[V8] Engine Still Not Running Smoothly ...

[Jason Wilkerson]

When I first bought my v8 there is a frequency valve under the passenger front fender - it had a rip in the diaphram - made a hissing sound.  Also, I've seen the hose going to the FPR rip and do the same thing.  Worth a look.

--- On Sat, 11/7/09, urq <urq at pacbell.net> wrote:

> From: urq <urq at pacbell.net>
> Subject: Re: [V8] Engine Still Not Running Smoothly ...
> To: "'V8 list'" <v8 at audifans.com>
> Date: Saturday, November 7, 2009, 9:01 PM
> When I got the engine back together I
> left the big cover that holds the air
> filter in place off (the air filter was installed). 
> The engine does seem to
> run more smoothly … perhaps due to the fact I had to mess
> with ¾ of the
> spark plug wires when I pulled the distributor.  I’m
> still thinking the
> engine is a bit down on power compared to the other car …
> but perhaps this
> is due to the cams from the automatic engine … 
> 
>  
> 
> As those who have pulled this cover know, the engine intake
> sounds are much
> more audible with the cover removed.  One thing I
> noticed was that I could
> hear a variable hissing at idle.  I’m thinking it is
> the ISV, and perhaps a
> sticky ISV … but it did seem to cause a bit of rough
> running.  I
> disconnected the ISV and kept the engine running by
> cracking the throttle a
> bit, no hissing.  
> 
>  
> 
> I’m going to use the carb cleaner method to see if the
> ISV is sticky, but if
> any others out there have had to deal with similar issues
> and have something
> to share I’ll appreciate hearing from you!
> 
>  
> 
> Steve Buchholz
> 
>  
> 
>  
> 
> … in preparation for the smog inspection I went through
> and did a
> replacement of the spark plugs, dizzy caps and rotors in #2
> … 
> 
>  
> 
> The “new” engine I installed a few years ago has always
> run a bit rough for
> a V8 IMO.  I had imagined that there was something
> wrong inside a combustion
> chamber or some such … well, since I had all the spark
> plugs out I did a
> compression check … the first measurement on #4 was
> ~120PSI, considerably
> lower than the ~160PSI I saw on the other cylinders … but
> then since that
> was the first pot I tested I decided to go back and check
> again later …
> compression was now up with the rest of them.  I
> verified that each cylinder
> was firing by pulling the plug wires off, each one seemed
> to have a
> consistent effect on the idle speed and smoothness of the
> engine.  I started
> to convince myself that the engine was running smoother
> with the new bits
> installed … then I thought to fire up #344 in the
> adjoining bay … smooth as
> silk … 
> 
>  
> 
> The engine in #2 is an automatic variant, but I can’t
> imagine that would
> make a difference in smoothness of the engine.  I
> wouldn’t imagine bolting a
> flywheel on the crank would have imbalanced it in any way
> (it was a brand
> new flywheel).  This engine also seems to be down on
> power compared to #344.
> I thought I’d toss this out to see if there are any
> hypotheses out there on
> what may be going on.  The ECU shows no fault
> codes.  I’ve got the set of
> injectors sitting on the PT in the garage … I may try
> running them to see if
> it makes a difference.  
> 
>  
> 
> While I found some plugs to be in better condition than
> others, the exhaust
> does not have a strong hydrocarbon smell when the engine is
> warmed up and
> running … in fact it seemed clean enough that the car
> would likely have
> passed the test as is … I just like to have a bit of
> margin … and the
> ignition parts are the ones that came with the engine …
> in fact I had to
> break the old rotors off with a vise grip … 
> 
>  
> 
> Steve Buchholz
> 
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