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Throttle stuck open

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A.Wang

New member
After driving my S2...ahem spiritedly...today, the car refused to idle at the normal 800-odd rpm, instead it was stuck at 2000 rpm with the clutch fully down or in neutral. I took the car home pretty promptly when I noticed this, but after switching the engine off and back on again, the problem went away (you can probably tell I work with computers for a day job), and the car was happily idling steadily at the normal sub-1000 rpm range.

Has anyone experienced this before? I looked at the throttle cable, and it looks fairly new - definitely not stretched. The accelerator pedal seemed OK too - it's not sticking down as far as I can tell.
 
Check your TPS- may need a little nudge. You might find the adjustment is a little out when the car is hot, but clicks off OK when cold.

Clarks Garage has the procedure if you need it.

Might also be worth cleaning up the throttle body to make sure the flap can close fully without any obstruction.
 
Thanks for that mate - I found the relevant page on Clark's, so will give that a go when I'm next in the garage.

Could this be caused the infamous DME switch problem, which can be fixed with a 17 quid bit of new plastic and metal?
 
Or you can try the subtle route. Get a lump hammer and use it on the floor pan right in the corner of the drivers side floor. This is typical symptoms of someone in the past mistaking the nipple shaped thing under the car in that location. It deforms the floor pan which is where the throttle cable runs, and can cause the throttle to jam open.
 
Mistaking it as a jacking point, just to clarify Scott's post. I agree with him by the way.
 
This is typical symptoms of someone in the past mistaking the nipple shaped thing under the car in that location. It deforms the floor pan which is where the throttle cable runs, and can cause the throttle to jam open.
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Wot he said. [&:] That jacking point is for a 4-post lift, and only designed to take 1/4 of the car's weight.

If you've had the car jacked up by someone like quickfit or the AA, it's a distinct possibility.
 
Hmmm ... my experience of bending the drivers' side floor is that the throttle jams wide open, not a little bit open. Idle would be on the red line, not 2000 rpm. And it would be practically undrivable.

I'm with Ed in suspecting the TPS.


Oli.
 
In my experience when the floor has been bent the pedal feels heavier and sticky throughout its travel, so I suspect you'd notice it if that was the cause.
 
Mine stuck wide open the one time it happened to me, but I can't say I felt it through the pedal, and it didn't stick every time it was opened wide either. Logically if it was bent less severely then the effect would be less severe and here it could be the spring can force the pedal most of the way back; that was my thinking anyway. I had a TPS sticking, and it's a pretty weedy component to stick the throttle with the tiny leverage it has on the spindle.
 
Hi

I had exactly the same problem a while ago scared me half to death, was trying to catch the lights at around 4000rpm and couldn't stop, only by turning the engine off did I slow down. For me it was (i'll try and describe it as I'm not the most technical). Under the bonet where the cable comes out there is a spring loaded thing, this was sticking.

I found it out by pushing it down and noticing when it returned it was say 1400 rpm and i could pull it back a bit more bring it down to 900ish, so I WD40'd it and slapped some grease on.

It did it once more so i repeated the treatment and have never had it happen again. I think it was back in 2007, I got the same advise you did.

It's an easy test,
 
The symptoms are varied depending upon how the floor pan is deformed. With me the symptoms I got was that sometimes if I blipped the throttle whilst stationary the revs wouldn't return to normal idle RPM and would stick at say 2500rpm. I never had any occation where the throttle stuck at WOT or even partial throttle. Anyway a few 'taps' with a lump hammer cured it (if you're squeamish then you'd best turn away when the chappy does this).

I can guarantee that almost all 944's would have had this treatment at some stage through their live.

Just for the record I don't think those nipple featrues at the front are for jacking at all under any circumstances. I think they are locating features for the stand the shell was suspended in on the production line. The only jacking points are inboard of the nipples where the square section tube blends into the floorpan for the rubber covered domed dish shaped pads you get on garage jacks. Other than that is it the normal jacking point in the middle of the sill. I've got a good underside photo on my computer at work illustrating all the jacking points and it specifically says never to use the nipples for jacking!!
 
Found the underside photo highlighting jacking points and more importantly where not to jack.




E5DF02B46E9442278AF24FD14842A7C6.jpg
 
Could the problem be the "infamous" idle control valve ,,,sticking.?????
Or does that have "other" symptoms when failing.????
 
The root cause of this has been traced...it's down to someone jacking the car up on the floor and creating a weak point in the driver's footwell. Over time that has rusted through - there's actually a hole there! The boys at EMC only found out when they pulled the carpets out to weld the cage...looks like I'll need a new floor - and the fuel lines will have to come off for that too, so that could be quite pricy! [:eek:]
 
Sorry to hear that, what a nightmare [:(]. Thankfully the floor itself is quite cheap, I'd offer you what's left of mine for a good price but I suspect yours has gone in the same place mine did...
 
I haven't been up to EMC since the discovery, but I've been told the best way to repair it would be to cut away and weld in a new driver-side footwell.

I seem to remember reading somewhere on here that a new floor itself is less than 100 quid from an OPC, it's the labour that I'm more concerned about!
 
ORIGINAL: A.Wang

I haven't been up to EMC since the discovery, but I've been told the best way to repair it would be to cut away and weld in a new driver-side footwell.

I seem to remember reading somewhere on here that a new floor itself is less than 100 quid from an OPC, it's the labour that I'm more concerned about!
Click to expand...

I paid a bit more than that, it was £290 +vat last year but it's a very big piece of metal so I think that's pretty good value all things considered. I suppose you have to question whether to start again with a fresh shell at some point, but if the rest is sound I guess that wont be cheaper.
 
ORIGINAL: Peter Empson

ORIGINAL: A.Wang

I haven't been up to EMC since the discovery, but I've been told the best way to repair it would be to cut away and weld in a new driver-side footwell.

I seem to remember reading somewhere on here that a new floor itself is less than 100 quid from an OPC, it's the labour that I'm more concerned about!
Click to expand...

I paid a bit more than that, it was £290 +vat last year but it's a very big piece of metal so I think that's pretty good value all things considered. I suppose you have to question whether to start again with a fresh shell at some point, but if the rest is sound I guess that wont be cheaper.
Click to expand...

The rest of the car is very solid - the car didn't have the infamous rusty cills or wheel arches, so I thought I got lucky...the EMC boys must've thought the rest of the car's really tidy too, otherwise they wouldn't have started welding in the cage.

Apparently it's not something I could've picked up when I looked at the car, so I don't feel too guilty about not spotting the problem before buying...it's just annoying that I'm adding a few hundred quid on top of the build costs! [:(]
 
Well at least you can be safe in the knowledge that EMC wont attempt to rip you off with their labour costs...

I'm off there in a minute to pick up a battery... so I can have a gawp at your car while I'm there.
 
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