No idle help...

[Marc Swanson]

> > '88 5ktq.  Car stalls when you let off the gas pedal.  Runs fine when one
> > is driving and when holding the rpms up.
> >
> > I have checked the decel valve, and it appears not to be a problem.  I
> > disconnected the large hose, and plugged the hose and the valve.  Same
> > stall result.



Well, I can add another possibility.  I had a problem on my 4ktq (running an 
MC engine with the ISV and fuel system from the 5kt) and ran through the 
diagnostics in the bentley and referred to SJM's excellent troubleshooting 
pages.

The issue in my case turned out to be a flaky connection to the temp sensor 
mounted on the coolant flange (the single pin one on top.. there is an 
identical one on the head that is used by the ECU).  I found this out by 
going to measure the resistance with the ignition on and reading the current 
going through the ISV.. all I had to do was barely touch the wiring leading 
to the sensor and the ISV would quit.

Remember that if pretty much anything in the ISV circuit goes haywire, the 
unit WILL not work again until you restart the car (like some computer 
operating systems I know...).

All I did was crimp a new connector onto the harness and it is working great 
again.  Your issue may be something else.. but this is just my recent BTDT.


Good luck and keep us posted.


-Marc-
87 4ktq
88 90q