Hey everyone,

My friend asked me to have a look at her car which is a 1.4 petrol 01 Fabia. She says is is running very poorly when started, either hot or cold. It only lasts for a bit but the power is very intermittant. I thought it was a carb so I said I'd have a look at it but it's injection. I'm going to change the filters but I heard that you should also clean the throttle body and reset it. Can anyone tell me what that involves and if I need a diagnositic machine to reset them. Is the throttle body 4 butterfly valves like an inline 4 bike engine, and by reseting do they mean balancing. I'd like to save her as much cash as I can and narrow down the problem as I know it could be a bad MAF aswell. I'll also look for any broken pipes.

If anyone could give me any info on it I'd appreciate it.

Cheers,

Tim.

My money would be on a sensor. Where in the UK are you ? someone with diagnostic software (vag-com) may be near you.

Is the throttle body 4 butterfly valves like an inline 4 bike engine' date=' and by reseting do they mean balancing.

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no, it's only got one throttle body unike the majority of in-line bike engines and therefore dont need balancing. also there is no cable because it is servo controlled(drive by wire)

if you are going to clean the throttle body then be very very carefull and dont use anything sharp or abrasive. use somthing like brake cleaner or carb cleaner aerosol cans. also dont try to force open the butterfly because this can damage the servo and a new throttle body is very expensive.

Cheers for that guys. Is there any quick way to open the butterfly, is it spring loaded? Is the best way into it by disconnecting the air filter housing. Can I reach the body with my finger?. Does the gunk build up by the bottom of the butterfly? Can it be clearly seen?

Sorry about all the questions. Last one. Is there any links to sites on the web where i can get my hands on a schematic.

Thanks again for your help.

Tim.

You have to do the following:

take off the airbox

take off the dome over the throttle body ( its beeing hold by 4 spline bolts which you must be careful while unscrewing since they go into aluminium, if you see big resistance, try knocking them first gently)

Now, you can do it in place: clean with aerosol can with the engine stopped and started (somebody hold the pedal down- throttle is open and you spray) or you can take the body off, but have another paper gasket handy it might brake.

The normal position is slightly open, not perfectly close so the engine can breathe at idle. Because of oil vapors comming from the crankcase breather the throttle is obturated arround its idle position and the engine "suffocates" at idle. The ECU corrects this by opening the throttle when the engine is "dying", that's why you should see it reving from time to time by itself.

check out some of my pics:

http://vwforum.vwforum.ro/index.php?act=Attach&type=post&id=719

http://vwforum.vwforum.ro/index.php?act=Attach&type=post&id=720

http://vwforum.vwforum.ro/index.php?act=Attach&type=post&id=721

http://vwforum.vwforum.ro/index.php?act=Attach&type=post&id=722

there is the 8v throttle, you can see where the dome(not present in the pics) is bolted.

hope this helps.

Thanks very much for that. I'm still unsure though about opening the throttle when I'm cleaning. Are you suggesting running the engine with the box off and get someone to press the pedal and just cleaning while the engine runs, or will the throttle open when the pedal is pressed with just the ignition turned on and the engine not running.

I'm just a bit wary of wiping it with paper towelling while it is intaking air.

That's my last question, honest.

I'd still agree with Phil and say the fault is more than likely down to a faulty coolant temp sensor.

Thanks for all the help folks. Especially the pics Akebono. Cleaned it this morning and it's running like a new car again.

Tim.

Thanks for all the help folks. Especially the pics Akebono. Cleaned it this morning and it's running like a new car again.

Tim.

Sorry to drag this post back up, but I'm in the process of cleaning out ours. How did you get it to open without running the engine?

not sure on the fabia, but most other petrol throttle bodies I've come across have a spring loaded rotating wheel on the side of the throttle body. To open the buttefly valve - you can just twist it with your hand. This is handy when you're running the engine and want to rev the engine under the bonnet. You can do this when the engine is off. Alternatively - you could wedge the throttle down with a stick in the driver footwell.

Be very careful - it is easy to damage the butterfly valve. Use loads of pipe cleaners/cotton buds & plenty of carb cleaner/any other degreaser. Try and clean as best you can.

Also check the pipes that connect up to the induction tube (from the air filter). these can get clogged with oil (think it's an oil breather pipe).

Have fun, D

No there isn't a spring loaded wheel as it's drive by wire so you can't twist it by hand like you can on throttle cable controlled cars. I just got my friend to rev it and cleaned it as he did. I used carb cleaner mixed with 5 parts petrol to 1 carb cleaner. I read in a few places that the carb cleaner is rough and can age the rubber seals on the spindle of the butterfly if it's too concentrate. Then just used a toothbrush. I found the scum was on the butterfly itself and came off quite easy. It did the job fine. (We racked our heads on how to open it but barring revving it wide open and pulling off the connecter or sending a signal from a function generator to replicate the duty - too much time on our hands) but the tootbrush and buddy with a foot on the pedal giving it a good rev worked fine.

Best of luck with it.

Forgot it's fly by wire!!! Does it work without the engine on (does it open without the engine on).

Good idea to dilute it - that stuff neat can damage the cat.

Toothbrush - an essential in the tool box!!!

D

No it doesn't open without the engine running, it is controlled by the pot on the throttle and the feedback from the ECU, so even with the engine running on high revs it still doesn't open anywhere near what you could open the throttle by pulling a cable. So it's not as easy as just turning on the ignition without running the engine and putting the foot to the floor, as I said though, there seems to be plenty of room to clean what I needed. Best of luck.

Tim.