Tempo L4-140 2.3L HSC (1986)
G.
Install purge line tester (Tool T84T-9600-A) into the end of purge line that is still connected to the intake manifold spacer.
H.
Disconnect ISC motor from wiring harness as follows:
Simultaneously:
1.
Connect tachometer, Rotunda Model 059-00001, 099-00001 or equivalent.
2.
Start engine.
3.
Manually hold throttle above 1000 rpm.
4.
Push ISC plunger until it retracts fully.
5.
After plunger retracts, release throttle and quickly unplug the connection.
NOTE:
Before proceeding, verify that the throttle lever is resting on the speed screw and that the engine idles at specification for
anti-dieseling rpm (750 rpm in neutral).
I.
Install air cleaner assembly, but do not connect the flexible fresh air tube to the air cleaner duct and valve assembly. Using a propane
enrichment Tool T75L-9600-A or equivalent, insert the tool hose approximately 3/4 of the way into the duct and valve assembly. If
necessary, secure the hose with tape.
J.
When the above Steps have been completed, proceed to Section II.
Pages 4-93 & 4-94
1986
Carburetors, Fuel Charging Assemblies and Throttle Bodies
4-93
Idle Mixture Setting Procedures
IDLE FUEL MIXTURE-PROPANE ENRICHMENT METHOD
4.9L TRUCK UNDER 8500 GVW w/YFA-IV FB
NOTE:
This procedure is for the 4.9L engine only. It is not for trucks over 8600 GVW. Propane specifications are not listed for these applications. If
CO and HC are not within specification, perform appropriate electrical diagnostic procedure, Section 15.
I.
Vehicle Preparation
A.
Apply the parking brake and block the wheels. Disconnect the automatic brake release (if so equipped), and plug the vacuum connection.
B.
Connect an analog tachometer, Rotunda 059-000010 or an equivalent analog tachometer.
C.
Disconnect the flexible fresh air tube from the air cleaner duct or adapter. Using propane enrichment Tool T75L-9600-A or equivalent, insert
the tool hose approximately 3/4 of the way into the duct or fresh air tube. If necessary, secure the hose with tape.
D.
When the above Steps have been completed, proceed to Section II.
II. Propane Enrichment Method (Except as Noted)
NOTE:
Leave all vacuum signal hoses attached to the air cleaner assembly when relocating the assembly to perform carburetor adjustments. The air
cleaner assembly must be in place, however, when measuring engine speeds.
CAUTION: Prolonged engine idling can result in catalyst overheating and excessive underbody temperatures.
A.
Verify engine timing is set to specification-reset if necessary, Section 15.
B.
Place A/C-heat selector in the Off position and verify that all accessories (lamps, defrost, etc.) are Off.
1986
4-94
Carburetors, Fuel Charging Assemblies and Throttle Bodies
Idle Mixture Setting Procedures
