what position is the ignition rotor underneath the distributor cap in a 97 c1500 5.7L?
You really need a scan tool to set timing properly. Try crank the motor to TDC on the compression stroke on cylinder 1, pull the distributo rcap off and line up the rotor with the number 8 in the distributor base - you'll need a good light.
What do you mean what position should it be in? If you mean how do i get it in time its this simple. Bring your number one cylinder to top dead center. You can tell its top dead by taking out the spark plug and feeling the piston with a screw driver. After this, drop the distributor into place with the rotor pointing towards number 1 cylinder. On a vortec 350 the computer allows you a "window" you have to be in to have the engine in time, this is allowed because the spark is comptuer controlled, therefore no timing light is needed. It will automatically adjust to perfect time. So basically if you get it to top dead and pointed to number one, you should be fine.
wow wow wow what are U talkin about, oh yeah and Mike theres a 50 50 chance U will get it 180 off with your method(the screw driver ...bumping the starter over until U hear compression exscaping the spark plug hole guarantees U are on #1 compression stroke.
if you put #1 at tdc on compression and line it up to #8 the timing would be retarded as hell and you would have precombustion this is straight out of chiltons online 1. Start the engine and allow it to reach operating temperature. Stop the engine and connect the timing light to the No. 1 (left front) spark plug wire, at the plug or at the distributor cap. Do not pierce the plug wire insulation with HEI; it will cause a miss. The best method is an inductive pickup timing light. 2. Clean off the timing marks and mark the pulley or damper notch and timing scale with white chalk. 3. Disconnect and plug the vacuum line at the distributor on models with a carburetor. This is done to prevent any distributor vacuum advance. On fuel injected models, disengage the timing connector which comes out of the harness conduit next to the distributor, this will put the system in the bypass mode. Check the under hood emission sticker for any other hoses or wires which may need to be disconnected. 4. Start the engine and adjust the idle speed to that specified on the Underhood Emissions label. With automatic transmission, set the specified idle speed in Park. It will be too high, since it is normally (in most cases) adjusted in Drive. You can disconnect the idle solenoid, if any, to get the speed down. Otherwise, adjust the idle speed screw. The tachometer connects to the TACH terminal on the distributor and to a ground on models with a carburetor. On models with fuel injection, the tachometer connects to the TACH terminal on the ignition coil. Some tachometers must connect to the TACH terminal and to the positive battery terminal. Some tachometers won't work with HEI. WARNING Never ground the HEI TACH terminal; serious system damage will result. 5. Aim the timing light at the pointer marks. Be careful not to touch the fan, because it may appear to be standing still. If the pulley or damper notch isn't aligned with the proper timing mark (see the Underhood Emissions label), the timing will have to be adjusted. TDC or Top Dead Center corresponds to 0°B, or BTDC, or Before Top Dead Center may be shown as BEFORE. A, or ATDC, or After Top Dead Center may be shown as AFTER. 6. Loosen the distributor base clamp locknut. You can buy trick wrenches which make this task a lot easier. 7. Turn the distributor slowly to adjust the timing, holding it by the body and not the cap. Turn the distributor in the direction of rotor rotation to retard, and against the direction of rotation to advance. 8. Tighten the locknut. Check the timing again, in case the distributor moved slightly as you tightened it. 9. Reinstall the distributor vacuum line or the timing connector. Correct the idle speed. 10. Stop the engine and disconnect the timing light.
and no a scan tool does NOT help with timing on a car with a distributor
my 5.7 is missing all sorts of stuff to do the timing. i need to find a '97 5.7 vacuum advance distributor, i also need the crankshaft pointer and scaled harmonic balancer, is there any chance i can take those off my '83 350, no wait that doesn't have vac adv either. maybe there is some sort of plug and play device that would read the ecm and show differences in the crank and cam sensor positions...any help? i'm hoping to get it within 2 degrees of dead on.
im working on a 5.7 chevy now if i time the engine with the number 1 cylinder up on compression and timing mark on pully lined up for top dead center and the rotor is on number one it will not start but if i turn the dist to where it is on number 8 then it will start but runs ruff and misfires can any one give me some advise
Actually a timing gun is near useless for this vintage. The best you can do is top dead center line up all the marks on the distributor and reinstall it. The computer should be able to time it fairly closely untill you can have a shop time it with a scanner. I know you old fogies think this is stupid and im with you, but as i found out you cannot time it with a timing gun because the computer will fight you with any adjustments. I mean besides the fact that theres LITERALLY NOTHING to point the timing gun at
1990 k1500 5.7l TBI here: Run engine to OP.Temp. Disconnect TSL (timing service line) brown w/ black stripe (mine is located at firewall, some models [same year] are under glovebox insert at ECM). (If timing is off to start with:) Timing light, adjust dist. to 0°. Engine off, disconnect battery. Grab a helper, pull #1 plug, place finger over plug hole, manually rotate crank until you feel pressure (not suction). Check piston position with screwdriver (gently - don't want to mar piston), you want piston at apex of that stroke. This is tdc. You're timing mark should show aligned. Follow manufacturer instructions to install/replace distributor. Reconnect battery Reconnect TSL Start motor. *note: if you're like me, you like a little extra "oomph" on the throttle - I advance mine up to 20° when setting timing. The ECU reads whatever position you set it as 0° and adjusts based on load and/ or kncok & emmissions reading (GM shop bulletin - sorry, no reference to give atm, but I have read it myself). To advance set timing, reconnect battery (do NOT reconnect TSL). Start motor, advance by light/ear, shut off, disco' battery for 2 minutes (or bump ignition to discharge system). Reconnect battery, reconnect TSL, start motor and allow to idle ~2 mins.
Just so it is straight here, John has no idea what he is talking about. Read all the cheap manuals you want, just better make sure they are for the right year. All Vortec motors need a scan tool or something like EFI Live to access CMP Retard Offset PID. You will forever have a P1345 code otherwise and a vehicle that doesn't run like it should. From his copied instructions it is clear he has no idea what he is quoting. There is no "timing connector" or "vacuum" lines. It is possible to get lucky with these, but less than likely. Any decent shop with an old "brick" scanner should be able to get you setup for no more than 1 hour of shop time, or even free as it is pretty simple if you didn't get one tooth off dropping the dizzy in the first place.
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