At this point I have had my 91 runner for about 6 months, and while it runs significantly better than it did when I bought it, I still seem to suffer from unusually high idle and poor fuel economy. Since purchase I hacker changed or tested o2 sensor, TPS, ignition timing, and idle speed according to FSM. my most recent discovery is that the vehicle seems to run significantly better when warm, so I went ahead and tested the EGR valve. When I apply vacuum to the valve at operating temp, I get no stumbling from thr motor as if it is about to die. Can I safely assume the EGR is bad or can this be an indicator of other problems as well?

Thanks,
Dyla