What would a faulty Throttle Potentiometer cause

[lakemaligne]

I drive a 1996 ,16v ,2Ltr petrol 406 .Could any one please tell me what symptoms i could expect from an intermittenlty faulty Throttle Potentiometer,and how it works,and whether or not it can be serviced or cleaned.

I have a long ongoing intermittent problem which is driving me to distraction and has been ruining what is normally a faultless car to drive. Briefly, my car for 1 or 2 days a week,decides to "jerk" as i lift off and on the throttle,coupled with a high tickover in the region of 1200rpm,until that is, the car comes to a halt, when it drops to the normal 950rpm. During this period only,If i try to pull away very smoothly ,the car "hesitates " for a split second,then as i contiue to depress the throttle ,the car powers away normally.On other occassions ,instead of ticking over too high, if i drop into neutral and roll up to a junction,the rev gauge plummets to zero and the engine nearly stalls for a second then resumes the normal 950rpm tickover.Then for no apparaent reason,every thing runs fine.

If this helps ,the fault does seem to be brought on having just been stuck in slow moving traffic jams,where a lot of crawling at low speed ,and feathering of the throttle is involve, almost as if it does not like using a certain portion/area of the TP.

Can anyone answer any of the above questions please.

[rwb]

A faulty throttle position sensor should cause an ECU error code with message "engine anti-pollution system defective".

I had mine replaced at 85k, it had a flat spot but I was not getting the warning message.

Since then, at about 150k, I started to get the warning message, but a good squirt of electrical grease has kept it quiet.

[maxxymilian]

http://www.youtube.com/results?search_q ... type=&aq=f

The tps is the most common fault for problems with cold start and poor performance when ypu start the car in the morning. The problem is that no fault code may appear in diagnostic mode and the best way to know it's working is to change it with a healthy test unit.

[tenwierdufos]

Has the 2 litre petrol got a throttle pot?

I know the HDI does as theyre drive by wire

Didnt think the petrols did though, mine is just throttle cable right onto the throttle body. Correct me if im wrong of course lol

[lakemaligne]

Tenwierdufos.
There is certainly a TP on my 2Ltr petrol 406,its mounted on the underside of the throttle housing.The throttle cable is attached to the large cam on the top of the throttle spindle,which travels down through the throttle housing and out the bottom where the TPS is mounted.

Maxxymilian,
During the cold snap my car started ok from cold,but the engine revved up and down on tickover,until i had driven it for a few miles,then the tickover would remain high as previously described during one of its episodes. My ECU is continually downloading a fault code of "Irregular fuel delivery",and the fault light appears a few times each day,but only while i am cruising,and not when the symptoms are occuring.

RWB,
Can you reccomend an electrical grease,and did you take the unit apart and squirt it inside.

[maxxymilian]

Use carborator or contact cleaner spray. Any kind will do. Also antioxidizing grease and for the connector. And don't put grease inside the tps