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2003 9-5 Aero Sedan
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Discussion Starter #1
Are you guys ready for the dumbest question you'll read today?

How do you check the timing (with a timing light) on these engines?

Here's the ridiculous part: I've worked on cars since I was 16, including head swaps, head rebuilds, timing belt replacements, suspension work, etc., and I've NEVER had to check timing on any of my vehicles.

This SPG I just got feels like the timing is a bit retarded due to it lugging at low revs (below 2K) and just feeling a bit less than peppy. Given that a previous owner had taken the APC solenoid off the car, and put a manual boost controller on it, I have a feeling said PO may have also retarded the timing a few degrees so he/she could run more boost "safely".

So, walk me through it like I'm a dummy, because when it comes to timing, I am one!

Thanks!
 

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As you know, the flywheel is at the front of the engine bay. There is a small, square window in the black plastic clutch cover that provides a view of the flywheel and timing marks, which are machined onto the side edge of the flywheel. Next to the square hole is a smaller *round* hole: IGNORE it.

The window is hard to see: often, there are hoses in the way, so you may need to work at it a bit to get a view of the window.

Attach your timing light to the battery and clamp the #1 cyl. plug wire, loosen the 13mm bolt that holds the dist. in place, plug the vac. hose line to the vacuum capsule atop the distributor, start the engine, look for the window, and turn on the light. Turn the dist. back/forth to see timing change.

Stock is 16* BTDC. Tighten clamp. Yer done.


If you suspect that the vac. capsule may have been modified to allow more advance during off- and low-boost conditions, then follow these instructions:

Instead of removing the vac. line to the vac. capsule, pressurize the vac. capsule using the pressure nipple on a MityVac or equivalent device. Note I said PRESSURE, not vacuum. You want to move the capsule arm into its "max boost" position by simulating boost pressure.

Now set the timing to 11* BTDC, which is the stock max. retard position. If the car boosts into the red, err on the side of caution and bump it to 10* BTDC.

If you get pinging in light-throttle conditions, use premium fuel, which you should already be using if the car has no APC. Consider re-installing APC, too.
 

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Registered
2003 9-5 Aero Sedan
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60 Posts
Discussion Starter #3
As you know, the flywheel is at the front of the engine bay. There is a small, square window in the black plastic clutch cover that provides a view of the flywheel and timing marks, which are machined onto the side edge of the flywheel. Next to the square hole is a smaller *round* hole: IGNORE it.

The window is hard to see: often, there are hoses in the way, so you may need to work at it a bit to get a view of the window.

Attach your timing light to the battery and clamp the #1 cyl. plug wire, loosen the 13mm bolt that holds the dist. in place, plug the vac. hose line to the vacuum capsule atop the distributor, start the engine, look for the window, and turn on the light. Turn the dist. back/forth to see timing change.

Stock is 16* BTDC. Tighten clamp. Yer done.


If you suspect that the vac. capsule may have been modified to allow more advance during off- and low-boost conditions, then follow these instructions:

Instead of removing the vac. line to the vac. capsule, pressurize the vac. capsule using the pressure nipple on a MityVac or equivalent device. Note I said PRESSURE, not vacuum. You want to move the capsule arm into its "max boost" position by simulating boost pressure.

Now set the timing to 11* BTDC, which is the stock max. retard position. If the car boosts into the red, err on the side of caution and bump it to 10* BTDC.

If you get pinging in light-throttle conditions, use premium fuel, which you should already be using if the car has no APC. Consider re-installing APC, too.
WOW! Great walkthrough, thanks so much for taking the time to write that up!

Now, I'm only seeing about 2-3 psi of boost right now, as I believe the wastegate can may be shot, so you can kinda see my concern about the timing being too retarded.

Thanks so much, I'll check that this weekend (when I check my wastegate) and hopefully get it running in tip top shape! And I'm planning on reinstalling the APC solenoid and hooking it all back up. I just have to find one that fits my budget. Why can't we have any 900Ts in the local Pull A Part? :(
 

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APC re-fit would be a really good idea. I have a friend with a lot of used c900 stuff. PM me if interested and I'll put you in touch with him re: a used solenoid, which he should have.

Once you've got that on, set base boost to middle of yellow. (For a Saab 900 Turbo, "base boost" is the wastegate opening pressure, not the max boost. Note that this applies to cars with APC!) If you are using hi-grade fuel, set it a hair high of middle. Makes the car a lot more responsive. Base boost is very often low on a used Saab.
 
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