no prob. i think it the sending unit, but i will check into it. this prob just presented and tho the idle seems low that is not the idle when in park. in park and neutral it s higher, just above 500. as i said it is running well. it is higher when cold also. i got a number of parts working including temp sensor in air filter and ccv vacuum. i cant remember the name but it has a system that switches things around when hot and , i believe drops the idle then.
thanks, i listen to all suggestions and yours is on my list to check further. i am determined to get this right. it was owned by a mechanic previously and i think the insides of enginewere maintained.
That is a typical observation of the tach in the instrument cluster on an XJ. It wasn’t intended for diagnostic use. When the tach needle is just below the “500” mark in the instrument cluster a scan tool will usually display 650 RPMs.
I have replaced so many Mopar oil pressure sending units that I don’t bother to test the actual oil pressure. I am convinced the only purpose for the oil pressure gauge is to inform the driver when the sending unit fails. The few that have an actual oil pressure problem will usually drive until the engine seizes.
thanks for the reinforcement Nevada. the fact that it is running so much better now made me believe the same thing
thank you too mountain, your input is appreciated and its obvious that you care deeply for others. I will keep an eye on it. the fact that the oil is still clean after 2 months led me to believe the inside was fairly good. it would be easy to pull that ccv tube, feel vacuum and never think to check.grommet for years and when I cleaned temp sensor in air filter housing I believe vacuum motor (venture?) in the fresh air intake behind grill began to function again.
and as soon as I touch the gas pedal the pressure immediately read 20 again