What are the right sparks plugs for a flex fuel 5.3 engine

Check compression in number three. You could have bought a bad engine. And yes. You need to change every sensor. If they don't match with the plugs. replace the engine. There is a reason for different engine codes. You should have stuck with them.

Have you ever changed the spark plugs? ..changed the fuel filter?.. air filter??.. replace these and see if it gets better.. you can do this yourself..
get one of these..
2004 Ford Explorer Repair Manual Vehicle Maintenance

http://www.rockauto.com/en/catalog/ford,2004,explorer,4.6l+v8,1427802,literature,repair+manual,10335

best answer here is that the sensors are not set for the poor quality fuel ( the octane ratine is probably to low for the ECM to properly maintain the air /fuel mixture ) you have the answer to your problem when you change back to quality fuel and it runs right. As a point of interest most small engines will not run right on e fuel mixes.

It's something electrical or electronic . Check for spark after it stalls an before it cool's down ! Pull a plug wire an buy a spark tester an install the tester on a plug wire .Have someone try to start the vehicle . Could be a crankshaft position sensor . If there is spark buy a fuel pressure tester an test the fuel pressure . Have the vehicle hooked up to diagnostic scan tool ,check engine sensor data parameters .

Ford numbers the cylinders on the V6 as follows: The right hand bank [or bank of cylinders closest to the firewall] are numbered front to rear as 1, 2, & 3, The left hand bank of cylinders [closest to the radiator] are numbered front-to-rear as 4, 5, & 6.

the injectors are leaking ---injectors seals are leaking or if carby the needle and seat is not sealing off and controlling fuel flow to the float bowl
it is not a plug problem but excessive fuel into the manifold

For the 2002 Dodge Caravan (and Grand Caravan) ALL 3.3L V6 Engines (including the Flex Fuel): Also for 3.8L V6 Engines:

Firing Order:
1-2-3-4-5-6

Cylinders:
........(back).......
|...1....3....5...|
______________
|...2....4....6...|

Ignition Coil:
.......(back)
electrical connection
...........|
..........V
5........1........3
2........4........6
.......(front)

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!

It is a miss fire on number 5,it could be a bad spark plug,or boot on the coil to spark plug,do a spark plug change out .

Wiggle the key in the truck when the truck is running. Your losing fuel or spark. Check connections in the fuse panel. Check wiring harnesses for tight connections. Email me back. [email protected], Good Luck Jim

There are six VIN numbers of engines for the 1991 Buick Lesabre, with a 3.8 Liter engine.

1.Vin B
2.Vin 3
3.Vin C
4.Vin 1
5.Vin L
6.Vin K

All have the Firing Order of 1-6-5-4-3-2

For Vin B and 3:
Hood open, looking at the engine from the front of the car. The coil pack is behind the engine, close to the firewall. (Under the windshield)
The crankshaft pulley is down on the left side.

Spark plug numbering, for the spark plugs close to the radiator side.
From Left; (Front of engine), going Right-> 1-3-5
Spark plug numbering, for spark plugs on the backside of the engine.
From Left going Right-> 2-4-6

The distributorless coil pack sits on the backside of the engine, close to the firewall.
Numbering of where to put the spark plug wires;
There are three spark plug towers close to the engine. From Left to Right -> 3-5-7
There are three spark plug towers far from the engine. From Left to Right-> 6-4-2

For Vin C, 1, L and K:

Hood open, facing the car.
The Front of the engine faces to the Right. The crankshaft pulley is down, and to the Right.

Spark plugs close to the radiator;
From Left to Right-> 6-4-2
Spark plugs close to firewall, (Below windshield)
From Left to Right-> 5-3-1

The distributorless coil pack sits on the right side, in front of the engine. (The Front of the engine is on the right side. The crankshaft pulley is on the Right side)

Starting at the ->Back and coming Forward. (To the Front of the car)
On the Left side of the Distributorless Coil Pack, it is -> 4-2-6
On the Right side it is -> 1-5-3