Dodgy isc motor?

[nonickname]

Hi guys,

I have just swapped the bottom of my throttle body with a replacement. I did this as my car was leaking water into the inlet manifold, It had no warm up cycle and also when I turned the steering wheel the car would drop rpm at idle. I found exactly the same part from a 3000 v6 magna at the wreckers. I installed the replacement part and for the first few minutes the car had a warm up cycle, But it wouldnt drop below 1100rpm even with the screw wound right in. Then the check engine light came on. I then replaced the magna isc motor for the original vr4 one and now the check engine light comes on after the car runs for about two minutes with this one aswel. Before I messed around with this the valve was just bypassed by a u shaped hose and the top hose by the thermostat was run down to the lower water pipe on the block. Even when this was bypassed the check engine light never came on? Any ideas?

 

[brisvr4]

Is the cel definitely for the isc? Have a look in ecmlink and it will tell you what it's for.

 

[nonickname]

Is the cel definitely for the isc? Have a look in ecmlink and it will tell you what it's for.

I would love to but the laptops at the misses place at the mo After this problem is sorted I will be getting a wideband and will finally be able to tune this thing like yourve told me...better late than never.

 

[brisvr4]

How does it run with the isc unplugged? There is a slim possibility that the isc drivers in the ecu are burnt out. ( very slim! )

 

[nonickname]

How does it run with the isc unplugged? There is a slim possibility that the isc drivers in the ecu are burnt out. ( very slim! )

With the vr4 one it makes no difference if its plugged in or not. From cold I also have to put and hold my foot on the gas to keep it running. It needs the idle screw wound out a few turns to idle at 850rpm at full temp. The only way I can get it to idle by itself from cold is if I turned the idle screw out heaps of turns but then obviously once it warms up it has a really high idle. The magna one definitely behaves different. It has a warm up cycle. From cold it goes straight to 1500 and makes its way slowly to 1100rpm but wont go any lower and thats with the idle screw wound right in and up to temp. So pretty much the complete opposite of the vr4 one.

 

[nonickname]

Awsome. Ecmlink told me it was the knock sensor connection. It had come unplugged probably while I was messing about with the throttle body.

 

[brisvr4]

lol, at least you worked out the fault!