Hi all im new to this so please be easy on me,

I am currently driving a 1.9 stilo jtd active aircon (115) 54 reg.

a few weeks ago i lost all gas on my accelerator. I noticed the engine was stuck in a constant low rev as i was able to use clutch control to get through the gears and sit in 5th gear at 40 MPH.

1st gear gives me 8 MPH

2nd gives me 20 MPH

3rd 25 MPH

4th 30

5th 40.


I took it to a garage and the reader said:

P0120 accelerator position sensor (1).

the garage tried clearing the error with no luck.

I replaced the MAP sensor on the car the same day with one from the scrapyard. After replacing i still had the issue.

the next day i took it a run and did a throttle relearn (ignition off, on, idle, off, on) and this seems to have helped. the issue disappeared completely for around 100 miles or so, then came back. however it didnt stay this time. I took it to garage for 2nd tim and they managed to clear the error off the ecu. what I get now is for every 3 or 4 hours of driving i do in total it will happen for about 5 minutes, after which it will go back to normal. I had it back in the garage a third time and they investigated and couldn't find anything wrong. no faults or lights or anything.

Im pulling my hair out on this one as I would like to get the issue fixed. My fiance is a new driver and I dont want her to feel more nervous than she already is. Any help would be greatly appreciated.

Kind Regards,

Calum

Check your brake switch re-set it.

P0120 = Throttle Pedal Position Sensor/Switch A Circuit Malfunction.

The throttle pedal position sensor is a potentiometer at the top of the accelerator pedal. There are two of them (A and B) working in tandem.

Diagnosis by substitution will be expensive, so can't imagine why you would replace the MAP sensor.

Get your garage to test the potentiometers and the wiring and connectors between the potentiometers and the engine management ECU.

I'm positive I had a similar problem, when you start it up dose it idle normal or is it high?

When mine was poor it was the egr valve that was blocked solid, and making errors, worth while giving it a clean?

Davren said:

P0120 = Throttle Pedal Position Sensor/Switch A Circuit Malfunction.

The throttle pedal position sensor is a potentiometer at the top of the accelerator pedal. There are two of them (A and B) working in tandem.

Diagnosis by substitution will be expensive, so can't imagine why you would replace the MAP sensor.

Get your garage to test the potentiometers and the wiring and connectors between the potentiometers and the engine management ECU.

Click to expand...

I replaced the map on the advice of garage
For some reason it made an improvement. Going to take it to an auto electrician if I can. When the issue is there sitting at idle there is a small revving. When issue goes away the revving at idle returns to normal. I mentioned egr to garage but they were doubtful as there isn't any smoke. I don't even get any warning lights lol

calummitchell said:

I don't even get any warning lights lol

Click to expand...

The 8 valve JTD engine management ECU sometimes records a fault code for a blocked EGR valve, but doesn't trigger the warning lamp.

The 16 valve JTD engine records a fault code and triggers the warning lamp.
.

Davren said:

The 8 valve JTD engine management ECU sometimes records a fault code for a blocked EGR valve, but doesn't trigger the warning lamp.

The 16 valve JTD engine records a fault code and triggers the warning lamp.
.

Click to expand...

The fault reader didn't even say anything about the egr valve:S concerned about the cost of fixing this XD