E 250 Van L6-300 4.9L (1984)
Idle Speed: Customer Interest
Carburetor - Rough Engine Idle
Article No. 85-16-22
IDLE - ROUGH (4.9L) - VEHICLES UNDER 8500 LBS. GVW
LIGHT TRUCK 1984-85 E, F SERIES, BRONCO
CALIBRATIONS: 4-51 D, E, F, H, K, L, R, S, T, Z 4-52G, L, R, S, T, W 5-51D, E, F, H, K, L, V, Z 5-52E, F, H, K, M, W, Y
WARNING:
This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and
could create liability under applicable federal or local laws.
A rough idle could be due to a variety of conditions. Diagnostic procedures for this concern are:
1.
Ensure that initial timing is to specification and that no vacuum leak exists.
2.
Ensure that curb idle is to specification. If the curb idle speed is out of specification by more than 50 RPM, refer to Emission Diagnostic Manual
(Volume H), for reset procedure of the idle speed control motor.
3.
Inspect the fuel inlet needle. If it is damaged or if the tip material is black, install the latest design fuel inlet needle and seat assembly
E4PZ-9564-A. The new needle, which has a pink tip, is resistant to alcohol and contaminated fuel.
4.
Reset the float level as described on Page 24-06-6 of the 1985 Light Truck Shop Manual. However, for vehicles that consistently operate above
2000 feet altitude, use a 0.810 inch float level gauge instead of the 0.780 gauge specified. A 13/16 inch drill can be used as a float level gauge
above 2000 feet altitude, and a 25/32 inch drill can be used at lower altitudes. When using a drill, be careful to measure only to the identation on
the float.
5.
If the above steps do not resolve the concern, reset the idle mixture using the propane enrichment method outlined in TSB 85-1-23. However, if a
reset is necessary (Step IIE of the TSB), use a reset of 10 RPM instead of the 30 RPM specified.
PART NUMBER
PART NAME
CLASS
E4PZ-9564-A
Fuel Inlet Needle
A
OTHER APPLICABLE ARTICLES: 84-7-13
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9564A85
TIME:
1.1 Hrs. Bronco, F-Series 1.4 Hrs. E-Series DLR. CODING: Basic Part No. 9564 - Code: 94
