Cilynder 5 missfire - 2003 Pontiac Montana

random misfires are from injector and low fuel pressure problems

Ok for code p1300 replace ignition coil 1 and 4 cilynder and for p1310 replace ignition coil 2 and 3 cilynder

If you had code 301 missfire for cylinder #1 and you changed #1 to #2 and the error codes moved to #2 then take about 3 seconds and say what did I do last. Then Change the #2 injector if it is still in the #2 hole.

3.9L V6 engine firing order is 1-6-5-4-3-2, cylinders on the pass side front to back are 2-4-6, cylinders on the driver side front to back are 1-3-5.

Have you confirmed there is no oil pressure and the oil level is full on the dipstick?

The oil pump is turned by the oil pump drive located under the throttle body. The oil pump drive is run of from the cam shaft. It is not uncommon for the camshafts to break on these engines.

It may not be a bad idea to pull the front valve cover and turn the engine over by hand to see if all the rockers are moving.

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sounds like u need 2 go over the whole ingnition system. unless u can isolate missfire down to one cilynder u may need 2 change rotor arm dizzy cap leads & plugs but maybe first start with a compression test 2 make sure rings&valves are ok and its not a low compression miss.sometimes it can be cheaper 2 have mechanic put car on a tune scope good luck

The number one cylinder is on the backside of the engine. You'll can check for spark and the condition of the spark plug. If there is no spark check the coil and the plug wire. If the plug is worn out replace it. If everything looks fine than an injector balance will need to be done to see if the injector is working.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

you may try your rotor button and distributor cap. and spark plug wires. try your map sensor also they tend to cause a lot of misfiring if they go bad.hope this helps.

ford starts with #1 is pass front #2 is 2nd pass from front #3 is 3rd pass front # 4 is forth from pass front now i dont know if it is a v8 or v10 if it is a V8 THEN # 5 IS THE FRONT DRIVERS SIDE IF IT IS A V10 THEN #5 IS THE REAR PASSENGER SIDE

timming belt failed