5.7L Timing at 46 Deg. ATDC?! Can't Find DST Wire.
09-14-2006, 10:53 PM
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5.7L Timing at 46 Deg. ATDC?! Can't Find DST Wire.
Inherited project car, now my project.
1984 Camaro Z28 H.O.
Work previously done on the car 1996, then the car sat for 10 years 1984 Camaro Z28 H.O.
Swapped out 5.0L H.O. to 5.7L H.O. L98
New Roller Cams, bigger fuel injectors in 4BRL Carb. "Rochester".
Higher Gear Ratio 5-Speed Trans. upgraded.
High Flow Exhaust.
Engine Balanced on rebuild as well as bored out bigger.
After all that engine is suppose to output close to 400HP.
(Can chirp tires in first 2 gears) Fun Car!
2006
All fluids replaced, all tune-up stuff.
Harmonic Balancer replaced.
Rochester 4BRL Carb. had a complete rebuild.
Runs pretty well now,
PROBLEM
But CAN NOT TIME ENINGE IN ORDER TO PASS CA. SMOG
Timing light shows +46 Degrees. I looked for "DST Wire" to disconnect it, but can't find it. Also I think I am supposed to disconect a Vaccum hose too. Little HELP!
Thanks,
DanManZ28
09-15-2006, 06:14 AM
#3
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On an 84 the original cvomputer controlled distributor didn't use a single timign wire like later TPI/TBI engines. The "timign wire" is actually a 4-wire connector that comes out the back of the distributor and connects with a matchign connector coming out of the wiring harness behind the engine, above the tranny bellhousing.
But you say you have it converted to carb (actually you say bigger injectors in a 4bbl Rochester- which is confusing. Is it fuel injected or carbureted?).... is this an earlier non-computer-controlled carb and distributor? If so, your computer isn't controlling the timing any more- you just remove and plug the vacuum advance line at the distributor (the little vacuum can sticking out the side), set the engine to a low idle and set your base timing, clipping the pickup on the #1 plug wire (driver's side, front most).
If you're still getting "insane" results, post back- with the mods it's possible you have a mismatch between your timing tab and the mark on the balancer (GM used 2 different positions for them and mismatches are common when doing non-stock combos, engine upgrades, etc).
But you say you have it converted to carb (actually you say bigger injectors in a 4bbl Rochester- which is confusing. Is it fuel injected or carbureted?).... is this an earlier non-computer-controlled carb and distributor? If so, your computer isn't controlling the timing any more- you just remove and plug the vacuum advance line at the distributor (the little vacuum can sticking out the side), set the engine to a low idle and set your base timing, clipping the pickup on the #1 plug wire (driver's side, front most).
If you're still getting "insane" results, post back- with the mods it's possible you have a mismatch between your timing tab and the mark on the balancer (GM used 2 different positions for them and mismatches are common when doing non-stock combos, engine upgrades, etc).
Last edited by Damon; 09-15-2006 at 06:17 AM.
09-15-2006, 06:23 AM
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Sounds like this is a car originally with a carb (L69) that's had the ZZ3 or ZZ4 conversion done to it.
The computer-controlled carb gets its timing set by unplugging a large Weatherpack type connector that is attached directly to the distributor. If you examine the base of the dist, you'll find 2 harnesses coming out of it; one plugs into the cap, and the other is about 10" long and plugs into a harness going to somewhere else. That second one is the one. Unplug it, start the car (the check enging light will be on), and set the timing.Should be 6° BTDC IIRC.
However, it also sounds like you've got the wrong timing mark thing going on.... the original timing mark is almost dead center on the timing cover, you look down behind the water pump to see it; the crank damper has the line on it inscribed accordingly; some other motors have their fixed timing tab in other places, such as under 2 bolts at the edge of the timing cover (about 35° different); if you have a damper with the line in the wrong place (either because it's mismatched to your cover, or because the outer ring has slipped), the mark will read wrong.
Your carb has no fuel injectors;
whatever was done to it, it wasn't larger those.
The computer-controlled carb gets its timing set by unplugging a large Weatherpack type connector that is attached directly to the distributor. If you examine the base of the dist, you'll find 2 harnesses coming out of it; one plugs into the cap, and the other is about 10" long and plugs into a harness going to somewhere else. That second one is the one. Unplug it, start the car (the check enging light will be on), and set the timing.Should be 6° BTDC IIRC.
However, it also sounds like you've got the wrong timing mark thing going on.... the original timing mark is almost dead center on the timing cover, you look down behind the water pump to see it; the crank damper has the line on it inscribed accordingly; some other motors have their fixed timing tab in other places, such as under 2 bolts at the edge of the timing cover (about 35° different); if you have a damper with the line in the wrong place (either because it's mismatched to your cover, or because the outer ring has slipped), the mark will read wrong.
Your carb has no fuel injectors;
whatever was done to it, it wasn't larger those. 
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