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This B20B in stock form was way out of whack in the timing/idle department.
Idling at 1700 RPM!
Jay at Yankee Trading said I needed to loosen the distributor and adjust the timing to retard it some, which would bring down the RPMs. Also, the idle set screws were backed off to the point of no contact on the cams, thereby leaving the throttle plates open to the wrong side of closed, if you follow that meaning.
Man! The timing was so far advanced wasn't even on the scale! then, everytime I tried to put even 10 degrees *advanced* (as close to getting it on the scale which slowed things to reasonable idle), it would take off own its own back up to 1700 RPM
Next day at the Carlisle Import Show I talked with a couple of guys, including a SAAB freak.
So, I did the following:
To assure the distributor was installed correctly, or not, I removed #1 Spark plug and found TDC on that piston's compression stroke. then I confirmed the crank pully timing scale was at TDC. It was.
So I pulled off the distributor cap. Found the rotor was way past #1 position. So I turned the distributor body to line up the rotor in line between #1 and #4 contact posts, making it complete the #1 circuit dead on.
Upon starting the engine, it idled at 1700 again. So I set the timing to 10 degrees BTDC, which, I was told is spec (Haynes *alludes* to -5 degrees)
At least now I could focus away from the timing and look into the carbs as the source of the problem.
I lubed the linkage joints first. Inspected the action. All good.
Then I noticed one of the 2" vacuum lines off the front float chamber appeared cracked. Yeah, at both ends!
Replaced this and now got revs down about 500 RPMs to 1200
OK, what else is the matter?
I know my choke cables don't keep still nor "shut off" choke completely, so while investigating them, I noticed the front set screw under the cam wasn't even touching the cam. Well, that would lessen idle, not raise it.
On the rear carb, though, this set screw was touching. It was actually holding the choke on, in fact.
After backing it off the cam, the idle came down to 900
From there is was a mater of fine-tuning the idle set screws on each carb. (This is the first time they could actually adjust anything, with some "room" to back off even)
Got things to about 825 with about 25 RPM fluctuation.
I'm not done yet, as the car will idle noticably slower when started and left alone, versus revved and left to settle. So I will consider weaknesses in linkage, other minor air intake leaks, etc.
The moral(s) is/are:
Don't assume anything is right until you verify that it is. (Don't assume, as I did, that the vac hoses were good)
Always look for the basic, simple, fundamental things. I believe 99% of expensive parts-swapping-type reapairs were money wasted due to sloppy attention to simple details which should have been caught.
Pay attention. Be thorough. Assume nothing. Verify all.
Sign me,
"Very Satisfied in Easton, PA"
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