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Celica of Peril

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So sayeth the rules that us newbies have to post our first message herein. And so be it.

I've had the convertible itch since parting ways with my '71 Super Beetle, so I recently picked up an '87 Celica GT Convertible for cheap, to use as my fair-weather car. "Whore Red" as one co-worker described it. (that would be red, very badly faded, with just a touch of surface rust)

ST-162 & 3S-FE. Manual tranny. This will seem more important about five sentences from now.

It's not in horrible shape, in fact it's only got 90,000 miles on it. But the car has just never been maintained.

It's mostly been simple things- replace the shocks, fix the exhaust leak, replace the radiator, find the oil leaks, etc. But there's one that's really got me perplexed:

The car knocks pretty noticeably under normal driving conditions.

The timing is dead-on 10 BTDC at idle with the diag jumper in. I've replaced the coil, rotor, cap, wires and plugs (they all needed to be replaced), fixed the throttle position switch (it wasn't giving a closure at throttle closed) and installed a rebuilt air-flow meter. I also pulled the timing cover and valve cover to ensure that the cams were correctly aligned.


If I retard the timing to about five degrees it's drivable, though with a noticeable reduction in power.

Three things strike me as odd-

1) If I rev the engine while watching the ignition timing, it seems to go to full advance rather quickly.

2) When I measure the resistance across the AFM, it's not at all linear- it jumps up and down between 100-400 ohms several times as I open the flap.

3) Since there's no MAP sensor and no true throttle position sensor, I can't figure out what (other than RPM) is governing the timing!

So it's going to be an interesting project, I can tell already. But, it is a damn fun car. :)
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:confused: . sorry man, cant guess, as I was reading I was thinking in my head, MAP sensor, but then I read on and u dont have one :( . Good luck, try hitting up the tech section for help on that....someone's bound to think of something

Maybe God himself is governing the timing?
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