| Author | Message | ||
     David Turner New User Username: silver_spur Post Number: 3 Registered: 11-2006 |
my 20,000 series spur has no kickdown i have free throttle movement all the way to full throttle, no carpet restriction under the pedal,vacuum is good and tight connectios at the manifold and the modulator but no kickdown, i suspect the modulator but i am not getting any smoke from the engine burning transmission oil so i presume the diaphragm is intact. is there any test for the kickdown system? thanks dave | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1445 Registered: 4-2003 |
Do not suspect the modulator as it does not control the (electric) kickdown. The button below the throttle pedal has nothing to do with kickdown either. Kickdown is controlled by the throttle position switch (TPS) attached to the throttle spindle on the side of the plenum chamber. The TPS actuates the kickdown solenoid located just inside the transmission. see: http://rrtechnical.info/sz/sz87/b2.pdf It describes the TPS, and the wiring diagramme on Page B2-13 clearly shows the TPS and kickdown solenoid. To test the system, first check that the kickdown solenoid is connected and that the fuse is alright. The solenoid electrical connection is located on the left hand side of the transmission casing just above the sump line. see T15 of http://rrtechnical.info/autotransmissions/sz/tsd4700_t1_to_t17.pdf If the solenoid electrical plug is found to be connected and the fuse is OK, you may test the system further by connecting a 12V bulb or a meter between the solenoid connection and the chassis. With the ignition turned on, open the throttle fully. The lamp should light up or 12V should read on the meter. If OK and the kickdown does not work, then the transmission sump may be removed for access to replace the solenoid. A solenoid is available at any transmission shop or GM parts department. A solenoid is cheaper than a transmission sump gasket at most shops. It can wait until the next transmission service. If the bulb fails to illuminate, then further system checks are required: linkage adjustment, wiring or TPS adjustment may be required, but malfunctions there are usually only as a result of defective repairs or maintenance. If the throttle position sensor fails to respond to adjustment and is found to be defective, then a replacement is a Bosch 0 280 120 300, AC Delco 213-2737, KEM 141-828, STANDARD TH98, or Beck/Arnley 158-0486. These are available at a tuning shop or at a Bosch outlet for example. RT. | ||
| David Turner New User Username: silver_spur Post Number: 4 Registered: 11-2006 |
many thanks for the info Richard,i am off to the garage Dave | ||
| David Turner New User Username: silver_spur Post Number: 5 Registered: 11-2006 |
throttle switch does not cooperate,power goes in but none comes out bridging the wires causes the relay to activate. adjusting the switch produces no result so its off shopping for a new one, once again many thanks Richard best regards dave | ||
| David Turner New User Username: silver_spur Post Number: 6 Registered: 11-2006 |
Update. After fiddling out the two very difficult screws i then removed the cover and tested the switch with an ohm meter.The results were intermittent but after some poking around i found bad solder joints on 3 of the 4 connections inside the switch. resoldering (all 4) has restored reliable opperations,after refitting and adjusting kickdown is restored Dave |
