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Calling all ecu gods!

I've been reading the How-to section like a good book and am strongly considering performing the FIAV/ISC block off plate mod to a spare TB that I have in an effort to fix my idle hunting. My question is if running w/out an ISC can damage the ecu? One website I have been reading says that running with a bad ISC can hurt it, but what about no ISC?
 

BoostedAWD91

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Joined
Mar 1, 2007
Messages
2,937
Location
Danville,Pa
no it will not hurt anything. You just might have some rough idling till the car gets warm
 

I'm cool with that. I've always been one to let the car warm up anyway. The car won't idle right at all currently.
 

I just replaced my ECU due to the ISC and FIAV o-ring going out. The ECU can be damaged when the o-ring fails, which allows coolant into the ISC chamber. The coolant shorts out the ISC, which happens to be grounded through the ECU, so the drivers on the ECU end up frying. Its no good.

If I had to do it again, I would do just what you are thinking of and get the blockoff plate. You won't risk blowing the ECU and the car is that much a simpler machine, at the cost of a temporarily rough idle.
 

Terry Posten

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Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
You can also use JB Weld and block off all the FIAV ports but leave the ISC ports open. Then just cap off the coolant lines.

What causes the out of control idle is a bad FIAV.

That way you get the best of both worlds. No chance of water killing the ISC and ECU and a good idle that still will raise and lower with AC, good weather, power steering loads.

It will still be a little cold blooded but run much better most of the time.
 

alansupra94

Well-known member
Joined
Mar 3, 2010
Messages
1,909
Location
Wayne,NJ
Quoting akuma10408:
I just replaced my ECU due to the ISC and FIAV o-ring going out. The ECU can be damaged when the o-ring fails, which allows coolant into the ISC chamber. The coolant shorts out the ISC, which happens to be grounded through the ECU, so the drivers on the ECU end up frying. Its no good.

If I had to do it again, I would do just what you are thinking of and get the blockoff plate. You won't risk blowing the ECU and the car is that much a simpler machine, at the cost of a temporarily rough idle.



Would grounding the sensor on the chassis prevent this issue?

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