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92 SC300 lives again....mostly. Help with idle/timing.

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Old 09-21-07, 10:46 PM
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slappy96
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Default 92 SC300 lives again....mostly. Help with idle/timing.

Car is stock-

Just got my engine back together from changing spark plugs, cleaning the throttle body and intake manifold. First shot it would turn over and wouldn't start. So I went back and removed the distributor, set TDC via-cam marks and crank 0 TDC mark. Then aligned the grooves on the distributor and shazaaam...it started first try. I haven't done this a whole lot so that was exciting, but a couple of things have caught my attention. 1. I can faintly hear some slight misfiring-especially if I go behind the car to the exhaust. Just some out of sync puffs. 2. A very slight amount of smoke from the rear of the engine. I obviously haven't fine tuned anything with a timing light. So, could I have gotten the distributor gear just one or two teeth off and cause this/these? I tried rotating the distributor at idle and that seemed to just speed up or slow down the engine. Didn't feel like it smoothed it out really.

Any help greatly appreciated. I'm about to move from California to Mississippi and I need this thing to run solid. For 1800 miles at least. Boost logic kit is on layaway until I'm not an idiot with the basics.

Slappy
Old 09-22-07, 10:37 AM
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DZLEXIK
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i have the same exact problem, after i did the tune up it started doing the same as you are describing...would like to know what is the problem too lol
Old 09-22-07, 09:36 PM
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slappy96
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Default Fixed

Well, I fixed it. I actually reset the engine TDC and pulled the distributor out again. I made sure the grooves were aligned and pointing at 1'oclock (toward the #1 ignition insert point on the distributor. Seemed to run a little better, but not perfect. Used a really crappy timing light to get it close. Car sounds amazing at higher throttle, but still idles a little rough. Useable for a cross-country. The light smoke may have been from some of the cleaner and dust used on all the parts. Seems to be gone. Not the most technical of solutions, but maybe some help.
Old 09-23-07, 09:23 AM
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JspecSC3
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Good to hear you got it fixed. Why did you have to play with the distributer if you were just changing out the spark plugs? It wasnt necessary.
Old 09-23-07, 11:25 AM
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DZLEXIK
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I did a tune up and replaced plugs,wires,cap,rotor,fuel filter,airfilter,cleaned throttle body and now it acts up...its gotten better since it started, but the misfire is still faintly there. You can feel it at idle, shaking the car and hear it at the tailpipe..

Also when i let go of the gas, it feels like it backfires also, sometimes it does it so bad, that it jerks the car..(as if im letting go of the clutch too soon) And it loses power...Anybody know whats up?
Old 09-23-07, 04:35 PM
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JspecSC3
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Originally Posted by DZLEXIK
I did a tune up and replaced plugs,wires,cap,rotor,fuel filter,airfilter,cleaned throttle body and now it acts up...its gotten better since it started, but the misfire is still faintly there. You can feel it at idle, shaking the car and hear it at the tailpipe..

Also when i let go of the gas, it feels like it backfires also, sometimes it does it so bad, that it jerks the car..(as if im letting go of the clutch too soon) And it loses power...Anybody know whats up?
Did your spark plugs come pre-gapped to .44? Sounds like an issue I had two years ago with my SC. If you are still getting misfire you should double check your timing with a timing gun. I would also check the distributer to see if you need to retard or advance the timing from there.
Old 09-23-07, 10:06 PM
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slappy96
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Default Jspec..What did you mean?

JspecSC3,
What did you mean check the timing at the distributor and go from there? Just wondering if you are talking about something besides using a timing gun on the crank and rotating the distributor based on that. I haven't done this a whole lot, so I'm always afraid I'm missing something that everyone already knows.

Also,
DZlexic-I almost goofed with the timing gun. Don't know if you used one with an advance dial, but the Sears one I used moves real easy. I was doing the timing and looked up at the dial and it was up at 15deg advance. I would double check that it's 10deg prior to TDC with 0 advance set on the gun. I suppose you can use the 0 mark on the crank and set the gun to 10 deg also. At any rate, I think both of you guys for the help and interest. More to come on my beast, but I'm moving across the country in 6 days and I just had to get it driveable for the short term.


Slappy
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