Hi all,

I’ve lived a weird problem with the accelerator on my 2003 TL LS since coming to own it in 2007 and I think its finally about time I did something.

The problem is this: under normal driving conditions (by which I mean just pottering about in the suburbs) as long as I don’t suddenly floor the pedal, there is no problem at all. The cable/pedal feels absolutely normal with no hint of play or friction or notchiness at any point in its travel.

But if I floor it (such as when overtaking) the accelerator cable/pedal develops what I can only describe as a notchy point (or point of high resistance or obstruction) at about the 1/3 mark on the way down. I’ve noticed this tends to last for about the next 5-10 minutes of driving before it gradually returns to normal (unless I happen to floor the pedal again). When this happens, it feels normal as I press down on the pedal till about 1/3 the way and then a very noticeable amount of resistance that I must overcome by pressing quite hard on the pedal if I want it go down further. As I said I’ve had this since the day I bought the car but it is slowly driving me mad. I had the service dept at one of the Mitsubishi dealers in Sydney have a look at it (explained it in detail to them) when I had the t-belt changed at 100,000km and they said they cleaned up the throttle body but the problem persists, no difference at all. That was 2 yrs ago.

I noticed one more thing on the weekend when I was experimenting with it. My past experience has always been that the pedal returns to normal on its own after about 5-10mins of gentle driving. But sitting in my car while stationary I’ve also now found that when I provoke the problem by flooring the pedal I can make it return to normal immediately just by turning off the engine. I don’t even need to restart the engine, that stiff resistance felt in the pedal on its way down immediately disappears (and if I then start her up again she’s still good until the next time I floor the pedal).

So, I was just wondering (I did do a search and found a thread dealing with a sticky accelerator but symptoms were different) if anyone has ever experienced anything like this on their 3rd gen Magna/Verada and if anyone has any suggestions as to what might be causing this / where I should be looking to fix it.

Cheers,
Aj

Could be one of 2 things -

Seized accell cable (however this tends to be sticky at the bottom) or sticky throttle body.

Get some carby cleaner sprayed on a rag, hold open the throttle body butterfly and wipe it clean - See if this helps your problem at all.

My KJ has this problem occasionally. When it does it all I do is quickly press it up and down (not all the way, just a small bit) gently 4-5 times in a few seconds to un-jam it and it goes away.

It got quite bad a while ago and I cleaned the TB and sprayed it with WD40 and it fixed it for about a year. Dont know whether WD40 is recommended to be sprayed there but it "fixed" it.

Could be one of 2 things -

Seized accell cable (however this tends to be sticky at the bottom) or sticky throttle body.

Get some carby cleaner sprayed on a rag, hold open the throttle body butterfly and wipe it clean - See if this helps your problem at all.

Appreciate the reply and what you've suggested but my thinking is that its something more than just a seized cable or buildup on the throttle body butterfly.

Reason I say that is the resistance or sticky point in the downward travel of the pedal disappears immediately if I turn the engine off; but if I let the engine continue running the problem continues for a good 5-10mins before gradually disappearing. This behaviour is inconsistent with just a seized cable or buildup on the throttle body butterfly.

I am more inclined to think its one of those vacuum or electrically operated actuators that work the throttle (perhaps cruise control related or maybe one that increases engine idle speed when the air-con is turned on) that's causing it, given that the symptom immediately disappears when the engine is turned off but not otherwise.

My KJ has this problem occasionally. When it does it all I do is quickly press it up and down (not all the way, just a small bit) gently 4-5 times in a few seconds to un-jam it and it goes away.

It got quite bad a while ago and I cleaned the TB and sprayed it with WD40 and it fixed it for about a year. Dont know whether WD40 is recommended to be sprayed there but it "fixed" it.

Thanks, that's exactly what I have too - if I quickly press the pedal a few times it seems to quicken the un-jamming process but not by a lot :)

Could I just ask which components did you spray with WD40 and did you just spray liberally/indiscriminately or did you target a specific area? Because that's what I'm thinking of trying now myself. Did you have to remove the plenum to gain access?

Cheers,
Aj

Try cleaning the TB.. I wouldnt use WD40.. Use carby cleaner..

Try cleaning the TB.. I wouldnt use WD40.. Use carby cleaner..

Thanks, appreciate the suggestion, only problem is the behaviour I'm experiencing is (I feel) inconsistent with just dirt on the inside of the throttle body (the symptom immediately disappears when the engine is turned off but not otherwise). Besides, as mentioned in my original post I have had the TB cleaned previously and it didn't make the slightest difference.

Are there other components related to the throttle body (or on it) that might be not working as freely as they should be due to accumulated dirt and which I could try cleaning? Anything I need to be careful about when cleaning the cable to TB butterfly linkages and related parts?

Cheers,
Aj

When engine is off there is going to be less resistance on the TB too.

Maybe its time to look at the cable.. Very common on magna to dry out and need replacing.

Appreciate the reply and what you've suggested but my thinking is that its something more than just a seized cable or buildup on the throttle body butterfly.

Reason I say that is the resistance or sticky point in the downward travel of the pedal disappears immediately if I turn the engine off; but if I let the engine continue running the problem continues for a good 5-10mins before gradually disappearing. This behaviour is inconsistent with just a seized cable or buildup on the throttle body butterfly.

I am more inclined to think its one of those vacuum or electrically operated actuators that work the throttle (perhaps cruise control related or maybe one that increases engine idle speed when the air-con is turned on) that's causing it, given that the symptom immediately disappears when the engine is turned off but not otherwise.

This is perfectly consistant with a gummed up TB. The gum, or sludge, oil or what ever you want to call it, when cold is very sticky. As it heats up it gets worse

If you have TCL this will be far worse as the butterfly is not attached to the throttle shaft as they are on the non tcl models

It will not hurt and in fact should be done at services, if you get yourself a tin of the nulon TB and upper engine foaming cleaner, give it a good clean and you may actually be surprised

If you have TCL this will be far worse as the butterfly is not attached to the throttle shaft as they are on the non tcl models

Thanks - yes I do have TCL on my TL LS and so what you've said is of particular relevance. I was unaware that having TCL meant the butterfly is not directly attached to the throttle shaft. I have a feeling my problem is somehow related to this (see comment further below) or something else connected to the throttle shaft.


This is perfectly consistant with a gummed up TB. The gum, or sludge, oil or what ever you want to call it, when cold is very sticky. As it heats up it gets worse

Not arguing that throttle bodies do get gummed up but I still can't see how this can be the source of my problem as:

1) I already had the TB cleaned by the agents when I got the t-belt done and it made no difference at all
2) how could a gummed up TB explain the fact that merely cutting the engine for one second and restarting it make the stickiness in the accelerator pedal go away instantly? Its not like I'm stopping the engine and letting it cool down. (If you read my original post again you'll see the problem shows itself anytime I floor the pedal and either goes away on its own after 5-10mins of continued driving or if I quickly stop and restart the engine.)

Well if you dont want to listen to advice then dont bother asking. Simple really

Your isc has no relation to your throttle plate for starters and when engine is off the vac is not there holding plate shut

Thanks but yeah like I said I did have the TB cleaned previously and it did nothing to improve this. I guess I'll have to give it a go myself, maybe the guys at the service dept didn't do a thorough job cleaning it even though I told them in detail what my problem was.

Appreciate your pointing out that when the engine is off there is no vacuum in the TB that could potentially be holding something shut (I have never had a look at the TB butterfly on the Magna myself yet). I'm convinced now that my problem is somehow related to this. See, with the engine off (hot or cold makes no difference) the pedal/cable movement is smooth as silk right down to the floor. Start the engine and suddenly the pedal becomes sticky on the down stroke if you pass the 1/3 mark (approx).

Thanks again for all the helpful pointers, much appreciated. Will post an update if/when I finally get it fixed.

Thanks but yeah like I said I did have the TB cleaned previously and it did nothing to improve this. I guess I'll have to give it a go myself, maybe the guys at the service dept didn't do a thorough job cleaning it even though I told them in detail what my problem was.


Can't help with the actual problem, but this is a definite possibility, a lot of workshops 'clean' the throttle body by giving it a quick blast with TB cleanser, don't bother to wipe it down or anything, let alone give it a good clean. Can't hurt to spend $5 on a can of TB cleanser and give it a good clean out yourself.

Cheers. Any particular brand you use/recommend? I've heard that carby cleaner might be too strong to clean the TB bore on some cars (apparently there's a special coating), not sure if that's the case on ours.

Also, are there any sensors in there that I need to give a wide berth when cleaning the TB? I intend using TB cleaner and a toothbrush.

DO NOT take it to Mitsubishi!

They stung my old man $2200 while I was overseas for a replacement TB..

It's a sticky TB.. Give it a clean.. You could also clean the Plenum while you're at it!

SuFz

This problem i have had for a while as well.... It is very annoying as when i am trying to accelerate gently off from standstill, it jolts forward pass the accelerator pedals's sticky point. kinda feels like dunking the clutch on first, accept mine's auto.

Good thread... I know now how to fix the problem.

So that makes at least five of us who have experienced this exact problem on their 3rd gen: Me, Gas_Hed, VRX257, VR-S3X and assailantsky (see his thread here: http://www.aussiemagna.com/forums/showthread.php?t=75132&p=1182113).

Didn't get a chance to clean the TB yet but will certainly post an update with results when I get round to it.

VRX257, just out of curiosity, does your car have TCL?

VRX257, just out of curiosity, does your car have TCL?

Yup, Mine does have the TCL. I will open it on the weekend to see what i find.. I am pretty sure sticky throttle body.. .at 100k km, it has never been cleaned. I am expecting some gunk.

I cleaned the TB yesterday.... It did not take much effort at all.. Just squirt a little bit here and there in the butterfly flap area and wiped clean with a paper towel (especially the area of contact where the throttle plate snaps shut to the TB).

I could see how sticky it was before cleaning and how free it became after cleaning.

The resistance on the pedal is now gone.

I cleaned the TB yesterday.... It did not take much effort at all.. Just squirt a little bit here and there in the butterfly flap area and wiped clean with a paper towel (especially the area of contact where the throttle plate snaps shut to the TB).

I could see how sticky it was before cleaning and how free it became after cleaning.

The resistance on the pedal is now gone.

Cheers, good to know that fixed it for you. I was going to have a crack at mine too over the long weekend but couldn't get motivated with the wet weather we've been having in NSW :cry:

What cleaner product did you use? I asked at a couple of places if they had throttle body cleaner and they said they have the stuff from CRC and Nulon. Haven't had a chance to look closer at them.

Cheers, good to know that fixed it for you. I was going to have a crack at mine too over the long weekend but couldn't get motivated with the wet weather we've been having in NSW :cry:

What cleaner product did you use? I asked at a couple of places if they had throttle body cleaner and they said they have the stuff from CRC and Nulon. Haven't had a chance to look closer at them.

I used Nulon TB and Carburetor Cleaner.. It was $13 but well worth it. I did all my other cars as they were also sticky in the TB too.

HI have had same prob with 2004 magna. Just a little click when depressing pedal like it was caught on something. Then ok. Just away for 3 months came back and after recharging battery car would start fine but nothing happened when pedal pushed or manually openened. No tick on pedal either. have played with it for few days then it suddenly stuck/clicked and engine revs fired normally. No idea what the resistance is or why it cleared

had same prob ie sticky throttle cable. then cable was not sticking but car would not raise revs at all above idle. Fiddled for 3 days and suddenly it stuck/snagged then cleared and engine revved normal.
Definitely catching something but what ? as it seems that when it catches it works. Bit irish I know