Spongy Throttle

[nlau1 0]

Hi guys,

 

I've got a spongy feel to my throttle in the VR6. It also feels a bit vague and the pedal feel is not as "springy" as other cars I've driven.

 

Is this normal or is there a deeper underlying problem?

 

Thanks in Advance

[Kevin Bacon 5]

Seizing throttle cable? Or the soles of your platform shoes are very soft :D

[nlau1 0]

Haha, damn it Kev, I thought you weren't going to tell anyone about those shoes! :camp:

[nlau1 0]

Ok, on a more serious note... I've just been outside, started the car up and blipped the throttle a couple of times. Basically, when I come off the throttle pedal, it takes the engine about a second before it reacts and drops the revs. Anybody have or had this before? Or is that how its supposed to be?

[dannyboy 0]

get a buddy in the drivers seat to push the throttle and you have a look at the throttle cable+ body to see if its the cable or throttle mechanism thats sticky.also try it by hand ,you might see a difference between using cable and your hand. if it appears to be good then suspect a sensor failure

 

I know its general fault finding but it might help

[nlau1 0]

Thanks offhisrocker.

 

Its very good advice and any help is welcome! I'll have a look this weekend and keep you guys posted on this. I have a sneaking suspicion it might be carbon build up in the throttle body.

[Roan 0]

I'm intending to replace my throttle cable soon as I have the same feeling even though the throttle body has been cleaned out. It looks like there's some slack in the cable, even after adjustment so after 15 years I think it's stretched. Anyone know how much they are/should be before I phone the dealers?

[Supercharged 2]

They are about £20, new cable should sort it but also check the sleeve and the angle it goes thru the bulk head.

[Kevin Bacon 5]

I thought throttle cables were obsolete?

 

if the revs are staying high when coming off the throttle, it could be an Idle valve fault. I've never seen a Corrado throttle cable so bad that it holds the throttle open when off the pedal, not on the 2.9 at least as it has mega strong springs in it!

[nlau1 0]

Ok, bit of a thread revival, but I think its definitely throttle cable.

 

How do I know this? Well if i stick my foot under the throttle pedal, I can actually lift the pedal towards me about 3-4 inches!!

 

Anybody know if VR throttle cables are obsolete?

[nlau1 0]

OK guys, just been out and had a look at the throttle cable/mechanism whilst pumping the pedal.

 

Basically, when the pedal is left alone, the throttle mechanism sits as it should.

 

When I press the throttle, the mechanism is pulled forwards by the cable to about 90 degrees.

 

However, when I release the pedal, the mechanism swings back down and the moment is makes contact with the damper (red sprung boot, don't know the technical term for it!) it slows right down and then rests in its orginal state. (is this causing the slight delay I'm feeling between release of pedal and drop in revs?)

 

Is a slack cable causing this or is it something more complicated? I'm just sick of the soft spongy throttle, and I read on here a while back that someone adjusted their throttle cable and the end result was a pedal feel that was similar in resistance to the brake pedal. Right now, mine has nowherere near the resistance of the brake pedal!

 

Please help!

Edited April 13, 2011 by nlau1

[Roan 0]

I previously contributed to this thread as I have the same issue. I don't know if I'm being anal, but the spongy feel really annoys me. The fact that you (and I) can pull the throttle pedal up by a few inches would make me think the cable has stretched as the degree of movement can't just be down to poor adjustment as you can't adjust the mechanism that much! I'd love to try a new cable but I believe they're obsolete. I was wondering if it's a plastic washer or bushing in the pedal box itself that's the problem also...

[nlau1 0]

I previously contributed to this thread as I have the same issue. I don't know if I'm being anal, but the spongy feel really annoys me. The fact that you (and I) can pull the throttle pedal up by a few inches would make me think the cable has stretched as the degree of movement can't just be down to poor adjustment as you can't adjust the mechanism that much! I'd love to try a new cable but I believe they're obsolete. I was wondering if it's a plastic washer or bushing in the pedal box itself that's the problem also...

 

Do you have any more info on the pedal box issue you're suspecting? I've just adjusted the throttle cable but it doesn't seem to have made any difference, still getting a slight delay from pressing the pedal to the throttle body opening/closing. I've taken it to a VW specialist and they reckon theres nothing wrong and thats the way its supposed to be but I'm not convinced.

[Roan 0]

Not really any more info. As the car's a daily driver I can't take bits apart too much to investigate but I looked on Vagcat and there's a few nylon washers at each end of the pedal box axle that could be worn. I'm not convinced they're the main culprits though - I reckon it's still the throttle cable itself. I'm going to check where it passes through the bulkhead more thoroughly and also see if I can lubricate inside the sleeve in the engine bay to see if that helps. I may be being a bit OCD-ish too, but coming from an Alpha-N modified E39 M5 the throttle response is on another planet...

[nlau1 0]

Haha, I know what you mean mate, although not on the same level as your M5 I came from an EP3 Civic Type-R so its a bit strange in the VR now!

[Wild-Animal 0]

Hey, it could be the same issue I had, there was a delay in the throttle response. I put it down to the throttle cable.

 

I removed my throttle cable to see if I could put a bit of grease down it, but on closer inspection the cable had started to fray just ever so slightly and it was causing the cable to stick. Mine is a 16v but there is a sharp 90 degree bend just inside the cabin and that was the point were the cable has started to fray.

 

What a differnce once I replaced it !

 

So if your unsure about ordering a new throttle cable , whip it out first and have a look at the end with the 90 degree bend is where you should find the fraying.

 

The symptoms sound exactly like mine

 

Hope this helps

[nlau1 0]

Hey, it could be the same issue I had, there was a delay in the throttle response. I put it down to the throttle cable.

 

I removed my throttle cable to see if I could put a bit of grease down it, but on closer inspection the cable had started to fray just ever so slightly and it was causing the cable to stick. Mine is a 16v but there is a sharp 90 degree bend just inside the cabin and that was the point were the cable has started to fray.

 

What a differnce once I replaced it !

 

So if your unsure about ordering a new throttle cable , whip it out first and have a look at the end with the 90 degree bend is where you should find the fraying.

 

The symptoms sound exactly like mine

 

Hope this helps

 

Thanks mate, I think I'll go ahead and replace the cable anyway as its not an expensive thing to replace.

 

Where abouts is the pedal end of the cable? Is it on the inside or outside of the firewall? And how is it routed around the engine?

[boost monkey 0]

Yes everyone, the cable will stretch. At least two of you seem to be scratching your head over whether a few strands of steel wire will fatigue over time.

 

Ummm........

[Wild-Animal 0]

The cable is connected to the end of the throttle pedal by a small hook onto a rubber bushing, what to do is disconnect the cable in the engine bay so you have plenty slack. remove the interior trim right next to throttle pedal, this will allow you to remove the lower dash, once the lower dash is removed you will be able to squeeze underneith and see the throttle cable and a bit of wiggling the cable should be able to unhook. from there you work remove the cable. Work it free from where it enters the scuttle area , not sure about the rest as you VR6 will be different after that !

 

 

"Yes everyone, the cable will stretch. At least two of you seem to be scratching your head over whether a few strands of steel wire will fatigue over time.

 

Ummm........"

 

I think its more to do with the cable chaffing rather than stretching, like I said there is a sharp 90 degree bend and the cable is pulled through the corner and it rubs onto the cable causing the cable to adventurely fray

Edited April 25, 2011 by Wild-Animal