[200q20v] hesitation, hiccup revisited...new clues

[Brett Dikeman]

On Mon, 4 Jun 2001 Tresturbos at aol.com wrote:

> Hi list,
>
> A couple of months ago I wrote about some hesitation or jerkiness under
> medium to low throttle at no particular point along the rpm band (not just
> down low, I ain't no lugger :-)

I get:
-rough startup(ie, can't be driven for about 15-20 seconds or it'll bog
down; possibly subsiding with the use of techron, but hard to tell;
only happens in warm weather)

-jerking at very, very slight throttle(not dependent upon RPM,
most noticable in 1-3rd.)  There's a spot on the throttle where the car
will just jerk continuously if you leave it there.  Makes stop and go
traffic incredibly annoying.

-slow-to-build boost, and uneven acceleration at highway speeds(initial
surge, slight hesitation, then builds back up, if you floor it.  This
tends to disappear with long periods of calm driving; if I drive, say, two
hours calmly, the car will be greased lightning the remainder of the
trip.)

My current suspect is either a vacuum leak or a FPR problem.  I once
checked the hose to the FPR by inducing a vacuum in the hose to the FPR,
and the mityvac sucked out air which smelled strongly of gasolene.  I'm
going to try and find any vacuum leaks tonight with the help of a
rubbermaid container(the little teeny bowls are the -perfect- size to
plug the boot that normally attaches to the MAF sensor!) and a air
compressor...we have a couple gallon storage tank that feeds an
adjustable pressure regulator, so I should be able to listen for leaks
with ease.

I'm also going to ask Shine Racing to take a peek around if they have time
tomorrow; the Big Baby's going in to have the shocks+struts
installed(finally.)


Brett