I had this same problem with my 1995 Quest and ECUtalk reading 55 degrees. I hope this helps any who run into this problem.
All you have to do is change the TimingOffset parameter in the ecutalk.ini file. Using a timing light I set the timing to 15 degrees at idle. I think I needed to use -40 to get my timing to indicate 15 degrees in ECUTalk. Use what works for your vehicle and double check with the timing light.
Here is a description of the change from the ECUTalk.com web page. You need to use ECUTalk 1.3.3 or later to use this feature.
“12/05/2008 – ECUTalk v1.3.3
#14 Add offset option timing so US users can get correct timing readings. Add offset option timing so US users can get correct timing readings Eg, US users can correct timing values by applying -35 offset to timing value (as currently 50deg is shown for 15deg on many US cars).”