Saab: 92 900S rough at 3000 rpm

John Anderson wrote: 

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Is this an manual or auto? I have a similar issue w/a 91 900S 5spd (also
LH 2.4.2), that has been to two master Saab techs w/o resolve. I'm
attempting DIY. I can provide some suggestions, pending if you want to
DIY and/or what tools you have

Have you checked your Throttle Position Sensor for drop-out?

Lance

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alancemor....AT..yahoo.....DOT...com

LanceM wrote:

{snip} 
Is this an manual or auto? I have a similar issue w/a 91 900S 5spd (also
LH 2.4.2), that has been to two master Saab techs w/o resolve. I'm
attempting DIY. I can provide some suggestions, pending if you want to
DIY and/or what tools you have

Have you checked your Throttle Position Sensor for drop-out?

Lance

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It is a 5-speed.

I am fairly competent around an auto - I don't have any special
tools (exepct for the gearshift housing tool) for the SAAB.

How do you check the Throttle Position Sensor for drop-out?

Regards,
John

John Anderson wrote:

<snip>
 

You'll need something like a multimeter to measure resistance. Remove
TPS conn harness at TB. One probe on terminal 1, other on terminal 3 (of
TPS itself, not the wiring). Completely open or close the throttle _very
slowly_. Should see continuously variable ~1100 - 3000 ohms resistance,
w/o any drop-outs.

Can more definitively ck voltage: steady power, variable signal, and
ground at TPS and ECU, w/an oscilloscope (above is fairly good, tho)

Alternatively, can get another TPS new or used (Bosch PN is on TPS, and
the exact same part is used on _lots_ of early 90s imports)

Bentley service manual highly recommended for DIY

Lance

--

alancemor....AT..yahoo.....DOT...com

LanceM wrote:
 
Thank you.


I have the Bentley and will be investigating this week. I will post
results.

Regards,
John