The Old Throttle Response Delay

When L8APEXER posted his impressions of driving his 355 over the first several miles of new ownership, one of the issues he cited was, "poor throttle modulation." I believe that we have all suffered through that difficulty, so I took one responders advice and worked on my gas pedal a bit.

When I removed the plastic cover from the floor, I found a huge pile of carpet remnants and general crud around the throttle pivot points. After wiping off all I could with a rag, I dutifully vacuumed the heck out of the area and finally used some silicone spray lubricant to loosen the binding. I'm not sure how long the fix will last, but I gotta tell you that the difference in throttle response was immediate. No more drag or hesitation at the first few millimeters of pressing on the gas.

So I appreciate the guidance from my FCHAT brothers and look forward to many miles of less-strained driving in the future.

Cheers, Henry

 

I tried this. Granted, the surrounding area on mine was fairly clean, but after luring I noticed minimal difference

Was hoping this would help.

 

cool

 

Great fix Henry. This requires adjustment on all out cars every once in a while...

Robb

 

While the initial cleaning and lubrication did some good, it hasn't eliminated the throttle lag that I hoped it would in the long run.

Oh well...

 

Try pushing in the clutch monetarily at low speed.....this will reduce the vacuum/throttle body lag in the throttle bodies.

 

355's have individual throttle bodies

Lotta vacuum there....may need setting up precisely for really smooth break away from idle

 

The difficulty for me is doing a rev matched downshift (gated). After I momentarily release the throttle to disengage the clutch, the resistance makes it hard to blip the throttle.

If I try and blip gently, I don't overcome the resistance and I lose the revs. If I push hard enough to overcome the resistance, I blow past the desired rpm and lord knows the wear the clutch is taking.

 

In my prev F355 the throttle was real laggy and acceleration off the line seemed not as good as before. Turned out the throttle cable had slack and also needed to be lubricated. After this fix, the F355 had much better throttle response.

 

my car a 97, exhibits the exact same thing.
the first time i noticed this was early on when I first got the car a year ago, while performing a rev match downshift.

with my other cars the blip of throttle is seamless
but in the 355 if I put in clutch, let go completely the throttle and then blip it doesn't always act as I want and miss the rev match completely

it is annoying as hell, cause when it happens the exhaust makes like a burp sound

the way at least that i learnt to resolve this is not to let go of throttle during the downshift.
therefore as you put in clutch keep foot on the throttle in same position.
and blip it right away before rpms have a chance to drop.
the outcome is a perfect rev match.

I'll have the cable adjusted when I do my engine out over winter.
hopefully it will improve for a more crisp throttle blip.

but at least my throttle blip technique for now works.

 

Have you matched the throttle opening on both banks? You may want to have a look to see that each throttle linkage is opening the throttles and virtually the exact same time. Which ever linkage is opening the throttles first, match the lagging side to it. I would then disconnect the battery, have the ecu go through relearning the warm up parameters, then take it for a nice calm 30 minute drive.

 

if you mean, if the throttle bodies are in synch?
then yes they are, my mechanic checked this and they are dead on.
he checked when removing all the throttle bodies for a complete cleaning of each one.

 

How mich free play do you guys have, i have a lot

 

Air flow meter will cause this. They get old and act like a carb with a accelerator pump problem. Also cleaning the AFM appears to not work. I replaced mine and the result was amazing. I dont think you get a code for AFM either....

 

Are you talking about the MAF (mass air flow) sensor? Mine is brand new with less than 1,000 miles on it

 

l

No