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1990 Dodge Spirit Question: will not idle

 

Question

bobclev, Spokane, WA, April 25, 2011, 21:21
 Rookie

my car will start fine but dies as it idles down after starting unless i feather the heck out of the throttle to keep the idle high but still wants to die. as soon as i take my foot off the throttle it does die. so far i have changed the fuel pump and sock, fuel filter, timing belt, idle air control motor, idle position sensor, EGR valve, checked all vacum lines, and removed and cleaned the throttle body. what else is there ? it starts fine every time but dies. It shows no codes other than 12 and 55 witch is normal. some one out there give me some help PLEASE

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  • Answer #1

    Johnny Mopar April 28, 2011, 11:31
     Master

    Cleaning the throttle body is sometime not enough on these older vehicles. There is a procedure to reset the minimum air flow through the throttle body, by using a metered oriface in the PCV hose, the plug removed from the throttle body throttle stop screw and adjusted accordingly. The IAC motor must have an O-ring installed for proper operation. Also the MAP sensor (Manifold Absolute Pressure) is key to proper fuel mixture.

    Minimum Air Flow test is as follows:
    With vehicle in PARK for A/T, or NEUTRAL for M/T, START engine and warm until cooling fan cycles ON and OFF at least once. STOP engine.
    START engine and ensure basic timing is set to 12°BTDC. STOP engine and reconnect coolant temperature sensor wire. Disconnect PCV valve hose from PCV valve and attach tool No. 6457 or equivalent (.125 inch orifice in attached hose) to PCV nipple. Disconnect the 3/16" idle purge hose from the throttle body nipple and plug the nipple. Minimum Air Flow Tool 6457 Connect DRB II or equivalent scanner, then START engine and allow to idle for at least 1 minute. Using DRB II, access Min. Airflow Idle Speed (if using other scan tool refer to manufacturers instructions to access Min. Airflow Test). The following should occur: AIS motor will fully close. Idle spark advance will become fixed. Idle fuel will become enriched. Engine rpm will be displayed on diagnostic read-out tool in units of rpm x 10. For example, display 95 equals 95 x 10 which indicates 950 rpm. Check idle rpm. If idle rpm is within 750-950 rpm then throttle body minimum air flow is satisfactory. If idle rpm is not as specified, clean throttle body and retest minimum air flow. STOP engine, then remove tool No. 6457 or equivalent (orifice) from PCV nipple and install PCV valve. Unplug the purge nipple and connect the purge hose. If the Minimum Air flow is not within spec's the throttle body is supposed to be replaced, however as I mentioned above, simply remove the plug at the throttle stop screw and adjust as required (usually 1/8-1/4 turn max). Reinstall plug when completed.

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    bobclev, April 28, 2011, 21:28
     Rookie

    car will not idle to perform the those tests or actions

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