throttle stuck

[Robbiet9999]

Help.

after doing some work on my morris and not starting her for a few months i decided today as its nice and warm lol to go outside and allow her to run for a while. i put fresh fuel in the tank checked the oil and water tried to start her battery was flat so out come the leads and a jump start from the wifes ka. she started and immediately the revs went up to 5000 and stayed there with blck smoke coming out the exhaust so i turned her off to prevent any damage. what would cause the throttle to stick. the cables are fine and in their usual places both throttle and choke. could there be something inside the carb that has got stuck.

any advice is welcome.

[bmcecosse]

Throttle must be held open somehow! So check the cables etc. Possible also if the earth lead from the gearbox is not good - for starter current to find it's way to earth through the choke and acc cables - and in so doing to weld them to the outer sleeves.... So check if they are free!

[Robbiet9999]

hi bmc

have checked the throttle cable and choke cable both are free. will get picture of carb to see if any light is spread. throttle moves freely and sits on its rest. not sure on choke could the choke get stuck inside the carb

[chesney]

Take the air filter off and (not running) see what the spindle is doing ie is it fully open (which it should be a 5000 revs!). If not, the only thing I can think of is an air leak from a gasket or something.
Assuming the carb is a standard HS2 (?) check the choke can move freely ie the jet is able to move up and down freely.

[Robbiet9999]

i have takien some pics of the linkages does anything look odd.[frame][/frame][frame][/frame][frame][/frame]

[chesney]

It looks as though the throttle is being held off it's rest position. Don't try and force it, maybe give the throttle pedal a couple of gentle presses to see if that frees it off. If not, disconnect the cable and see if the throttle drops.

[Robbiet9999]

the throttl is at rest as the lower of the screws is sitting on the rest it sits on so could it be the thing the upper screw sits on is stuck

[chesney]

Ah I see, it's a H2 carb, I was assuming it was an HS2!
Perhaps someone more familiar will be able to help..

[bmcecosse]

Throttle does look to be held open there..... but not by the choke ! Check the pedal inside the car isn't stuck on mats etc. Also check under the bonnet - where the cable comes through to see if the nipple has come out of the seating and is sitting on top of the seating thus holding the cable taught....

[les]

What about checking the return spring

[bmcecosse]

Good point les - is that the return spring we see in the foreground of the 3rd picture??? If so -surely in the wrong place?

[mike.perry]

The accelerator spring should attach to the throttle lever at one end and normally a bracket on the manifold/exhaust clamp at the other so that it holds the throttle closed.
Next slacken the accelerator cable clamp then wind the fast idle screw up until the tickover screw rests on the stop. Tighten the accelerator clamp screw leaving a little slack in the cable, checking that the outer cable is properly located at both ends.
Start the engine and adjust the tickover screw to get the correct engine speed and when the engine is hot slight re adjustment may be necessary.
Finally adjust the fast idle screw so that it just touches the cam

[Robbiet9999]

The throttle spring is in the position it has always been in. The cam however looks to be out of its normal place as the tick over screw is in its resting place and the fast idle screw is nowhere near the cam. What does the cam control internaly .

[bmcecosse]

That's not right for the throttle spring!! If it's operating on the opposite side of the throttle spindle to the cable (as it seems to be) then it is putting tremendous wear on the spindle and bushes. Obviously something has slipped - what were you doing to the car? Take the spring off and move it so it acts directly opposite the throttle cable - it should hook on there and then connect to a bracket low down on the exhaust clamp.

[kennatt]

the spring cann't work where it is ,whats it fixed to. There is no sign of a return spring fixed to the lever where the throttle cable fixes to the carb, Show us a photo of the spring attachment points. Just beat me to it BM

[Robbiet9999]

here are pics of return spring. was originaly clipped into air in take on original air filter.[frame][/frame]

[moggiethouable]

That cable looks awfully tight?

[bmcecosse]

That's not a good way to run the cable - as explained - it wears the spindle badly. I agree - the cable is taught - something is pulling the throttle open via the cable.

[Robbiet9999]

Have checked the pedal it is resting against the bulkhead where the cable comes though. Will remove the cable completely once it stops snowing. It was a new cable in the summer time.

[Robbiet9999]

I decided the snow can go somewhere else. So i went out and removed the throttle cable. Jump started her as battery had gone flat again. She ran fine no racing all the way up t 5000 revs instead she ticks over at just around 600-800 rpm. So is it common for throttle cables to shrink in cold weather.