| Forum Home | ||||
| PC World Chat | ||||
| Thread ID: 103000 | 2009-09-09 03:06:00 | TPS Unit (Automatic Transmission) | ronyville (10611) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 808147 | 2009-09-09 03:06:00 | Hi all, I Have a Mazda 323 1994 model and a transmission test carried out by Gearbox Factory showed that my TPS unit needs replacing. Unfortunately the car is too old to buy a new one so been advised to look for a second hand one. Anyone knows where I can source one of these besides the wreckers. Thanks |
ronyville (10611) | ||
| 808148 | 2009-09-09 05:08:00 | Why not take yours apart and clean it . I do this all the time . Use a soft-gum eraser and do NOT use electrical spray cleaners! They will take the carbon resistor off the pheno-type background and you will then never know if Bob's your uncle . I'll check my US suppliers and see if they are available though . <edit> $109 . 99 USD - 2-year warranty Part Number: TPS260 |
SurferJoe46 (51) | ||
| 808149 | 2009-09-09 05:17:00 | What's a TPS unit. Do all automatic boxes have it and what does it do? | tut (12033) | ||
| 808150 | 2009-09-09 05:19:00 | It's a Throttle Position Sensor that tells the ECM just how far the driver has pressed the throttle down. It is a resistive 5VDC feedback circuit that usually will NOT make the CEL come on since wherever the driver puts his foot is OK with the ECM and it just modifies the performance accordingly. If - however it cannot return to base position, it CAN make the CEL or SES light come on since it is not correctly reporting the closed position correctly. It may also not be able to "see" the WOT or Clear-Flood position either. |
SurferJoe46 (51) | ||
| 808151 | 2009-09-09 08:13:00 | Thanks for your input Joe but my car maintenance skills are next to nothing. I can do the basics such as replacing a flat tyre and checking/topping up oils levels etc. Opening up a component is beyond my can-do skills. Will keep looking at the moment. | ronyville (10611) | ||
| 808152 | 2009-09-09 08:45:00 | I recall doing a voltage test with my multi meter on mine (SR20DE Nissan engine) to see if it's in spec at about 0.5v between the feed/signal wire and ground (I think). I think it can be rotated slightly to adjust. It probably senses the vacuum readings? | kahawai chaser (3545) | ||
| 808153 | 2009-09-09 09:25:00 | You could try Repco and see if they are are able to get what you are looking for. | convair (13650) | ||
| 808154 | 2009-09-09 10:02:00 | I get my new parts from sta parts NZ (http://www.staparts.co.nz/)- they have cheap new parts, including unlisted items on their website. You might need the engine serial number and size, and can get parts couried... | kahawai chaser (3545) | ||
| 808155 | 2009-09-09 17:01:00 | The TPS is a potentiometer of sorts - it just uses a film resistor and a brass brush to drag along the surface that indicates the "volume" of the throttle, that's all . Some are mounted at the throttle body, but other newer versions are inside the passenger's compartment to keep it in a less hazardous environment . The lattrer is considered "drive-by-wire" and there is no physical connection from the throttle pedal to the intake air control by cables, rods or other linkage . The throttle is actually opened by servos and the very newest has little to no lag-time . Older ones had a pretty large delay that could keep the engine at idle for longer than the driver's input needs and created a lot of concern - hence it was greatly improved . Use of intake vacuum is 1) old fashioned 2) not for the transmissoin much any more really . Vacuum is an engine control measurement for the MAP or BMAP device(s) that combined with the MAF (if it uses one, that is) can tell the ECM to use one program or another to operate the engine at maximum efficiency while also taking into consideration the emissions and driveability at the same time . The MAP/BMAP are basically piezoelectric generators, but the MAF is usually a fine-wire device that senses air flow and air density by the air molecules flowing over the heated filament, changing the resistance and the ECM compensates very very quickly . This value combined with the altitude sensor and the air temperature measurement control the furl:air ration when altitude changes are made and varying air density from meteorological changes take effect - it's THAT sensitive! The days of automatic transmission receiving inout from a throttle cable or a vacuum modulator are all but gone as every command to it now comes from the ECM or the TCM to asure the best shift points and performance options through multitudes of library entries in the ROM of the controlling computer . |
SurferJoe46 (51) | ||
| 808156 | 2009-09-09 17:06:00 | I recall doing a voltage test with my multi meter on mine (SR20DE Nissan engine) to see if it's in spec at about 0.5v between the feed/signal wire and ground (I think). I think it can be rotated slightly to adjust. It probably senses the vacuum readings? Please use a DVM and not an analog multi-meter. You can load the ECM down and fry it's innards with the high flow of electrons that are required to drive an analog needle. The feed wire (Base-þ) should be 5VDC, not .5VDC. This is the reference signal voltage that all sensor and active measurement devices in the ECM system use for their comparison values. You can use the output leg of the TPS and read it's voltage when you are adjusting it, but mostly nowadays, TPSs are not adjustable. All three-wire devices use the 5VDC reference wire. PS: Don't even THINK of using that small screw to adjust the throttle opening for idle adjustment! It is factory-set and is not to be moved. |
SurferJoe46 (51) | ||
| 1 2 | |||||