Finding top dead center on 1997 Blazer with 3.0 and #1 on spider cap

Older 4.3 engines have a problem with the distributor gears. Put the engine on top dead center. pull the cap and mark where the rotor sets. Pull the distributor. Look at the gear. if it is worn/not a smooth touch, replace it.

ok so its out of mechanical time..bring the numer one cylinder to top dead center(line up timing marks) and take the distributor cap off.. see where the rotor is pointing..find #1 wire and locate it on the cap..if not right, redo wiring at the cap..in proper firing order..then if it does start..adjust to proper timing..most are 5-7%before tdc..as it is idleing

That could be correct, or 180 degrees off. Top dead center on the crank shaft can be on the intake or exhaust stroke.

if it is a 4.3 v-6 with multiport injection ,it may be the spider unit. try putting gas into the throttle body and see if it starts. if it does than replace the fuel injection unit (spider unit)

If you need further help, I’m available over the phone at https://www.6ya.com/expert/david_4c166ba81493f541

Here is a picture for you. Zero is Top Dead Center, but If I remember right you have to disconnect a wire in the cab under the glovebox when you set the timing.

ok this is hard to explain look to see on the cap ware no1 wire is put the engine on top dead center (0) when you put the distributor in look at the cap and ware the rotor is pointing get it as close as you can to no1// when you get it in have some one try to start the car while you turn the distributor to the left or right if it starts you need a timing light to set the deration/// if you get a lot of back fire you are probably out 180 deg then try again hope this helps good luck

check out helpwrench.com under the vortec section.

The ignition timing is not adjusted with a timing light or with the engine running, and to set the ignition timing follow these proceedures.

There is a mark or notch on the distributor housing that the rotor should be pointing to when the engine is on top dead center. This "static" timing is all that matters and the computer will be able to control the timing as long as the ignition rotor is in that position when the engine is at top dead center.

1. Place the engine at top dead center.

2. Look under the distributor cap and find where the number one terminal runs under the distributor cap, and where that position on the distributor cap corresponds with the distributor housing, and it should match up to a mark or a notch on the distributor housing indicating the number one position.

3. With the engine on top dead center the ignition rotor should be pointing to the number one mark or notch that is on the distributor housing, if it is not then loosen up the distributor and turn the distributor until the ignition rotor is pointing to the mark or notch on the distributor housing and then tighten down the distributor, the engine should now be static timed.

If the distributor can not be turned enough to align the ignition rotor with the number one mark on the distributor housing, or the distributor does not set properly and will not allow the installation of the spark plug wires then the distributor is not installed correctly and is most likely a tooth off and it will need to be re-installed correctly. (The distributor should set like it is shown in the firing order diagram when it is properly installed)

Here is a firing order diagram to also help assist you.

take #1 spark plug out turn the engine untill the piston comes up to to dead center TDC on the compression stroke Take the distrib out and put it back in pointing directly at #1 plug wire on the cap