Throttle Body Carbon Build Up

[Big E]

Hi All, Another one for you...

My throttle body likes carbon...... Since Ive had the car (2 months) I have had to clean the bit by the butterfly. (once a month)

There must be a reason for the build up. Is this common.....Is there a cure...

I use Super unleaded and redex... The car had a full service 6 weeks ago...

Can be a bit scary when it sticks....You have to kick down on the pedal to release it..

Any comments will be appreciated... (as long as there about the car problem)!!!!!!!!!

Cheers

big E.

[GT4 BOOSTER]

does the throttle pedal feel like its jammed 1st thing in the morning??

[Big E]

does the throttle pedal feel like its jammed 1st thing in the morning??

Hi again, No it seems to stick when it gets hot or I have just put my foot down.

The butterfy seems to jam... and I have changed the butteryfly once....

I have to stamp on it for it to release....

Even when under the bonnet and reving it directly it can jam...

This morning I found out that you can get 3 vehicles around a 2 vehicle bend.... Bit scary... I had to breath in..

I take off the air intake so I can see the butterfy and clean the surrounds...

Its then ok for another 3 weeks... Very strange....

Cheers again

big E

[cfc1]

The causes can be varied, the two most common causes are..

1. Short trips... when the car is onlu used for short trips it might not be getting hot enough to burn the carbon deposits away.. a bit like a chimney if the fire isn't hot enough.

2. Running too rich.... fuel-based carbon build-up occurs when an engine burns an excessively rich air/fuel mixture. Too much fuel will tend to produce a relatively large amount of carbon waste that is not as thick as oil deposits but it is hard, dry and tougher to remove.

Info from.. here

[cfc1]

If this sounds familiar...

I have an auto 96 Subaru Legacy which has a problem. When the car is

hot, i.e. having been driven for 30min or more, when I pull up to a

stop the accelerator sticks and I can feel the car trying to pull away.

Whilst this is happening, if I put the car in neutral it is reving at

1800rpm. To fix this all I have to do is tap the accelerator pedal and

it returns to 800rpm. Now, I have sprayed the cable and springs on the

assembly for the efi with WD-40 but this didn't help. I have also

sprayed the origin of the cable near the pedal but this also hasn't

helped. Apart from replacement, is there a way I can stop this

happening. Thanks!

....try this..

Just a few generic suggestions: check the

linkage movement at the pedal and throttle body,

look for burrs, kinks or "anything else" that's

preventing

the return spring from doing it's thing.

If you have cruise control, check that cable too.

Make sure the cc cable is "slacker" than the

accelerator pedal cable, ie when throttle body is

closed, the cc cable should be looser than the

accelerator pedal cable.

A quick & dirty check for cc cable involvement

would be to disconnect it at the throttle body

end.

[Big E]

The causes can be varied, the two most common causes are..

1. Short trips... when the car is onlu used for short trips it might not be getting hot enough to burn the carbon deposits away.. a bit like a chimney if the fire isn't hot enough.

2. Running too rich.... fuel-based carbon build-up occurs when an engine burns an excessively rich air/fuel mixture. Too much fuel will tend to produce a relatively large amount of carbon waste that is not as thick as oil deposits but it is hard, dry and tougher to remove.

Info from.. here

Hi there,

Thanks for that. I travel 30miles ish each way to work so it cant be the short trips...

I am going to de cat it this weekend to see if getting the exhaust gases out quicker will help.

It done this when i bought it, hence the buttery change and I have recently put a K&N 57i induction on it.

Makes me wonder if that might not be helping matters,,, To much air...

The carbon is not black & sticky its more of a dry build up....

Maybe I should just clean it every other week and keep going....

If all else fails I will try a new cable......

I suppose its just a case of elimination... thanks for the imput...

Cheers

big E.

[cfc1]

If your running too lean then the car will be adding more fuel to the micture to rectify it (I guess) with that in mind my thoughts go to your induction kit, a few members on here have had problems with the K&N on the Corolla after fitting one... too lean.

Having looked at one the other week I'd hazard a guess there might possibly be a vacum leak where the MAF sensor goes due to a bad fit, this must be perfectly sealed.

Try removing the K&N and see if it stops the carbon building up as quick.

Are you getting any error codes?

[GT4 BOOSTER]

try turning the small screw on the bracket where the throttle cable goes . it has a nut on the underside 8mm i think . screw it down about 2 threads , best done with a hot engine so as not to alter tick over speeds.

[Big E]

try turning the small screw on the bracket where the throttle cable goes . it has a nut on the underside 8mm i think . screw it down about 2 threads , best done with a hot engine so as not to alter tick over speeds.

Cheers Guys....

I will keep you informed of how things go by using the process of ellimination....

big E.

[Big E]

Just thought I would finish the thread...

The decat has seemed to make the car behave...

I dont have the sticky throttle anymore..

I guess the K&N was sucking in the air and the exhaust could not handle the output.

The decat has (touch wood) solved the problem

Thanks again to all that helped.

Big E