Sticky throttle - XF ute, 250 xflow, 34Weber

[Mr Polson 10,214]

Okay guys as title suggests I'm having issues with a sticking throttle on my ute.

At first it only done it at WOT but now it's doing it almost across the pedal range.

 

Sprayed the heck out of the carby (outside and down the throats) with carby cleaner, that fixed it up for a day or two but now it's back.

 

I plan to pull the carby off and examine the base see if I can spot the issue, but was wondering if anyone else has had similar issues before?

[unfamilia 1,938]

Is it the cable sticking in the sleave. Happens on other cars why not a ford.

[Ando81 2,949]

I have heard that the butterfly shafts can wear the aluminium housing of the carby and jam up now and again. All I did was put a stronger return spring on my carb and have it pull down to the inlet manifold to eliminate a possible over-rev between gear changes. It works well but throttle is a bit stiffer because of it.

[adrianphu123 73]

disconnect the cable from the carby, then you can isolate the problem to either the carby linkage/shaft or the cable itself.

[ando76 4,354]

Have a look for binding in the cable above the exhaust manifold/extractors.  As said above, disconnect the cable and isolate the issue.  I would suggest it might be carby based given that a spray improved it and then it came back.

 

Be careful putting on to stiff of a return spring - especially on a holley. Doing so can wear the hell out of the throttle shaft bush in no time and can lead to a lean condition as air (and dirt) gets sucked into the carb through the worn bush. 

[gerg 10,871]

When I pulled the 4.1 out of mine, it sat in the weather a little and both throttle shafts seized solid. I think Webers might be a little tighter in clearance than a Holley or something. Maybe corrosion is causing the two metals to gall up and bind, or maybe as Ando said, there is so much wear that the butterfly is binding on the carby throat. Do as Adrian suggested and pop the ball linkage off to see if the carby still sticks without the cable attached.

[Mr Polson 10,214]

Cheers guys, I'll do that tonight after work - weather permitting.

 

I'm 95% certain its carby based, because when I open the throttle manually at the carb, I can feel a stiff/stuck part.

 

The cable itself physically looks good above the exhaust too, no binding/kinks/cracking like most have.

[unfamilia 1,938]

Cheers guys, I'll do that tonight after work - weather permitting.

 

I'm 95% certain its carby based, because when I open my pants manually at the zip, I can feel a stiff/stuck part.

 

The shaft itself physically looks good too, no binding/kinks/cracking like most have.

fixed for tasmainia

[Mr Polson 10,214]

 

fixed for tasmainia

 

Tasmania.

 

Jealous mainlanders who can't spell properly.

[unfamilia 1,938]

Yep. Its not that your part of australia or anything..... that would be new Zealand

[Mr Polson 10,214]

So had a look tonight, disconnected the throttle and cruise cables, still feels like it has a stiff bit, but it didn't actually get physically stuck.

 

Started the motor got it to OT and tried (still with cables disconnected), and had the same result, stiff (after about 3/4) but not actually sticking.

 

Will go for a short drive later in the week to try and eliminate if its the cruise cable doing it.

 

Did notice slight kink in throttle cable too, must be fairly new, don't remember it being there before.

 

[ando76 4,354]

There is your problem my friend - that is a pretty major kink there - caused by heat transfer from the extractors - very common.  I have to shield my cables on the race and burnout cars for that very reason. 

 

I have seen a cable kink and bind like that on the race car while it was on the dyno.  We had the dyno fan off (because we were doing some EGT comparisons) and the heat rising from the extractors just destroyed the cable in seconds - not happy Jan as it was a brand new cable.  hence the reason why I now shield my cables. 

[Mr Polson 10,214]

How do you shield them mate?

Will have to look at doing it I reckon, this cable is only 6-12 months old, and I haven't been driving a lot during that time, can't afford to keep buying new cables.

[ando76 4,354]

I use DEI slip on heat shield on my cables and a summit starter blanket as well.  If you have a look at my burnout ute build thread you will see a big section cut of my my bonnet above the extractors - that is why it is there - hot air rises.  Not achievable in your application so,

 

If the budget is tight you may be able to cut the outer casing off that cable to free it up - then

 

get a piece of rubber hose of the appropriate inside diameter and slice it down the middle,

 

slip that over the cable from the master cylinder over to the rocker cover,

 

zip tie it in place over the cable (not to tight) and where you cut the damaged outer casing off add a bit of electrical tape.

 

and sit back and look at you creation with a beer. 

 

I have found that when you go to a holley and an XE V8 cable there is a bit more length and you can route the cable away from the rising heat of the extractors much better. 

 

Whatever you do - DO NOT wrap your headers in fabric wrap - UNLESS you want them to rust away....

[ando76 4,354]

Just in case your a visual learner here is a photo of the skid ute set up

 

[Mr Polson 10,214]

Yeah I'd rather not chop up my bonnet

 

Will try freeing up the cable and see how I go, can always get another cable if need be.

 

I noticed when looking at it yesterday it'd be much better if it was possible to re-route the throttle cable, don't think that would easily achieved with a weber though.

 

And yeah, heard bad stuff about header fabric/exhaust wrap, so I don't plan on ever using it.

[slydog 7,873]

All of what Ando said is on the money but the only thing I don't know from experience is the header wrap but Q had the same stories of woe so I'll back them in there.

 

I actually use a ED cable on holleys the same as above and with rubber and a alloy sleeve but for my DCO weber setup the cable this time is mounted very low like down at the starter thru a rubber mounted PK clamp and back behind the rocker cover around the front to the middle carb.I am going to cover it in cool wrap sleeving in time but for mine mounting the cable under the extractors near the starter removed them from the immediate heat source and seems to be working fine so far with zero shielding yet.I know it won't work for your weber ATM but for future reference if you change carbs keep the ED cable in mind as it's long enough and use's the same pedal as a XF and can be had for like $10 from the wreckers.  

[slydog 7,873]

One thing if ever making or changing how the cable pulls or is operated it has to engineered correctly or you will hate it forever.Needs to have as smooth arc's as possible and the straighter on the pull end the better.

 

 

 

 

This is not perfect but it works fine ATM.

[unfamilia 1,938]

I found that you can get 90deg metal bend sleaves from bike shops to get cables to go round bends properly

[Ando81 2,949]

One thing if ever making or changing how the cable pulls or is operated it has to engineered correctly or you will hate it forever.Needs to have as smooth arc's as possible and the straighter on the pull end the better.

 

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This is not perfect but it works fine ATM.

 

Great work there mate, looks a treat

[Mr Polson 10,214]

So i did end up taking it for a test drive yesterday, with the cruise cable disconnected - never got around to wiring the cruise in anyway - and didn't have a problem at all. Still not 100% certain (I'll wait until I do another 400km trip and don't have an issue.

 

Will look into fixing the kink and shielding it though, this actually has a crack in it, and the wagon has multiple cracks in it.

[gerg 10,871]

You have to be careful with the shielding. My old man's XF had a set of Genies that came very close to the clutch cable and cooked a couple of them,so he wrapped it in header tape. Turns out that stuff does as good a job of keeping the heat in as keeping it out, ended up cooking the cable the entire length that it was wrapped instead of just in one hot spot.