97 gmc 5.7 marks on inside of distributor to set timing

Doesnt really matter it will work either way around ,.now the plus is the feed from the loom and negative goes to the distributor.good job some of us old time mechanics are still alive ..

With ignition OFF, remove the dist cap , do not remove HT leads from cap or plugs just move to one side ,turn the crankshaft with a spanner on the crank pulley drive nut until the rotor arm is pointing directly towards the front of the vehicle, mark the position of the rotor on the distributor body with a dab of paint and also mark the position of the body on the engine block infront of the distrbutor,remove the distributor , i believe it's just 2 screws that clamp it in place ,transfer the mark from old dist to the new dist and aling the rotor to this mark, then fit the new dist to engine and aligne the marks from the new dist to the mark on the engine block and tighten down , refit the dist cap , to get an exact distributor timing you should now use a timing light to check the timing marks line up , if they are slightly out just very slowly turn the distributer until the marks are aligned , hope this is of help

Sounds like you replaced the distributor without setting #1 at TDC? The distributor cap should indicate which plug is the #1 plug wire. If there are no inspection plugs you can pop out to see the timing marks on the camshaft gears you will need to disable the starting system (fuel flow) remove #1 plug and turn it over until #1 piston is at TDC on the compression stroke. Then insert the distributor cap with the rotor on it, taking note of where the #1 plug tower is on the cap. Once the dist is installed place the cap on and make sure the end of the rotor is aligned with the #1 tower inside, if it is your good to go. If not take the dist out and turn it a bit left or right then put it in again until it lines up correctly (may take a few tries). Once aligned secure everything, replace spark plug and it should fire up.

Remove the dist cap, mark the direction the rotor is pointed as close as possible for reference on the new one. Next mark the location of the distributor shaft to the surface of the intake for reference. Remove the bolt and disconnect the wiring, twist the old dist back and forth and pull up, it may be stuck so just work it back and forth. Install new dist using alignment marks made earlier, leave hold down bolt slightly loose and set timing to 10 BDTC with the spout timing shorting bar removed (near ignition control module).

Best practice is to remove #1 spark plug, roll engine over by hand until #1 piston at top dead center on compression stroke. Remove dist cap , find a surface outside of dist to mark direction rotor is pointing then mark dist body position. Remove dist ,you will notice as you lift dist, rotor will spin backward keep an eye on it, when the rotor stops spinning as you lift, that will be your dropin position for new distributor. That will get you close,enough to start car but you will need a timing light to set exact timing

gyver here , twenty year wrencher.. sounds like either you got the timing out on the distributor , or the timing on the crank and cam are off. if you know the timing marks were set cam at twelve crank at six the dist is out. common for guys to set cam and crank n marks one above the other but then you must rotate engine 360 degree before you set dist back into hole. pull dist up rotate 180 degree .let me know

The distributor is only for injector timing.
Do not move it.

94-97 Back Probe 5 Vref Wire at dist.
Tan/Yel Wire

Move dist till you switch from 5 volts to O volt,then lock down

Only do this if you moved dist,during chain replacement or assuming the dist
set timing ,which it does not.

The camshaft sensor is located inside the distributor and is part of it, in order to replace it you must replace the distributor,to replace remove the dist cap. mark the location of the rotor,by marking where its pointing to, then mark the dist housing, so now theres a mark on the rotor and housing to show where rotor points, next mark the location of dist going into housing, mark the shaft and the block,because it spins in block this way you can line back up.next remove hold down bolt and pull out,mark the new dist in exacat same spots as the old so you can install back the same,you may have to put it in and pull it out until your marks are lined up,this way the timing will be dead on, when done you can check timing. good luck

Roll the engine around until the compression stroke on number one cylinder (both valves are closed) and stop on top dead centre. The rotor should be pointing to the number one terminal on the distributor. If it is not extract the distributor and replace it with the rotor pointing to number one. That should be it. Hopefully their are no other issues relating to the original breakage so you should make sure the new distributor is spinning normally.

You will need a timing light for Hi energy ignition as well as standard socket set or wrenches. 1. get the engine up to operating temp. 2 shut off engine connect the timing light to the number one[1] spark plug wire at the spark plug end connect battery connectors. 3 start engine and note location of pointer on the mark tab on the timing cover. 4 shut off engine loosen the hold down clamp on the distributor turn the bolt no more than one full turn[snug is better than loose here] then note the position of the dist. cap. Move the dist. to make sure it moves freely replace back to the starting position and remove and plug the vaccum line to the dist. 5 start engine and set timing to the desired spec. 6 shut off engine tighten dist. clamp bolt 7 start engine check timing one more time to see if still there at desired setting. 8 shut off engine dis-connect all tools and light