355 sticking throttle problem

See if this occurs with the engine off, apply full throttle pedal and let it snap back, if there is sticking present it is related to pedal cables or linkage. If not present proceed. With engine running determine if the throttle sticks closed after a high rpm deceleration usually a 4,000-5,000 RPM 2nd gear deceleration works well, if the throttle sticks you have one or more throttle plates binding in the bore under high vacuum closed throttle. The plates will need cleaning and centering and a proper throttle balance done. This is common to the 355 but easily fixed even if it is a little time consuming. Good luck.

 

It is 100% the cable or linkage.

 

The problem with the throttle tower lies within the spindle/quadrant. There was also a modified quadrant retro-fitted. You need to strip it down and clean and lubricate it properly. Spraying WD40 at it won't do much. Conversely, you should check the throttle cable for fraying at either end as well as the pedal pivot point...
This is a quote from another member that helped with mine...you know back in the day.. :>)

 

Well I got into this tonight. The cable is fine. The issue is the needle bearings in the bell crank, the upper was ok (not great) and the lower was very corroded.

I ordered new bearings from Ricambi this evening and hope to reassemble and drive Saturday.

Will post pictures later.

PS, was emailing with my good friend DrBob and he called it, he was right on the money.

 

Here are some photos, not great
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It helps to own a shop...gage pin used to press out old bearings
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Hello All,

I have a different issue in regard to sticky throttle.

I have what I would describe as an on/off issue with my pedal. If I let off the gas, and then go back on, it is pretty jerky. I have read about a vacuum differential causing this due to the throttle bodies being dirty and the air gap not being correct due to the build up.

Has anyone had this issue and/or confirmation of this issue?

Thanks

 

Mine did exactly that, and it was mostly bad motor mounts causing it. Does your car do this mainly when cruising and not driving fast?

 

I would say that it does it all the time for the most part. It occurs any time that I go from off throttle to on. The pedal feels like it has an initial stick and then it goes. Everything is smooth with engine off and I have gone through all of the issues that are common to sticking throttle.

I definitely don't have a throttle stick, it just feels like an on/off switch rather than a smooth transition from off throttle to on. I drove a friend's 355 and he does not have this issue and his pedal doesn't feel nearly as heavy as mine.

 

I had my QC inspector and master of the camera phone shoot these thru one of our microscopes - you can see how bad the bearing was...

That is not dirt - it's rust...
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Dave that doesnt look like any amount of lubricant would change things there. I do think that if you have this issue we all have it to s degree. Mositure on top of the block that evaporates and steams could be a possiblility

Can someone please explain what the spindle/quadrant is?

 

When I reassemble - I'm going to pack the needle bearing cages with grease. The problem is, the design has no seals and without seals, the grease can get washed out over time...

 

Go Dave Go!!!!!!

 

What about a miniature cap like the swimmers use for their heads? Could we put one on the spindles? lmao

 

New bearings installed
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Done. About 3 hours total, one to find the nut I dropped. I even put a rag under to catch any dropped parts (which it did), then I dropped it from the rag...
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Did it solve the problem?

 

Yes Kevin, it's fixed