Handy tip for Renix injection systems TPS adjustment.

My 89 XJ wasn't shifting right (AW-4 auto) and neither the instructions in
my Chiltons or my Haynes manuals seemed to work for setting the TPS.

But I remembered reading about another method using a percentile of the
measured supply voltage (across the grey and black wires at the connector to
the TPS).

So, with my trusty calculator and the numbers from the manual I figured the
percentage needed ...16% of the supply voltage.

Since my system didn't measure a full 5 volts (4.85 V), I adjusted for
0.77-0.78 volts output from the TPS, then I disconnected the battery for 30
seconds to reset the computer.

Now the trans shifts perfectly and the engine runs better.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:
> My 89 XJ wasn't shifting right (AW-4 auto) and neither the
> instructions in my Chiltons or my Haynes manuals seemed to work for setting the TPS.
>
> But I remembered reading about another method using a percentile of
> the measured supply voltage (across the grey and black wires at the
> connector to the TPS).
>
> So, with my trusty calculator and the numbers from the manual I
> figured the percentage needed ...16% of the supply voltage.
>
> Since my system didn't measure a full 5 volts (4.85 V), I adjusted for
> 0.77-0.78 volts output from the TPS, then I disconnected the battery
> for 30 seconds to reset the computer.
>
> Now the trans shifts perfectly and the engine runs better.
>
> Budd

Interesting aproach.
Alas my tps is fixed in the ZJ, so the problem is almost always
a wear-spot somewhere right at light pedal on the highway.
Causes the transmission to downshift or hiccup between gears!
And the real _bitch_ is the TPS tests just fine.... Even for
a 93, these sensors are twitchy.

--
DougW

DougW wrote:

> Interesting aproach.
> Alas my tps is fixed in the ZJ, so the problem is almost always
> a wear-spot somewhere right at light pedal on the highway.
> Causes the transmission to downshift or hiccup between gears!
> And the real _bitch_ is the TPS tests just fine.... Even for
> a 93, these sensors are twitchy.

That's when I flood the !@#$%^& sensor with WD40 and work the throttle back
and forth a bunch of times. WD40 is NOT primarily a cleaner but it works
pretty well on mechanical contacts like rheostats and connectors - just blow
things as dry as you can when done. You can force the stuff into the
housing if you spray it close to the shaft. Been "servicing" my TPS that
way for years.

--
Will Honea