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-   -   Accelerator Pedal becoming stiff / sticky (https://www.team-bhp.com/forum/technical-stuff/154737-accelerator-pedal-becoming-stiff-sticky.html)

I'm facing a weird issue in my 2006 swift Vxi (petrol). What happens is, while driving, I notice that the accelerator pedal becomes hard (requires more force than usual to press). Then, after releasing the pedal, the engine races before coming back to the regular RPM. The issue is really hard to reproduce since it occurs randomly. This has been happening for a while now. Not sure if it is mechanical or electrical in origin, but if I shut the car off and switch on again the issue disappears. I reported it at the last service and was advised a throttle body cleaning, but the issue persists. The car is around 8 years old now, with 106000 km on the odo. Regularly maintained and used, no other significant issues. Any guesses what this could be?

Hi Ajitkommini,

Suggest looking at the following items:

• Accelerator cable - With age, this cable may have lost its internal lubrication. This item fails rarely since the internal lubrication is pretty good to start with.
• Throttle Position Sensor (TPS) - This sensor is mounted on the Throttle Body and some gunk buildup could have reduced its effectiveness. Could be due to a loose or cut sensor wire too.
• Throttle Body - With usage, the butterfly valve in the Throttle Body accumulates dust mixed with fuel, making it a bit sticky. Even if it is not sticky, cleaning the butterfly valve will improve throttle response.

A change of throttle cable should fix this, the cable is sticking somewhere.

Thanks for your replies.

I got the throttle body cleaned during the 105000 km service earlier this month. I guess they would have cleaned any gunk deposited, and also the butterfly valve etc. I will ask them to check the accelerator cable and the position sensor though.

@ajitkommini:Throttle body problems are well manifested during idling(rough idling,rpm fluctuations etc).It is good to get the TB cleaned during a routine of 20k kms.

I feel the real culprit here is the accelerator cable or the "C" shape where it gets attached to. Kindly get it checked and lubricated.

Its 99% the accelerator cable. Get it changed.

Hi, I am facing the same issue (both in neutral & while driving) since today morning in my Zen 1999 (Carb Model). Would it be the same cable issue? I just had the vehicle checked 2 days ago at the local garage for clutch shudder and unusually high vibration in neutral. And now this problem!

Actually the problem seems to have gone away after the throttle body cleaning. I was under the impression this had been done during the last service but somehow it was missed. Once done this issue hasn't reappeared. I did have them order a new accelerator cable anyway in case it happens again.

I would never just start replacing parts, unless replacing a part is substantial cheaper and quicker then a proper diagnosis. Even on relatively, seemly simple problems I have found it always pays to check things out in a systematic way and don't jump to conclussion. If you do, you might end up replacing parts without fixing the problem.

In this particular case, I'm not familiar with your car but here is how would go about it:

First start with looking in the footwell if there is anything obvious that can cause the accelerator pedal to become blocked or prevent it from moving freely. A floormat, a left shoe. Sometimes wires work themselve loose and start dangling down on to the pedals. The accelerator pedal itself will have some sort of pivot point around which it swings. Nothing wrapped around it? Say the wires or someting else?

Feel the pedal. Move it up and down. Most pedals can be moved upward a bit. If that feels very stiff, you might have found the culprit.

You might want to undo the cable from the accelerator pedal to double check. You need to do that for the next step anyway.

When checking cables, such as accelerator cables or clutch cables the best thing to do is to undo them on both ends and see if the inner cable slides smoothly in and out. If it doesn't, check for odd bends or something that might have damaged it. (I once had a case where the accelerator cable got caught in the locking mechanism of the hood.

Only once you have established that indeed the inner cable seems to to tight and there are no other external factors you should replace the cable. If the inner cable does move smoothly you move on to the next component, which is probably the throttlebody with maybe a few linkage. Again, you need to make sure the linkages and such work smooothly. So move them around and feel how smooth they move about, is there any stickyness to be felt?

You need to determine if there is gunk inside the TB preventing from working smoothly, or simple a case of some other mechanical problem o or near the TB.

On carburator engines there are usually more linkages involved, and again you need to check/verify they all move freely. Usually, you can disconnect these linkages easily and check if they move freely.

All the above checks can be completed on most cars/engines in well under 10minutes by a competent mechanic and some very basic tools.

You might also take a slightly different approach on either TB or carburators engine. If you believe (for whatever the reason) you can of course take whatever parts are in your way and peek inside. If it's very dirty you need to clean it, but it is no guarantee that was the problem. But if it is you might have saved yourself some time. On some cars/engine, say my Jaguar its quite a job to take everything off before I can actually peek inside the TB. Might be 30-45 minutes of spanner work.

All the other checks I mentioned are easily done without any major work

Just replacing parts is the so called trial and error method. Make sure you understand and diagnose the problem, and therefor fidn the correct solution, first.

I'm glad to hear the problem appears to be solved.

Jeroen

Thanks Jeroen, Will follow through your advice & revert. The pedal does move a bit and there is nothing blocking the mechanism in the footwell. I also oiled the springs of the pivot point. It appeared rusted, though not very badly :eek: Hope this rusted spring is not a big deal.

@ Mods: Sorry for the back-to back posts.

Thanks Jeroen, problem solved, the local garage had a look and rectified the cable linkage with the carb. Photo below. The cable had slipped out of the slot. Anyway I never bothered to open the bonnet :D, wouldn't have made a difference to a noob like me

Thanks for the feedback. Excellent example to show the need for good diagnostics before starting to rip and replace!
Jeroen

Hi all,

I have a strange issue with my 2008 Maruti Swift ZXi.
In the mornings, which I start the car first time, the accelerator has a strange issue. For first few 1-2 kms , the raise seems to "stick" for sometime (forgive not knowing perfect technical term here) even though I have let go of the pedal. This happens multiple times. I have switch the car off for few mins again, after which it seems to disappear. And doesn't happen again throughout the day.

I had the car service after I found this issue. The issue was not seen again for month after which it seems to have resurfaced again.

I took it back to Pratham Motors, but the advisor was clueless. He asked me to drop the vehicle at the service centre for overnight so that it can be checked first thing in the morning. But that will cause issues for me.

So thought of bringing it up here, just in case folks have some thoughts or suggestions for something which can be quickly checked when it happens.

The issue seems trivial but is scary when it happens :)

Hope its not some rat or something :) ?

Thanks!

I feel that it's the accelerator cable that has got clogged due to dirt or something and gets stuck at a place in morning. And after using the accelerator for some time, the friction causes it to get relatively free and you don't come across it again till next morning. See your service log if they've changed the cable or not.

Hmm.

Can cold weather be doing something ? Although Bengaluru is not that cold....