eksine

Maybe the power steering sensor is broken even though the wire looks good. Not sure if theres a test for it. If there isnt you'll have to replace it to know for sure, ebay probably has some used ones. If lpg isnt propane I dont know what that is. Id still suspect idle air control valve than no matter how sure you think you are, even if thats not it, I dont know if you and the other guy just have similiar problems or if you two are the same person but he said he replaced his long block. In both cases you both say all sensors are checked and work ok, you guys still have the problem. If all your guy's sensors work right and there are no vacuum leaks and the ecu works right than you cannot have this problem. I'm trying to state the obvious, you cannot have fully functioning electronics and stuff and still have this problem. Either you guy's tested something wrong or you'll need to think way outside of the box. Like its been mentioned your electronics may be working fine but an intermittent problem suggests a periodic leak or break on a connection or a missing ground wire or a failing microswitch or your ecu fails at random times or some other witchcraft. The only ways to test for those is to do it my crazy way and replace every part, it makes no logical sense to you but to me diagnosing for years and years with no result makes no sense to me.

kslavek

Every electrical crap works perfectly well in this car... I am 100% sure now.
The problem is with some mechanical part(s). Throttle, IACV, driveshafts, transmission, engine mounts and every rubber part of the suspension. Maybe all of them in some way. Easiest way is to change the whole intake manifold from a good working car as a first step. I have not much time left.
Next: engine mounts (ALL not the one in front)
Next: front suspension
Last: transmission and differential play
Now in my case I have additional prloblem - gas (or cruise control...) cord is getting stuck when hot, I need to lift gas pedal to lower the rpm. Or maybe its the throttle, I dont know for sure at this moment. It affects traffic jam ride a lot.