turning off engine...
i removed ISCV, inspected it as shows TSRM ,- Resistance OK. Rotor moves if i apply voltage to terminals B1 B2 and keep grounding S1 S2 S3 S4...... , cleaned it with WD40, tested again.- Everything is 100% working per tsrm, but when i placed it back- same situation car wont idle... ISCV not working

I've taken another ISCV, the one that i now is working 100%,- from running car... i just plugged connector, without puting valve into intake... just to look if the rotor moves... but again, no luck, rotor does not moves...

I'm pretty sure ISCV is good, but it wont get right signals from ECU... maybe because of bad wires, maybe bad ecu... But how to test that?

i measured resistance of ISCV connector terminals with ignition on,- there is what i get:

S3-B1 1168ohms
S3-B2 1168ohms
S4-B1 472ohms
S4-B2 472ohms
S1-B1 No continuity
S1-B2 No continuity
S2-B1 No continuity
S2-B2 No continuity
B1-B2 1ohm
S1-S2-S3-S4 No continuity

What to do next? What is the right resitances of iscv connector? If i understand that correct there is only one pin in ecu- M-REL, which not directly send signals to ISCV?

TPS is calibrated, i get IDL signal... AFM is working, no codes at the dash or in memory...

Sorry for my langauge skills, but i'm really tired of this problem..

 

[Bmettie]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=65

You should have +12v from the ecu on B1 and B2 with ign on. S1-4 are sequential ground pulses from the ecu.

 

[jetjock]

^ This. And why would you be measuring resistance with power applied (ignition on)? To check the integrity of the wiring unplug it at both ends and check for low resistance (continuity) on each wire. To make the test faster and avoid having to lengthen one meter lead short a pair together at one end then do the same for the next pair. Or short each one in turn to ground. Same difference.

 

[hvyman]

^serious.

To check resistance you need to power down and isolate.

Check for 12v with ign on on b1 and b2 which both are b+ black/red wires.

If 12v then unplug iac connector and unplug ecu connectors and perform resistance check on the wires from the iac connector to the ecu connectors.

 

[Pijus]

What a good info there!

Thank you guys, i'll try that and report if i get any luck!