Regal V6-173 2.8L (1988)
^
Check for proper T.V. cable adjustment.
^
Is there tension on the T.V. cable when being pulled and being released with engine off?
-
If the T.V. system fails this test, it could be caused by a disconnected throttle lever to cable link, a stuck T.V. plunger in the T.V. bushing or a
broken T.V. cable.
^
If the T.V. cable has tension when the engine is off, but goes slack when the engine is started, the T.V. plunger is being pulled into the bushing
because the T.V. plunger that reduces accelerator pedal effort is receiving too much pressure.
-
The throttle valve (Figure 1, Item 311) may be sticking or stuck in the bore. This could be caused by sediment. The valve must move freely in
the bore. Clean the valve and bore so the valve moves freely in the bore.
NOTICE:
Excessive lapping of the valves for a Hydra-Matic 4T60 (THM 440T4) may cause the valves to stick. Too much lapping can take the sharp cleaning
edge off the valve land. Sediment can now wedge between the valve land and bore, causing the valve to stick. Also, the lapping material can impregnate
into the valve lands, causing the valve bore to excessively wear. This will cause the valves to stick unless the valves are lightly lapped, then cleaned in an
ultrasonic parts cleaner to prevent bore wear.
-
If the throttle valve moves freely in the bore, then the pump cover is missing the machining of the throttle valve (Figure 1, Item 311) exhaust.
^
Check the governor system for a rise in pressure of approximately 1 PSI (6.895 kPa) for every MPH (1.6093 km/h) when a pressure gauge is
connected to the governor pressure tap.
IMPORTANT:
Some "rules of thumb" for governor pressure: - At 0 MPH (O km/h) the pressure will be about 0 - 4 PSI (O - 27.58 kPa), depending on the model. -
Below 30 MPH (48 km/h) the pressure in PSI will be at or below the MPH reading by as much as 6 PSI (41.37 kPa); above 30 MPH (48 km/h) the
pressure in PSI (kPa) will be at or somewhere above the MPH reading by as much as 20 PSI (137.9 kPa). - The reading for a cold transaxle and hot
transaxle should be about the same; if not, then orifice # 5 - a slot in the accumulator cover gasket - may be clogged or the governor assembly could be
leaking. Orifice # 5 temperature compensates the flow needs in the governor circuit. Also, the accumulator cover to case bolts could be loose, causing the
cold governor pressure reading to be much higher than the hot governor pressure reading. This would allow 4th gear when cold and no 4th gear when
hot. A clogged governor screen that is in the case will cause early upshifts and not delayed upshifts.
The rule of thumb is that governor pressure will increase with MPH (km/h).
Figure 1 - T.V. Plunger/Bushing And Throttle Valve
SERVICE PROCEDURE:
If during the diagnosis of the T.V. and governor system it is found that the T.V. plunger/bushing assembly is worn/sticking/ binding, replace the
assembly with the parts listed below in SERVICE PARTS INFORMATION.
SERVICE MANUAL REFERENCE:
See the 1984-90 Service Manual for repair procedures.
