Ferrari Mailing List: Re: 328 fast idle question--hit a bump?-reply

[Doug and Terri Anderson (dnt]

Sounds nice Robert - um, the plenum is the big ribbed aluminum air box atop 
the intake trumpets.  Center of the engine bay with the big 3 inch air hose 
going to it from the CIS fuel metering device.

There are two hoses, I believe, coming off the left side and one big one 
from the front.  This front one goes to the additional air valve - [left 
side and used at warm up time - at the front - front is towards front of 
car - of the plenum is also a fuel hose from the injector distributor.  This 
spritzer should have a wire going to it.  When first starting up the fuel 
gizmo receives a signal to richen up the fuel mixture and it spritzes fuel 
into the plenum - a very rich mixture - and the air valve allows additional 
air in to make up the correct mixture.  As the engine warms up the 
additional air valve closes off.  Sayyy - the air valve should have a wire 
going to it too - make sure it is firmly attached]

Sometimes, on a CIS engine, a loose oil filler cap will cause the engine to 
hunt - so will a loose dip stick.  Tho it doesn't sound as if this is your 
problem.

This year CIS should have all sorts of rubber hoses - and as one fellow 
lister, Ed, said they are 20 years old, probably pretty stiff lot. 
Therefore prone to crackage (highly technical term).  Just follow each hose 
with your hands and lightly tug and wiggle.  I have pictures of hoses nested 
way down in the engine that had the bottom crack off in big elliptical moon. 
Ayep - two pieces.

This outcome happened as a result of a shock event - what ever it is - the 
culprit was probably just waiting to surprise you.

Onward and keep us informed.
DOUG

----- Original Message ----- 
From: "Robert Rehkopf" <CaptRehkopf [at] Comcast.net>
To: "'Doug and Terri Anderson'" <dnt [at] dock.net>
Cc: "'The FerrariList'" <ferrari [at] ferrarilist.com>
Sent: Saturday, September 27, 2008 12:51 PM
Subject: RE: [Ferrari] 328 fast idle question--hit a bump?-reply


> Doug.
>
> 1988.5 vin 77688, full service by Norwood about 1500 miles ago, about 
> 10-15
> mph. I thought my plenum was on the passenger side?
>
> Thanks,
>
> Robert Rehkopf.
>
> > > Robert pleads "So now that I have done all I know to do somebody please
> > > give me some professional advice!"
>
> Hey Robert - asking for professional advice from this group is akin to
> asking Ferrari Bubba to explain why he didn't become that piano player at
> the Mustang Ranch.  heh heh
>
> Nevertheless - here goes: Need some more data - how old is the car?  Last
> service?  How fast did you hit the bump?
>
> The CIS induction system is very very basic mechanical fuel injection.  It
> gets its enrichening signal from a balance beam teeter totter affair
> activated by the down draft volume of air requested on the air horn 
> paddle.
> Too much unmetered air and it quits, too much fuel and it runs like a 
> slug.
> So, that said - I would vote for too much air.  A vacuum line fell off.
> Perchance from the "body, air delivery" [I'd say air plenum chamber - 
> guess
> it doesn't translate well] drivers side (if you are a LHD car).
>
> Gimmie more info.
>
> DOUG