4.3 L vortec firing orcer and wiring diagram

The firing order is printed around the top of the motor beside the valve cover. Did you put a new distributor, rotor cap, or button In it.

See diagram

if it is a vortec motor the wire numbers are on the cap 3 on one sid 4 on the other one of them being the coil wire

Check the plug wire from the ignition coil to the distributor cap.
If you haven't already, replace the distributor cap and rotor.
The GM Vortec's have issues with moisture getting inside the cap and rotor and causing problems.

1-6-5-4-3-2 The driver side is odd and the passenger is even. front of the motor is low number cylinder going up to the firewall

Hope this was of help to you.

991 Chevy S10 firing order
The firing order for a Chevy s10 depends on which engine you have.
1.9L engine the firing order is: 1-3-4-2 . Distributor rotates counterclockwise.
2.0L engine the firing order is: 1-3-4-2 . Distributor rotates clockwise.
2.5L engine the firing order is: 1-3-4-2 . Distributor rotates clockwise.
2.8L engine the firing order is: 1-2-3-4-5-6 . Distributor rotates clockwise.
4.3L engine the firing order is: 1-6-5-4-3-2 . Distributor rotates clockwise.

The color codes will be different so when you take the harness off the 95 make sure that you label ALL the connectors to make it easier to install it on your Blazer. You may also have to change some sensors or switches up to 95 so that the harness will fit. Label all the empty connectors with their location in the 95 because they will be for options that may or may not be on your Blazer. If you have to access a wire diagram to complete the job then use the 95. DON'T let someone else take the 95 harness out for you andtake a rough diagram of your truck with the plug-ins marked for location and # of pins for wires. Basically it should fit but attention to detail is a must.
Also check out faxonautoliterature. They list GM service manuals but also GM books for engine interchanges that may prove to be very helpful. Hope this helps.

Firing order is 1,8,4,3,6,5,7,2. cap should show cylinder numbers.

Same as a Chevy. Standing in front of the truck.. 2-4-6-8 on your Left. 1-3-5-7 on ur Right.. Firing order is 1-8-4-3-6-5-7-2 Thanks.. Have Fun