172 Ph1 Tbody help

[ed1801]

Hi there,

I find the throttle control on my 172 Ph1 absolutely rubbish compared to my MX5 and i was wondering why!

The problem is that the accelerator is so hard to push that it is (nearly) impossible to use small throttle openings correctly. If you want to open the throttle a little bit, you push and push then suddenly the pedal jerks down and you have way to much power on. It's the same the other way - you want a little bit less power to tighten the nose on a corner so release pressure on the accelerator, then suddenly it moves a long way under your foot causing you to tighten a lot more than you intended

On the mx5 it is a cable throttle, but it was really really light and did exactly what my foot was telling it. On the 172 it is heavy and sticky.

I changed the cable, which helped a little bit, but tbh the cable i took out had bu**er all resistance in it anyway. What else could be wrong? Is it a characteristic of this car not to be able to control it???

Another thing I thought of is that the accelerator cable routing is weird as. I was thinking that I might get a shorter cable and have it pulling from the bottom of the tbody so that i eliminate the 180° bend by the pas reservoir, and also eliminate half a meter of cable.

It could also be that my tbody is a bit sticky (it has been cleaned), but when you take it off, the spring is strong and it shuts correctly. When it is on the car it feels a little bit sticky at the almost shut position.

What do you guys reckon?

Thanks

 

[ianeire]

Similar symptons here, hopefully some enlightening answers . . .

 

[ed1801]

Similar symptons here, hopefully some enlightening answers . . .

Hopefully

 

[Rob669]

See the guides section. I wrote a note about this problem. It helps if you try routing it differently.

 

[Andyman]

Reason why the cable takes a strange route is due to the fact its in effect a left hand drive car converted to a right hand drive market.

TB shouldnt be a problem unless you notice it reving up or the revs staying high. Would need to be very gunked up to hold up the revs and r****d the spring back

Try adjusting the route the cable takes. Could maybe oil moving parts in the throttle chain like where the cable goes through its outer cable etc

 

[ed1801]

I followed your guide when i replaced the cable first time round - it was really helpful thanks.

I will make sure that the routing is exactly the same as in the pics again. I remember it clipped into all the existing clips fine and looked similar at the time.

Yes, the revs frequently stick high. The throttle isn't closing properly. But it is also really stiff to open and hesitant to shut via the pedal. The cable is new (and I put loads of oil in it when i got it), and when you turn the tbody by hand it is smooth and doesn't stick, so i guess that only leaves the cable routing?

Thanks for the replies.

 

[ed1801]

See the guides section. I wrote a note about this problem. It helps if you try routing it differently.

Doh! Just rechecked the routing. There are 3 or 4 clips the accel cable goes through - the first from the accelerator cable causes a really sharp down and then left bend in the cable (from drivers seat). Furthermore, I found that just beyond this clip there was a fairly tight down and up bend. I unclipped it from this and routed it more like in your guide. The accelerator cable is now light as a feather!

Thanks for your help - and to anyone else with a sticky throttle, get a new cable and install it like shown in the guide - ignore the first clip at least!

Thanks again

Ed