[V8] Stumbling / surging problem

[cobram at juno.com]

You might want to check the engine reference sender(s).  After warmed up
it might be closing a fault in the sensor or the wire, when cold it might
be throwing an intermittent signal.  They usually fail in one shot (car
just won't start), or with the car hot (dies and have to wait for it to
cool a bit to get going again -hi Ed), but I have seen ONE that was
failing when cold.
"Fairly new O2 sensor" would also warrant a good check of the reference
sender plugs.
Also, make sure that you've got the TPS adjusted correctly, it too can
cause your symptoms.

BCNU,
http://www.geocities.com/cobramsri/
Health is merely the slowest possible rate at which one can die.
 
"David Lyddall" <david at styletrack401k.com> writes:
> Has anyone come across a problem like this one:
> 
>  
> 
> I have a black '90 V8q auto, and when it's cold, it drives like it 
> is
> running out of gas.  It idles fine, but at partial throttle it 
> really feels
> like it's starving of fuel.  When it does this, you can floor it and 
> it will
> get up and go, although it feels a little short on power.
> 
>  
> 
> Here's the list of things I've tried - I double checked that the 
> timing is
> correct - it was off a couple of teeth on the cams, but it is fine 
> now.  It
> has a new fuel pump - the old one was wining like crazy, but that 
> wasn't the
> problem.
> 
>  
> 
> It feels like a bad mass air flow meter - bogging down under 
> partial
> throttle, but I switched the one out of my other V8q and it made no
> difference.  Also tried switching the TPS, but made no change 
> either.
> 
>  
> 
> It has a fairly new oxygen sensor, so I think that is unlikely to be 
> the
> problem.
> 
>  
> 
> Before I got the car it had sat for about 3 years, so the fuel 
> system was
> full of varnish.  It does have a new fuel filter, but I wonder if 
> maybe the
> fuel pressure regulator is causing trouble.
> 
>  
> 
> Any ideas would be appreciated - I really would like to make this 
> car run
> right.  I've been using it as a loaner car at my shop, and it gets 
> old
> explaining to people what they need to do when it dies on them.
> 
>  
> 
> Thanks
> 
>  
> 
> Dave
> 
>  
> 
> 90 v8q x2
> 
> 96 a6w