Land Rover Repair: Start Engine problem Dicovery I, throttle position sensor, lab scope

Question
Is you don't mind to ask you agin?
Where is TPS located?
And I just wonder for emagency do yo not recommedn for Jump start for Discovery I?
Thank you for your kind support.
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Followup To

Question -
Dear John,
I had problem starting engine for 96-Discovery I.
I thought was security alram system first but not quiet same as when I had security armed.
Beacuse Main panel are keep fading out.
So I thought was flatten battry and I ask freinds to do jump start. Engine was start but when I was driveing ideliing level was very high and When I arrived home and checked egine was very overheated. Next day of cause engine was't start and none of light was on. So I changed to new battery but still same problem. strange click sound from inside and alram red is flashing.
Would you recommend solution?


Answer -
Hi Taka,

this could be the throttle position sensor (TPS).  It can cause this type of problem. Not very expensive but an experienced mechanic should be used to test and replace this.  If you are good with mechanics, it's possible that you could do this yourself.

Best of luck,

JohnMc

Answer
Hi Taka,

no problem.

The TPS sensor should be located behind and just above the left valve cover.  It's black hardened plastic I wish AllExperts had a photo attachment capabilty.  Just text alone is not enough!

"The TPS tells the computer that the throttle is being opened or closed to give a momentary change in fuel delivery. If the TPS has a glitch it can cause a  esitation or a jerking action. The best way to test the TPS is with a lab scope to see if there is a drop out of voltage as the sensor is moved, volt meters are not fast enough to catch most glitches. Voltage will range from about .5v with throttle closed to about 5v with throttle wide open."

Here's a webpage with a photo: http://www.roverparts.com/Parts/ERR4278.cfm

Yes, it's possible to jump start a Disco.  Just make sure that the negative cable is placed on a solid ground and NOT the negative terminal post of the battery.  You could clamp the boosting cable to the part of the engine or the frame of the Land Rover.

The sequence is ...

on the Land Rover, negative cable to ground (engine or frame), positive cable to positive terminal post.

THEN...

turn on engine of CHARGING vehicle and ...

attach positive cable to positive terminal post of CHARGING battery, then (carefully) negative cable to negative terminal post of charging vehicle.

Make sure CHARGING vehicle engine is running at the time of boosting Land Rover vehicle.  This ensures that the charging battery is itself being charged by the alternator.

Best of luck,

JohnMc