355 sticking throttle issue on cold start up, car redlines

[RetroTed]

Hi all, hoping someone will know the answer to this

Our 355 is normally a display piece, however on the odd occasion it's started it appears to randomly rev to the redline by itself from cold start up. I've looked at the throttle cables and the throttle housing and everything seems fine. If you push the throttle pedal half a dozen times before start up it's fine and it doesn't do it when driving

Weirdly the throttle is spring loaded so I don't see how it's revving by itself ??

Any ideas please

[EVOeng]

Possibly pedal pivot bush, gets stuck with old hard grease. Best to disassemble, clean, regrease and put it all back together.

[RetroTed]

Hi
Thanks for the comment. The throttle pedal is in the normal position when we start the car so it should just tick over as normal

It's like the throttle is being held wide open without touching the throttle ??

[Bispal]

Sticky throttle cable. Grease inside is old and gone hard. You need a new throttle cable. If you are in the South East speak to Dan Mayo at MMS Technik. He did mine on my drive at home.

[Thom]

The throttle cable must be routed correctly in between the hoses to the water pump or it may not slide freely inside its sheath and that can make the sticky pedal effect worse.
It sounds like the whole mechanism needs a thorough clean up, between the pedal box, the cable and even perhaps the throttle bodies.

[M138]

Not sure if a Ferrari 355 has a throttle potentiometer but when it went on my Maserati 4200 that revd high on start up.

[RetroTed]

Thom said:

The throttle cable must be routed correctly in between the hoses to the water pump or it may not slide freely inside its sheath and that can make the sticky pedal effect worse.
It sounds like the whole mechanism needs a thorough clean up, between the pedal box, the cable and even perhaps the throttle bodies.

Hi Thom and thanks for your response. My issue that i'm struggling with is, the car ticks over lovely when we park it up at night. Nothing sticking and all is well. When we come to it in the morning it sometimes redlines when we start it up without touching any pedals at all so and this is why i'm scratching my head

[ex-devonpaul]

If it is OK UNLESS you press the throttle, then I can't see how a sticking throttle would cause it as you'd need to open it somehow.

Perhaps the Air Control Valve that controls fast idle - plenty around like Ebay item 332395612825

[F355GTS]

Carpet mats fouling the floor mounted pedal are a known problem

[Bispal]

Why don't you take it to a specialist.

[RetroTed]

Bispal said:

Why don't you take it to a specialist.

Because you have to wait weeks to book in, it costs a fortune and I like to fettle with stuff

[Bispal]

RetroTed said:

Bispal said:

Why don't you take it to a specialist.

Because you have to wait weeks to book in, it costs a fortune and I like to fettle with stuff

I did post details of one who will come to your house and you're not having much luck self diagnosing.