kevco

I just bought an 87 pathfinder 4x4 from my brother. He has had it for some time and its always been fine. I have even driven it while he owned it and it functioned properly. It sat for about a year before I bought it because it was an extra car. Now it seems to run too cool and the temp gauge never goes over 1/4. heater works fair I suppose but I feel it could be hotter. The real problem though is the idle speed. It is a v6 and the idle has never dropped below 1100rpm. when started initially it runs at 2000rpm for awhile and never seems to drop enough, even when driving on the freeway over 1/2 an hour. I live in southern CA and at night right now the coldest it gets is about 35degrees F, so its not freezing cold or anything. I dont know how engine temp affects rpm. so I bought a thermostat and plan on replacing that this weekend, even though I heard it was difficult. I was just wondering if there was a tps that could be bad or some other injection component I should be looking at. I'm not that familiar with fuel injection. thanks for any help.