History:
1993 9000CSE 2.3turbo
replaced 212K engine with 140K engine.
kept original manual transmission (140k motor was from an auto)

OK so. It runs. It has a funny idle (will run awesome until engine warms up a bit, then it will die, or almost die, then runs betweehn 900-1000 with an up/down oscillation.) but the old engine did the same thing.

here it is: the turbo wont spool up past touching the yellow.

it has gobs of smooth low rpm power (fine for getting around, it goes down the road nice), but then when you step on the gas, i can feel and see the turbo kicks in until it gets to mid-low boost, then stays there. (is this the limp-home-mode?)

then first weird thing is the pedal firms up a lot. you can force it down by pressing against the resistance, but it doesnt give you any more power. (previously i've had the same feeling when driving up a big hill in 5th gear and giving it more gas instead of downshifting to 4th, not sure if it's related though.)

the other weird thing is that when it's idling the throttle cable is at at least 1/2 throttle. when you unplug a vacuum line, it goes all the way back to the 'no-throttle' and idles a bit better. but then when you drive it with a line unplugged, you get the 'hard throttle' all the time.

I hear a great sucking noise when you're giving it as much gas as it'll take and i dont hear the blow-off valve when I let off the gas.

oh, and i havent checked codes since the replacement.

thoughts?

one more thing, the 140K motor has one more wiring harness than the original 212K motor. hmmm?

Thanks,
-Owen

Hi, and welcome to Saabscene.

First off, was there anything wrong with the old engine that made you decide on the engine change? Sounds a bit on the drastic side.

You're only in yellow because you're probably running base boost only. This indicates that the solenoid valve has failed and you'll need a replacement. As this is not engine mounted I'd suspect the problem(s?) would be carried over to the replacment engine.
I would also suspect incorrect plumbing to said unit.

Strange up/down idling could be an issue with the MAP sensor (I know some 9000's had them) also not an engine-mounted item so problem also carried over to replacement engine.

Do you have cruise control? I think on your model this would have been vacuum actuated so perhaps some crossed tubes here as well.

Extra wiring harness? TCS, perhaps? (TCS = traction control) -> may also be attached to throttle body... and perhaps mismatched to ECU?

You won't hear the blow-off valve as the engine is not under load therefore no boost.

Just some thoughts, I'm answering because I'm in a different time zone than most of the members and own a 900SE, but some observations could be applicable.

I'm sure someone will be along later who can offer greater insights as to your plight.

Hope it works out.

Vincent in Bangkok

Could be a lot of things from TCS doing it's dreaded Limp home routine OR more likely the ...Wrong... motor version being retrofitted.
Not just any 2.3 can be retrofitted.
The later engines 95(?) on had a different technology Crank Position sensor. IF one of those then yer in trouble.
Earlier one was positioned externally at the Belt pulley end of the motor while the later version was inside the engine block at the flywheel end of the crankshaft. Others have cobbled up the newer design Sensor to work on the old style pulley located one (as in your 93) .
Doable but not child's play either.