QuestionHi John.
I found a TPS for $85... cheap fix. Where is the TPS located ? Is it obvious to find?
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The text above is a follow-up to ...
-----Question-----
Hello! I'm hoping your expertise can help. I have a 1995 Discovery (automatic, gasoline). Last summer it started idling strangely. First when I would start it would rev high, and continue to do that for some time, even if I put it in drive. It was shortly after that the amber Check Engine light came on. Later I found when it was stopped at a light with it in drive, the idle would drop slowly to where it was running rough (but never stalled) and then would rev back up to normal idle after a few seconds. Finally it also began starting very rough. I took it to the dealership, and they hooked it up to the computer and checked it out. They told me my vacuum advance was bad. They also said my distributor may be bad and have to be replaced. I changed the vacuum advance myself, and also checked the distributor. It seemed fine except for a crack in the plastic shield beneath the rotor.
With the new vacuum advance the high idling has almost disappeared (still occurs rarely), but it still slowly loses rpms when at a stop while in drive (if I switch it to neutral, the revs pick up), and it still is starting rough. Basically the new vacuum advance made them occur less often, but they still occur. I also tried using some fuel system cleaner in my gas tank to see if that was possibly the problem, but it didn't seem to do much, if anything.
Am I looking at seperate problems here? What do you think my next step should be?
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Hi Curtis,
we have the same Disco...it's a real workhorse! You had better change the distributor cap (crack is bad). Most likely your TPS (throttle position sensor) is at fault. I had the same problem and for $550 the dealer fixed it. For $120 you could probably do this yourself. I know I could have...
trouble was... at the time, I did not know it was the TPS and the dealer played me like a violin: to the tune of $2500. When I went to pickup the Disco, I was not even out of the dealer's driveway when the rough idle started up again. For $550 more, they replaced the TPS and the problem was solved. Of course, I was furious. $2500 was wasted on new parts I probably did not need. THe dealer said otherwise (of course).
Best of luck,
JohnMc
AnswerHi Curtis,
a TPS for $85...nice.
Here's the LR install instructions from the workshop manual:
THROTTLE POSITION SENSOR
Service repair no - 19.22.49
Remove
1. Disconnect battery negative lead.
2. Disconnect multi-plug from harness.
3. Remove two screws securing sensor to plenum chamber and carefully pull sensor off throttle shaft.
4. Remove old gasket.
Refit
5. Fit new gasket.
6. Align sensor and shaft flats, slide sensor on to throttle shaft. Secure sensor to plenum chamber.
CAUTION: DO NOT operate throttle mechanism while throttle position sensor is loosely fitted, damage may be caused to throttle position sensor wiper track.
Curtis, if you want the actual techsheet, send me an email and I'll forward you a copy.
Regards,
JohnMc
