[V8] Stumbling / surging problem

[dsaad at icehouse.net]

How about doing a "power flush", where a cleaning fluid like the GM Top Engine
Cleaner is run through the fuel injectors for a while using a special machine?
This may clean up the results of the car sitting around for so long.
It also cleans out all the carbon buildup and in general, magically makes your
car like new again.

The symptom sounds like a classic buildup of deposits on the intake valves.


(YMMV :-)

Dave


Quoting David Lyddall <david at styletrack401k.com>:

> 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
>
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