I need the firing order of 1996 gmc engine sierra 5.7liter vortec

Here's a diagram
http://ricksfreeautorepairadvice.com/5-3-v-6-firing-order-vin-g-p-t-z

1-6-5-4-3-2

the cpu has found sensor/s that are outside set parameters. have the fault codes read and replace found faulty sensors.

starting from the front working clockwise its 1 6 5 4 3 2 . number 1 cylinder is front right

Heres a diagram with the firing order for your 1997 sierria with a 6 cylinder engine, hope this helps,

1--6--5--4--3--2

Replace the coolant sensor on the front of the intake manifold.The coolant sensors on this engine does go bad and wont set a check engine light. The sensor will read about -32 to 0 degrees when they do go bad. The computer thinks it is that cold and sends tons of fuel to the engine. If you try to start the engine with the throttle depressed to the floor it puts the fuel system in clear flood mode and wont fire the injectors. Engine will start then and run very rich. The coolant sensor has two wires on it and sometimes you need to replace the wiring pigtail going to it as the sensor can seep coolant into the connector and corrode the terminals. All the parts are available at pepboys and autozone or napa. Good luck

1-6-4-5-3-2

clockwise rotation

front - 2-4-6

rear 1-3-5

good luck!

hi all the exturnel parts are the same a 350 will go right in .the valve covers,intake oil pan all the same

couple of things, did you actually gap the plugs yourselfor did you go on the assumption that they are pre gapped ? are the lead wires all in the correct firing order ? Is it possible a vacuum line got dis-connected ? I would also check the cap and the rotor.