| Author | Message | ||
     Frederick Isaac (Freddyisaac) New Member Username: Freddyisaac Post Number: 3 Registered: 05-2003 |
Hi, In continuing to try to restore my 88RRC discovered that my TPS had bare wires on the engine side. This means a removal of the female socket on the other side of the plug from the sensor itself. I was meticulous in cutting the wires and tracking color/position. The TPS has 3 wires red, green and yellow, whereas the engine side is colored red, yellow and red/black stripe. The wiring seemed to be red - red yellow - yellow red/black - green. (oddly logical!) I disconnected the TPS and tested the resistance, seems to cleanly swing between 5.5 ohms and approx. 0 (not exactly). Nothing seems to be wrong. When I reconnected, I followed the workshop manual (which seems weird) and tested the green and yellow equivalents and got 4.83V at idle. I thought that this was supposed to be 0.33 +/- 0.03V. I did actually get 0.36V but between the yellow and red wires. Have I wired this this wrong (after all the ws manual says that the engine side colors are red, yellow and white/purple - I think). Is the manual to be trusted. After all it is only a potentiometer (i.e. two variable resistors in series). Just thought I would ask before I try to trace back to the EFI cpu itself. After all the motor starts even with the TPS disconnected and seems to run just fine. Can anyone please help! Freddy | ||
| Ian Bentley (Ibentley) New Member Username: Ibentley Post Number: 3 Registered: 06-2003 |
I'll check the wiring on my '87 tonight. If the truck is idling OK, with no EFI light on, I'd agree its probably wired correctly. The shop manual gives the pins to check at the ECU. I like to check here in any case. The wiring on these things is the smallest gauge I've ever seen used, and a break somewhere in the middle can drive you nuts. | ||
| Ian Bentley (Ibentley) New Member Username: Ibentley Post Number: 4 Registered: 06-2003 |
Checked mine this evening. The wiring is the same as yours. Red-red Yellow - Dirty white (might have been yellow once) Green - Red/green | ||
| Frederick Isaac (Freddyisaac) New Member Username: Freddyisaac Post Number: 4 Registered: 05-2003 |
Thanks Ian, I am sure that this is now correctly functioning. Should the EFI light come on if the TPS is disconnected? I think that my EFI light has been disconnected by the previous owner. In fact I think that the previous owner has disconnect most everything. Do you happen to know where the audible warning switch plugs in? I can't find it. Oh well back to the circuit diagrams. Thanks very much for your help at least I am now sure that the TPS is correctly plugged in and seems to be working ok :-) Freddy |
