throttle stiffness

[tomsky]

Just wondering how stiff should the throttle pedal should feel. Mine now seems hard to apply and inital amount of pressure when idling ans is quite difficult to feel whats its doing or apply a small amount without over doing it when taking off. Compared to my celica which feels a lot lighter and progressive im wondering if it needs some work or a new cable

[elbon50]

Just wondering how stiff should the throttle pedal should feel. Mine now seems hard to apply and inital amount of pressure when idling ans is quite difficult to feel whats its doing or apply a small amount without over doing it when taking off. Compared to my celica which feels a lot lighter and progressive im wondering if it needs some work or a new cable

Definately needs investigating Tomsky

Mine is very smooth & light

never had a problem with that in nearly 15 years of owning the car

Try lubricating the pedal hinge perhaps ?

Peter

[HT]

Maybe try a Jimi bracket - a much better set up than the standard tripod thingey!

[LimeyMk1]

Whip off the air inlet pipe that attaches to the throttle body and clean all the gunk off the throttle butterfly, that's what usually causes sticky throttles.

Other than that check all the pulleys on the engine end of the throttle cable and the cable itself for fraying.

[Tiger Tim]

There's a little screw where the throttle cable attaches to the Throttle body in the engine bay to stop the quadrant (someone else will explain this more technically) going back too far. At one stage when I was trying to bring the revs down, I loosened this too much & the quadrant (circular thingy with accelerator cable attached) was going over centre & back too far. This would cause stiffness in the pedal on initial application, OK when up & running, but a PITA in traffic. By adjusting this stop out a bit, it resolved my problem.

Tim

[un1eash]

Is the throttle easy to move by hand? It could be the cable is starting to stick and if it is the cable then thats a cheap and easy fix.

[FossMan]

Yeah I was going to say the cable. Mine started to get heavy/sticky when it was frayed on the inside... then it snapped on a dual carriageway when I planted it

[greglebon]

If not a damaged cable, check the butterfly valve itself is not sticking to the housing.
This is usually caused by the fitment of most cheap oil-coated filters, ESPECIALLY if it is too small for the job.....Proper K+N, Pipercross filters made for the application are usually ok....

The flow of air pulls the oil off the filter and it gradually coats the valve (and can block the idle valve holes, etc...) and the throttle housing.

The effect of this is that over time the valve sticks closed when at idle (traffic lights, etc), requiring more pedal pressure to release it...when it suddenly frees up, your foot goes down...boy racer syndrome..!

Happened on my V6 Mk3 recently: now running an AEM dryflow filter to prevent a repeat......

Clean it all with Wynns Carb + Injection System cleaner...job done...

[LimeyMk1]

Greg the oil on the throttle butterfly is more likely from the cam cover vent, the hose may look like it vents straight into the inlet manifold but it actually exits just before the throttle butterfly.

I imagine a filter that's too small won't help due to an increase in vacuum in the manifold.

[greglebon]

This wasn't oil......It was sticky: tacky to the touch....

Oil, you can wipe with your finger, and it comes off, leaving the metal underneath...this was actually a sticky goo!

Only thing upstream that would cause this was the filter.....and it hasn't re-occurred, either....