Hi guys, my first post to this group. Did a lot of searching and found a couple of things about rough idle problems on the 2.6 motor. I have a 91 Rodeo 2.6 that's been having a rough idle problem for quite some time now. I have taken it to a mechanic a couple of times with no fix.
I have replaced the EGR Valve, PCV Valve, checked timing, replaced spark plugs, replaced O2 sensor, etc etc. Still no fix. What is weird is that i pinched the lines from the thermal valve in both directions as a test with channel locks on both sides. When I did this the idle improved about 90% and seems to be working well, but idles high quite a bit. I imagine there is something wrong with the high idle solenoid as well but i don't see any codes or a check engine light. As a matter of fact, I have NEVER seen a check engine light with this truck, and you would think I would have by now with all the problems I'm having with hit.
I'm wondering if anyone here has replaced a thermal valve to clear this problem. If so, did it work? Are there some other things I can check? The valves seem fine within tolerances as well.
Any help would be appreciated.
Jack