[urq] hesitation, bucking on takeoff - not resolved yet!

Thu Oct 20 02:23:17 EDT 2005

Ben  These are similar symptoms to my mates WR that used to do this. It got
worse until the car was undrivable. Eventually traced to a faulty hall
sender in the distributor. The part is the same as that on the non-turbo
cars I believe (?) and can be swapped so there is no need to buy a whole
distributor.
Good luck

Keith

'87 WR
----- Original Message -----
From: "Ben Swann" <benswann at comcast.net>
To: <DGraber460 at aol.com>; <urq at audifans.com>
Cc: "Ben Swann" <benswann at comcast.net>
Sent: Wednesday, October 19, 2005 5:53 PM
Subject: Re: [urq] hesitation, bucking on takeoff - not resolved yet!

> I am still chasing this problem - '83 UrQ bucking/violent hesitation and
no power when accelerating in first and second gear/from a standstill.
Since the problem began here is what I have done to no avail:
>
> 1.  Checked airfow plate level and adjusted as it appeared a little high -
nope.  Then compared the plate movement to others and noticed it seemed to
be binding a little, and did not bounce when dropped.  I replaced with
another that moved freely.  Still no improvement to my surprise.
>
> 2.  Ran fuel pressure tests as I had been suspecting control pressure too
high.  Tried 3 different WUR/CPR units and am using the one which most
closely matches desired pressure range and operation according to IST doc.
Pressure when cool 65degF is about 23 PSI and warms up within 5 min to 55
PSI where it levels off.  This seems to correspond with the IST range of 1.5
Bar - 4 Bar. The diagram in IST document.however does not map temp and may
not be right.  I noticed the pressure range to be somewhat higher than for
CIS in NA coupe.  The problem occured in the same way regardless - other
regulator range was 22-45 PSI ( WUR from 2.2l NA Coupe) is the one that was
in the car when problem began.  The engine had been running fine for awhile
with this regulator, and the problem occured due to no equipment changes.
>
> 3.  At this point I pulled the injectors.  All seemed to have a marginal
or bad spray pattern, so I broke down and replaced them.  I was sure this
would be it, since when I tested them, the injectors came on
abruptly/sporadically and dribbled. peed sideways or a stright stream.  Yet
after installing them - new injectors and seals, the engine bucks as bad as
ever.  The spray pattern was much better and looked like it should.  At this
point I am getting rather frustrated.
>
> 4. Adjusted duty cycle - have been doing this whenever changing something.
Duty cycle can be adjusted to near 50%, but does not always ocillate around
50%.  Duty cycle does range from 5%-95% under varying conditions, or if I
enrich or enlean by adjustment.  Still I decided to swap out the ECU.  Still
no improvement.
>
> This problem occurs when the car is warmed up, mostly after having driven,
shutdown and restarted, but will happen when driven then hitting traffic.
Car just bucks like crazy when put in gear and given throttle.  Once the car
get going, it drives fine, but in lower gears just does not want to go
without major hesitation.
>
> 5.  Other things replaced in last 6 months/6000 miles:
> Distributor Cap, rotor,  spark plugs and wires, new coil(done after
problem began). O2 sensor new.  All grounds are clean and good connections
to battery.  I continually check for leaks and most of the vacuum lines have
been replaced.
>
> 6. Fuel pump and filters were new about 2 years ago when I brought the car
back from the dead.  Recently changed pre filter and continue to not some
accumulation of residue getting caught by pre-filter.  Pressure is good and
if anything on the high side - pegs my fuel gauge which stops at 60.  Id
guess system pressure is around 90 - using NG pump.  Did not test flow, but
nothing to indicate there is a fuel delivey problem - perhaps I need to
double check.  Does not make sense that the car seems to have full power at
speed, yet not enough to get out of it own way when starting from a
standstill.
>
> So presently I'm at a loss as to what is going on - everything I check or
change seems to make no difference.
>
> Ben
> ----- Original Message -----
>   From: DGraber460 at aol.com
>   To: benswann at comcast.net ; urq at audifans.com
>   Sent: Saturday, September 24, 2005 8:47 PM
>   Subject: Re: [urq] hesitation, bucking on takeoff
>
>
>   In a message dated 9/23/2005 8:05:25 P.M. Mountain Daylight Time,
benswann at comcast.net writes:
>     This problem has gotten progressively worse on my '83.  Earlier this
summer
>     she was running great with no problems except the occasional hard
start.
>     Now, particualarly after warm and mostly after shutting down and
starting
>     after 15 min. or so, the car bucks and hesitates like crazy on takoff,
>     mostly in first gear, if I double clutch it enough to get some
momentum going
>     and shift into a higher gear it'll pull fine and then seems fine at
higher
>     speed or cruising.  It has gotten really annoying as often won't get
out of
>     its own way when taking off at a stoplight.
>
>     I know it is not the fuel pump cutting out.  O2 sensor has been
replaced and
>     attempt at adjusting the mixture make no difference.  The ignition
>     components are new, incl. coil.
>
>     I suspect control pressure, as this happens after it is good and warm.
>     Sometime is hard to start and stalls out after starting fine and then
want
>     stay running without giving the particular magic footwork to the
throttle.
>     I had recently cleaned airflow sensor and filter, and all was right
and it
>     ran good until it started doing this.
>
>     Really strange as it seems to have full power once going over about 7
MPH
>     but off the line bucks like crazy.
>
>     Any ideas or BTDT.
>
>     Thanks,
>
>     Ben
>
>
>   Check and see what your tach does during these episodes. If it drops and
bounces, it is probably an ignition problem. If not, then fuel is the
culprit. Do you have a fuel pressure gauge?
>
>   Dennis
>   Denver
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