92 900S rough at 3000 rpm

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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

--------- 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

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

Thank you.

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

Regards, John

Well, I metered across 1`& 3 on the TPS and have zero conductance until you reach 1/2-way - then between 2300 & 3000 ohms. It looks like time for a new TPS.

Any recommendations for a source? I see that eEuroparts has it for $34.99 and allsaabparts.com has it for 38.

Thanks!

John