Fast idle on an S4 Spider

Squadrone Rosso · #1 (**Post Link**) 03-04-11

Since chaniging the plug HT leads, the car now runs really sweetly but the idle is c1200rpm.

Any ideas on how I slow it down

Cheers,

VeloceMitch · #2 (**Post Link**) 03-04-11

Swap plug leads 3 and 4 round....

Not sure to be hones it's got electronic trickery on it rather than good old carbs

spiderserie4 · #3 (**Post Link**) 03-04-11

On the 89 L-jetrtonic spiders this is done with a couple of nuts on the air intake plenum...but we have Motronic systems and I think this is all run off the ECU. Papajam will no doubt add his decades of experience here

However you could check the idle speed actuator which might be dirty and sticking slightly, this needs a clean up once in a while (carb cleaner or the like)...easy to do. Also check the O-ring it fits into is still sealing and hasn't gone brittle on you. (You should feel the unit feeds into the air intake plenum nice and firmly, and, when removing the clip on the electric plug, it might spring off into no man's land!)
Careful of the small mounting bolt on the bracket (loosen to remove unit) and don't overtighten it, as it goes into very soft aluminium and you do not want to pull the threads out!

crikey_spud · #4 (**Post Link**) 03-04-11

you might have an air leak somewhere, check your vacuum hoses, you might have disturbed one whilst changing your leads.

Squadrone Rosso · #5 (**Post Link**) 03-04-11

Thanks folks

Another job for later in the week

So much for not being allowed to bend over

Squadrone Rosso · #6 (**Post Link**) 07-04-11

Couldn't get the valve off as didn't have a suitable Allen key wrench to undo the bolt.

I took the hose off & squirted a load of carb cleaner into it (I reckoned I must have filled it

).

Reconnected it & did up the bolts. The car cranked for a while before starting with a puff of smoke. Took it for a good blast & all seems good again

Thanks for the advice

spiderserie4 · #7 (**Post Link**) 07-04-11

good news, glad it worked out! (now you know you need a set of allen keys to add to the toolkit!)
My boot has so many tools in it, there is no room left for luggage!

Squadrone Rosso · #8 (**Post Link**) 07-04-11

Thanks. I've got Allen keys but couldn't get the leverage needed to undo the bolt.

I need one that fits on a socket wrench

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