1998 ranger issue

[rlobbe]

Hi looking for input, my 3.0 runs good, decent mileage, 25,000 miles on factory rebuilt engine.
The issue is when driving it will never go to idle either when coasting, between gears or in gear. It will never go below 1500 rpm until at a complete stop when it idles at 900 rpm.
Any thoughts ? Thanks

 

[franklin2]

Closed throttle at high rpm creates more emissions, so they hold the intake open till a certain road speed. That being said, yours is a little high, your idle speed is a little high. I think it needs adjusting, and that will lower the 1500 rpm and the 900 rpm.

1st thing to do is get the engine warmed up and idling at 900 rpm, and then start spraying some brake cleaner over the engine. If the engine idle changes, that means it's sucking in the brake cleaner into the engine and you need to address that leak.

If you can't find any vacuum leaks, the next thing to do would be to get it warm idling again, and then with it idling, unplug the idle air control solenoid. See what the idle speed does. It should slow way down. If it doesn't mark the idle stop screw on the throttle body and then turn it back till you have about 600 rpm or so. Plug the idle air control back in. Then drive it for a couple of days and see how it does. It will take a few starts and stops for the computer to relearn the new idle setting.