Jeep Throttle Body Cleaning
| Natural state - MANY years of use. Not too clean. Air filter you say... K&N washable / re-usable oil impregnated cotton pleated filter with an (K&N) oiled foam pre-filter. The trails are DUSTY things and I often take the rear spot for photos with other jeeps in the picture. In the end, do I notice a difference in performance. Maybe yes? Is the noticing actual or simply because I _should_ notice an improvement? At least it is cleaner. |
| After a few minutes with throttle body cleaner, a couple of paper towels, and a toothbrush. The hand throttle came in handy at holding the throttle plate open (it opens to about 90% - well more than it ever gets used). |
| The
Idle Air Control system - a component of the Jeep that I did not know
about. A mechanic friend educated me on the system when I was replacing
fuel & ignition system sensors and controls (the old devices kept
in the jeep as spares). The throttle plate in this jeep is manually actuated. It has a cable connection to the gas pedal. This also makes life simple to add a "hand throttle" that is used when riding on trails - a second cable to the hand throttle to open the throttle plate. Newer vehicles have electrically actuated throttle plates where the computer directly opens the throttle for how much air should be introduced to the motor. As my fuel injection system is "old-ish", the computer needs some method to control air volume into the motor when at idle. Cold motor / cold morning starts want more air / more fuel to run but when the motor is warmed up it can operate with less but the computer can't move the throttle plate position. Adjusting the amount of air into the motor, at idle, is what the IAC system does. Throttle plate closed, the computer controls how much air is introduced to the motor via the Idle Air circuit. Air travels into the green circled port, through the idle air valve and into the manifold at the yellow circled port. The idle air valve can rapidly change to adjust the amount of air to pass into the motor. On a cold morning, with this control system open more than typical, the sound is like "dry bearings" in a v-belt pulley. |
