KTec ITB throttle linkage sticky? Better spring?

[KitsonRis]

Now I can use the car as it has been mapped I am just going through a snag list before I can use it.
It was noticed when mapping that the throttle sticks ever so slightly. Does this if gently opening the throttle and then gently lifting off. Does this with the throttle pedal or manually moving the linkage which leads me to beleive it is the linkage and not cable routing. Suggested that I put a stiffer spring on the linkage to help it.
Spoke with KTec and they said there was another spring to fit on the other end to the TPS....so there is!! Got it out and went to fit but from what I can see it is all wrong and the way this spring coils is backwards - so when the throttle opens the spring un-coils.

<-- this doesn't even work!

Looking at the linkage between the banks of the bodies there are two springs, it looks like I have been given the oposite (blue) one to what I need (green)

From what I understand they are now using a new TPS in their kits which is now cambelt end. It looks like the spring I have been given would work on the cambelt end - I have email KTec again to ask if this is the case and they need to supply the opposite spring (I didn't get a reply today as I must have missed them being a bank holiday, they have been very helpful during this work).

I have managed to find what looks to be the right spring online which I have bought, for the sake of a few quid it was worth the punt.

Any other suggestions to try? It is as if there is a small flat spot in the mechanism too - but I can't tell if this is becuase the two body banks and not quite suare, the springs in the middle are just coiling/catching or the throttle cable. Will remove it tomorrow and see if that resolves it.
I am going to loosen the bolts that holt the bodies to the head to try and re-align them as a starter. I also have a new throttle cable on the way as I know I need to re-route it (third time lucky!!)

 

[barnesautos]

I’ve seen the butterfly start to catch the runner which in turn with give a similar fault .

 

[kurai]

Now I can use the car as it has been mapped I am just going through a snag list before I can use it.
It was noticed when mapping that the throttle sticks ever so slightly. Does this if gently opening the throttle and then gently lifting off. Does this with the throttle pedal or manually moving the linkage which leads me to beleive it is the linkage and not cable routing. Suggested that I put a stiffer spring on the linkage to help it.
Spoke with KTec and they said there was another spring to fit on the other end to the TPS....so there is!! Got it out and went to fit but from what I can see it is all wrong and the way this spring coils is backwards - so when the throttle opens the spring un-coils.

View attachment 1638000 View attachment 1638001

View attachment 1638002 <-- this doesn't even work!

Looking at the linkage between the banks of the bodies there are two springs, it looks like I have been given the oposite (blue) one to what I need (green)

View attachment 1638004

From what I understand they are now using a new TPS in their kits which is now cambelt end. It looks like the spring I have been given would work on the cambelt end - I have email KTec again to ask if this is the case and they need to supply the opposite spring (I didn't get a reply today as I must have missed them being a bank holiday, they have been very helpful during this work).

I have managed to find what looks to be the right spring online which I have bought, for the sake of a few quid it was worth the punt.

Any other suggestions to try? It is as if there is a small flat spot in the mechanism too - but I can't tell if this is becuase the two body banks and not quite suare, the springs in the middle are just coiling/catching or the throttle cable. Will remove it tomorrow and see if that resolves it.
I am going to loosen the bolts that holt the bodies to the head to try and re-align them as a starter. I also have a new throttle cable on the way as I know I need to re-route it (third time lucky!!)

I had same issue (kit bought on 2020). Not so much noticeable when cold but slitghtly noticeable when hot.
I checked everything and even if the cable was running smoothly it seemed to be lile the pedal not properly seating in lifted position.
I simply attached a spring to make pedal return in place.
This not only sorted the problem but also gave better feel (felt too light before)

 

[KitsonRis]

I had same issue (kit bought on 2020). Not so much noticeable when cold but slitghtly noticeable when hot.
I checked everything and even if the cable was running smoothly it seemed to be lile the pedal not properly seating in lifted position.
I simply attached a spring to make pedal return in place.
This not only sorted the problem but also gave better feel (felt too light before)

Attached a spring where? On the back of the throttle pedal? Got any more details and info on this?

 

[kurai]

Sure, I attach a picture of it.
Gas pedal is from non sport because I have non sport pedalbox, but the idea can work also on std 1*2 pedal.

The L shaped thing is an adjustable travel limiter I made, it has a rubber stop.
Anyway drilled a little hole just above throttle cable and then fabricated a little L with a hole to attach the spring.
i fitted that L under one of those oem nuts (replaced the bulky oem with a nyloc to compensate L thickness).
Works as a charm for me.

 

[kurai]

 

[markmcgivern]

Glad someone created this topic! I've been running ktec bodies for 5 plus years and had the same issues. I fitted spring to top of the pedal which gives a much nicer pedal feel and cured the same issue

 

[VenomUK]

You’ve beaten me to it. After reading this the first thing popped to mind was to add a return spring to the accelerator peddle in the peddle box to aid in pulling the peddle back to its home/closed position. What @kurai has posted is exactly what I would have done

 

[KitsonRis]

Going to take a look at the pedal spring return as well. The spring for my throttle body should arrive this week so that will be something to also try.

 

[kurai]

Going to take a look at the pedal spring return as well. The spring for my throttle body should arrive this week so that will be something to also try.

I honestly opted for that because I thought the itb spring was doing its job shutting them down correctly. It seemed to me more of a problem not of cable drag (its super smooth and I have very linear layout) but pedal movement. To me the problem is pedal shape. Is a bent round bar and I noticed it can move on its plastic bushing from side to side a lot, doing so if it goes too much on the side when on slow release the bend make pedal not to move smoothly on the bushing because near the edge its not a perfect square bend.. putting the spring there it just help it set correctly and go to home position without pulling it with cable from the bodies.

 

[VenomUK]

I think in this instant you can't have enough springs to get that position to close quickly enough, beefing up the springs on the ITB and a good one on the pedal is only going to improve things and snap that throttle closed. As it has been touched on, I also think it will give a greater feel to the pedal when feeding in and out of the throttle.

 

[KitsonRis]

I have just heard back from KTec and they agree I have the wrong spring and should have been given two. I’ve asked if they will send out another as I was only given one. But will put this on (should be better than the one I sourced) and then look at a throttle pedal return spring.