Possible ECU issue?

I finally got 1082 up and on the road again thanks to thedsmguy for the T-Case. But when I was coming to a stop yestarday it felt as if it was going to bog down. The rpms dropped to about 700. I had read that it could be a possible VSS issue. If it is a VSS issue I am in need of a little education here. Specifically on what it is and how to go about fixing.

I tried to search no specific answer on how to fix it other than replace the part.

Thanks in Advance

 

[Terry Posten]

Check to make sure your close throttle switch is working properly.

It is a basic "short to ground" with the throttle closed and o"open" when you just crack open the butterfly.

Use a basic ohm meter and set it to continuity check and go from the tab to a ground point on the engine (Not the throttlebody itself).

You should have "tone" when it is completely closed and no "tone" all other times.

This tests whether the TB is properly grounded and if the switch is a little sticky.

What this switch does is tells the ECU to hold idle at 1200 revs while idling down to a complete stop. Once the car is stopped, the ECU will then allow the idle to fall to whatever you have the idle set at. Stock is 800 +/- a few but some have Keydiver program a high set point for larger cams and such.

I have might set to 1000 revs at idle.

 

There are many, many different issues that can all cause stalling when coming to a stop. Do you have a logger to look at the ISC? Have you set the BISS, as per the VFAQ idle instructions? Is your timing at 5* BTDC, set with a timing light, as per the VFAQ?
One way you can check to see if the ISC and ECU are able to control the idle is to sit idling and jerk the steering wheel very quickly. If the wire is properly connected to your power steering pump, the ECU will step the idle up briefly ~100-200 rpm. Or, you can turn on the A/C and see if the idle raises, instead of dropping.

 

Thanks for the advice I will be checking it later tongight after work /ubbthreads/images/graemlins/crazy.gif

Hopefully I can have back on the road soon because I really dont want to cause unnecessary damage.