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Hello Saabs,
I have an 1988 SPG that's been on blocks since 2002. Finally of blocks and in my garage. While on blocks, I fired up the motor about every month. Back in 2002, it started up immediately every time. A few years ago, it would intermittently refuse to start, and that's how it is now. To be clear, by start I mean fire up. The starter motor spins the engine just fine.
Details:
The gas in the tank is "on average" about 1 year old. I keep it at about 1/4 full. I've added gas line dryer and valve cleaner additives, but not so much.
The fuel pump is new, as the old one made unhappy noises. The new fuel pump fires right up when I do the fuse box jump. And when the car starts, the fuel pump noise is just beautiful.
When the care refuses to start, there is spark to the cylinders. This should verify the coil, distributor, ign amp, wires, and plugs (which are new).
When the care does start, the idle is a bit rough relative to other motors I've encountered, but it revs nicely, especially after I adjusted the timing to what the sticker in the engine bay says (which is different from the Haynes manual!). The roughness could be dirty fuel (old fuel can turn to something more like varnish over time).
Ok, everyone is thinking Hall effect sensor (me too). I understand that the ECU will not open injectors or command the fuel pump to operate unless it senses engine motion... BTW, the fuel pump does *not* operate when engine refuses to start, but as I said above, hot wiring the FP to operate is not the issue since engine still won't start.
Then there's the Tachometer. I've read that if the Tach doesn't "bounce" when the starter motor is engaged, its a bad Hall sensor. However, I've also noticed that when the car *does* start, the tach didn't bounce while the starter motor was doing the spin. Tach only comes to life when the motor is running. Then I've also read that the Hall to Tach signal follows a different (parallel) path then the Hall to ECU. At any rate, I do not know if this is significant.
Now this might be significant: The Check Engine Light illuminates for a very brief (less than 1 second) interval when I turn the key to "on". It stays off while the starter motor is engaged, and stays off whether or not the engine ignites.
So this is the point of this entire message. If the CEL flickers only briefly, does this point to a bad ECU? I plan to replace the Hall sensor anyway, simply because I fear that the replacement parts will not be available in the near future. And at 21 years old, its time anyway.
Meanwhile, it would be satisfying to solve the no-start issue, since this ship will stay docked until that time.
BTW, all the vacuum lines are fine.
Ground wires, and other connections suspect with intermittent starts.
thanks!
Ed
ps. the car is otherwise in great shape with only 125,000 miles on it, no rust. Radio doesn't sound so good, that'll be another post once we're cruising.
posted by 98.204.9...
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