Hi;
1994 Toyota 4Runner. I have some concern that the timing under control of the ECM is not working, or not working as it should.For instance, if, after setting the timeing to 8 degrees using the jumper, I then remove the jumper, the timing should read 10 degrees at 800rpm, which it does.
I believe that you should then be able to rotate the distributor away from its correct setting 10-20 degrees and have the timing hold correctly. After all, is that not the point of ECM control.
I remember my brother asking how he could set the timing on his Audii. He said he could rotate the distributor cap 180 degrees and not affect the timing. Apparently he did not know how to do the equivelant of using the jumper as Toyota does, in order to disable ECM control. The reason I'm even looking at this question, is this.
If I set timing by the book, I pass Californica Dynamic Smog testing very nicely... lots of margin on all tests, better than "average". However my power and mileage are hurt significantly with this setting.. something like 11mpg. If I advance the timing to 20 degrees, my mileage jumps to 15mpg, and power is very good.
Advancing the ignition leans the engine, which means it runs hot, I believe, although water temperature stays steady at normal under all running conditions, no sign of overheating, knocking or any other symptom. But given the history of HG problems, I do not want to leave this problem unsolved.
I've had the truck for less than a month, so little personal history with it, although I've a long history with the 22RE engine on my SR5, knowledge on the V6 is limited to a lot of reading of this board.
The only troubleshooting I've done so far is to verifty the TPS function.
Any thoughts would be welcome. Richard Harper Morgan Hill, CA