Smoothing the throttle

[Scougar]

Hi guys :)

My valver throttle is very on/off (very sensitive when first pressing). Is there a way I can get it more like a more modern car, and have the 1st inch(or whatever) a gentle build up rather than gently touching it and the car lurches? (throttle dampner?)

It is currently making traffic jam driving a pain in the butt, and uncomfortable unnecessary small lurches for me and passenger.

Matthew

[Rich]

oil the moving parts. should free up the response more. also check the throttle cable isnt worn.

[Scougar]

Will try it. Not sure it will do much though, was same on my metro gti, although not quite as bad at the initial press.

Matthew

[Coops]

try adjusting the cable at engine end, theres a little ribbed sleeve and circlip you can use to lengthen the cable, mite still be jumpy bit more pedal travel to work with as a start

[cliolord]

I know that when I wound the idle screw adjustment out on the throttle body this had the same effect, very touchy on throttle for obviously reasons, the thorttle potentiometer was setup wrong (but dont touch this believe me!! :lol: ) and it maybe you dog bone mount thats making it jerky

[Scougar]

Thankyou guys. Those are all great suggestions :)

I tried taking a look at it this evening, but it starting chucking it down again :( It's been raining for the past week! (since I got the car lol). Wouldn't be suprised if it was the mounts.

I did manage to quickly soak it in wd40 (whilst raining and dark), but rain was so heavy whilst driving fiancee home, my focus was entirely on the road wasn't thinking of "this feels wierd". I will see what it's like tomorrow.

Matthew

[Purple]

Take out the air filter, and check that the 2 butterfly valves are not being activated together (sticking). A lub and clean will sort them out.

[Scougar]

Oh really, dual butterflies? Will take that out on Monday and have a look. I have carb cleaner/lube etc so no problem there.

Whilst I'm looking at the air filter, which is the MAF (Air sensor)? I would like to take that out and spray it off with carb cleaner as well in case it's coated in oil/dirt or something. Is it the red unit attached to the throttle section?

Matthew

[stan]

They dont have a MAF sensor. Red sensor is throttle pot. This may need adjusting.

[Scougar]

No air flow sensor on a multipoint injection :shock:

Will check out the butterflies, and read up on the throttle pot adjustment.

Hopefully doing all this will also sort out the effect of putting your foot down for a brief moment the exhaust/intake begin to sound great, then it dies of and the acceleration (for about 0.2 secs) stops, almost liked it's being stifled. Maybe just need to get a new air filter and give it a good service. Will report back on throttle/butterfly condition.

Matthew

[stan]

no, works off bith MAP and TPS for load

[Scougar]

Hmm.. wouldn't that mean that the ECU will have a hard time adapting to a different air filter and decat for example? (and will run more lean).

Matthew

[Scougar]

If it stays dry today, and if the new blower hasn't arrived to fit, I will be taking apart the throttle assembly and giving it a good little service tonight :)

Will also pay attention to the TPS as the car tries to die for 1st 30 secs of driving sometimes (or when idling for about a minute initially [revs drop then cars dies]).

I shall let you know the results :)

Matthew

[Scougar]

The top small butterfly opens before the larger bottom one, so all good there :)

Cleaned and refitted the TPS. Will just have to wait and see what happens with that over next few day.

I did however refit the throttle cable clip so there is hardly any slack in the cable before the throttle is moved. That seems to have helped with my judgement as well.

I Took a look at the dog bone, but will need an assistant to rev whilst I watch it to see if it's bad or not. The engine does seem to move quite a bit on revving however.

Matthew

[stan]

Have you reset the TPS?

And no, a filter wont change fuelling...the MAP sensor will pick it up as an altered internal pressure change.

[Chris H]

most of the time the cars I get in the throttles terrible due to people clipping the cable 'out of the way'

make sure its routed correctly and that its clippe dinto the bulkhead at the pedal end properly AND that the cable where is joins the pedal is in the right white plastic clip and a not a solderless nipple

[Scougar]

Throttle feels quite nice now really.

How do I "Reset" the TPS? I was messing with it and getting it in a position that gave around 1000rpm or just under.

Matthew

[stan]

reset to factory values. If uve got it sweet as it is, then it sounds about right.

[Scougar]

I think I may need to 'tweak' it very slightly, but seems better since I fiddled with it. I may need to take it off again and gently sand the face of the it smooth, as it seems to be difficult to position without it wanting to go back into the original groove/indent.

Car still feels like it's holding back though, so more work to do.

Matthew