throttle pedal problem :(

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1

hi everyone

I have a problem with my throttle pedal well two problems, actually…

  1. when I lift the throttle (when pressing the clutch for shifting up/down), the revs stay high or even go higher then the actual position for a few seconds. That means, when I shift in city traffic (stop&go) @3000rpm, the revs go up to 4000-5000rpm for about 1-2 seconds before going down again. When I shift in normal road use at around 6000-7500 rpm, the revs stay just in this position until I release the clutch. It feels as when I keep the throttle down while pressing the clutch.

  2. The throttle pedal feels very hard, sometimes just if only full throttle or nothing was possible. Which is a bit disturbing for sensual throttle treatment

hope that is explained understandable (more or less)?

Any ideas where to search for first?

btw. Car was @ my garage and they did a full service and ‘solved both problems’ (which I told them before)

the bill is for a full service at least

2

A number of things to try:

  1. Throttle body butterflies sticking.

  2. Throttle cable needs adjusting at throttle body end.

  3. Wheel speed sensor (rear right side hub) needs cleaning.

  4. Throttle position sensor is faulty/needs cleaning.

  5. Leaky vacuum hoses to throttle bodies (see recent posts by the Venerable Mr Bean).

Sorry, but it’s probably going to involve a process of elimination.

Bloody VHPDs, & crap mapping of Lotus ECUs don’t mix!

3

I’ve recently had throttle bodies stripped and rebuilt to get rid of similar sticking problems caused by carbon deposits inside.

4

Mr Pesky, thanks a lot for your helpful answer (as usual )

I guess it’s not the TPS again (changed it 4000km ago), but the other 4 possibilities are more than enough for havin fun at the garage

5

I’ve recently had throttle bodies stripped and rebuilt to get rid of similar sticking problems caused by carbon deposits inside.

I will start with throttle body then, I guess

6

I suffered from a “hanging throttle” recently

Bought this item
http://www.eliseparts.com/shop/index.php?main_page=product_info&products_id=607
and that cured it

It also gives you the ability to choose one of three ratios between throttle travel and throttle opening. Standard is middle one.

7
  1. Throttle body butterflies sticking.

and:
2. Throttle cable needs adjusting at throttle body end.

100 points for mr pesky

8

100 points for mr pesky

That’ll fook me licence up - anyone know a good barrister?

9

I found on my Elise and subsequently the Exige that the nyloc holding the flat pivot ‘flat’ unscrews a little and allows the pivot to twist slightly and stick.

I greased it, tightened it up and it’s now fine. For 20 notes the Eliseparts solution has got to be a good idea though - reaches for debit card…

Just my 2p

As for carbon deposites - I took the airbox and surround off recently and the insides of the TB’s were caked in crap inc the trumpats and butterflies. Gave em a good clean then a spray with carb cleaner and its noticably better.

10

thanks for that idea I’ll check this out!