4200 throttle pot query.

[Emtee]

Well having for some time suspected I have a 'flat spot' on my throttle pot (only evident as I pull away from stationary), and having acquired a replacement from Duncan of England some time ago (used but from a much lower mileage car with same part number etc, etc), I finally got around to fitting it this afternoon.

The job itself is quite simple, just four screws / bolts involved with a further two to get the brake pedal switch out of the way to clear a bit of access, but it's an absolute dog to get to and work on, so it took more than two hours, still nevertheless I got it done, though I'll no doubt have a stiff neck in the morning!

All seemed well and other then setting off the alarm after I'd turned the battery back on (doh), the car revved perfectly whilst in neutral. I then took her for a spin and just on initially pulling away, the revs lurched quite badly, but after than all seemed well with no lurching, no flat spot and a nice clean acceleration on the pedal in all gears.

The weird thing is the car has thrown the gearbox warning light? I stopped, turned off and on again, but still have the warning light. I'll do a battery reset in the morning, but does anyone have any clues on this?

All pointers welcomed.

Thanks in advance, Em.

 

[ADM]

sorry to sound dim but what is "POT" heard it mentioned a lot on here

 

[Emtee]

sorry to sound dim but what is "POT" heard it mentioned a lot on here

Hi Andy,

Sorry should have been clearer... it's the throttle potentiometer. The 4200 is 'drive by wire' so the potentiometer sends a throttle pedal position signal to the ECU which then sets the engine variables accordingly. They come as contact potentiometers as standard (an arm rotating around a contact strip) and there is therefore the potential for the strip to wear, which is why I wanted to change mine.

Cheers, Em.

 

[philw696]

Andy,
Im sure there are a few members on here who full well know what "pot" is if you know what i mean.

 

[Emtee]

Andy,
Im sure there are a few members on here who full well know what "pot" is if you know what i mean.

Haha, I love it Phil. "Throttle Pot' is such a good name for high grade weed!

 

[philw696]

Emtree just the generation we grew up in.
Would not have my time over in any other period.
Born in the 60's
Teen's in the 70's
Parent in the 80's
Getting old and stupid from there on HAPPY DAYS.
Phil.

 

[ADM]

Hi Andy,

Sorry should have been clearer... it's the throttle potentiometer. The 4200 is 'drive by wire' so the potentiometer sends a throttle pedal position signal to the ECU which then sets the engine variables accordingly. They come as contact potentiometers as standard (an arm rotating around a contact strip) and there is therefore the potential for the strip to wear, which is why I wanted to change mine.

Cheers, Em.

Thanks Em.

 

[Emtee]

Well did a battery reset this morning and let the car idle for a good 5 minutes without touching the throttle. The reset cleared the gearbox warning light and all seemed well, so I went for a quick blat and back it came, this time accompanied by the ABS and MSP warning lights!

Not sure what's throwing them as the car seems fine. Gear engagement is as sharp as it was before and swapping out the throttle pot does seem to have had a positive effect on the acceleration.

Flummoxed.......