Sticking throttle S1

[AlfaSpider]

Hi
I'm struggling with a sticking throttle and how to fix it. The cable is free and lubricated and returns ok with the engine off, however with it running its holding up taking a few seconds to return, I'm going to strip and clean the throttle body next see if this helps. Has anyone else come across this problem on the 2.8?

[TVRees]

Cleaning up everything is a good idea.
Maybe a cable return spring has come loose and check that it's not sticking in the footwell...... on the carpet maybe

[GreenV8S]

Check your assumption that the throttle spindle itself is physically sticking open when the problem happens - from your description, I'd suspect it might be an idle speed control issue instead.

[AlfaSpider]

I tried fitting a stronger return spring which possibly helped to start with but now it's happening all the time. The pedal stays depressed and slowly comes back, as it's a cable I can't hook the pedal back with my foot to stop it revving. I'll have a go at cleaning it.

[glenrobbo]

Check the throttle plate pivot is nice and free, I found it was starting to seize in my S1. Strip it, give it a good clean up and lubricate it with anti- seize grease.

Also make sure that if you have under-bonnet insulation that it is not coming unstuck, dropping down, and fouling the throttle linkage.

Finally make sure that your throttle cable has no frayed strands and is free to move inside the outer sheath.

[greymrj]

Easy to check which it is. Quick disconnect of the throttle cable at the throttle lever. Try rev by hand. Almost certainly the cable if it is holding the pedal back. Out with the cable, awkward but not difficult and really define the problem. If, as Glen suggests, a cable is fraying you MUST replace it or a sudden stuck throttle could mean the end of a good S...and you as well!!!

[GreenV8S]

Does it still happen when the bonnet is open?

[AlfaSpider]

With the cable disconnected it feels free as does the throttle mechanism. It's odd because the pedal returns fine as soon as the engine stops. I'll try it again with the cable disconnected and engine running. I can only think the vacuum with the throttle almost closed is loading up the throttle pivot slightly.

[AlfaSpider]

I tried stripping and cleaning everything but it was still sticking until I removed the carpet and now it's fine. I should have tried that first perhaps! Thanks for all the advice.

[GreenV8S]

Fit a pedal stop while you're thinking about it.