P0351 on my 1998 Explorer V8.

[RICHARDG323]

Hi guys im getting code p0351 and misfire on cylinder #1 and #6. I change the coil , plugs and checked the wires. The problem is there is no spark comming from the coil where it normaly would go on cylender #1 and #6 . Ichanged the coil and didnt work still no spark on the new coils ?? What should i do?

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the EEC-V section.

 

[2000StreetRod]

waste spark partners

P0351 Ignition Coil A Primary/Secondary Circuit Malfunction

Cylinders #1 and #6 are waste spark partners (fire at the same time). If you've replaced the coil pack on the left (driver) side with a new one and are still having the problem then I would suspect the wiring that runs from the PCM to the coil pack. The DB/LG wire is the one that provides the electrical path for coil #1 (cyls #1&#6) to fire. Inspect the connector for problems at the coil pack end. You might try disconnecting and reconnecting the main PCM connector and make sure the securing bolt is firmly (but not overly) tightened.

 

[RICHARDG323]

Where is the pcm located on a 1998 eplorer v8 5.0 model

 

[2000StreetRod]

PCM location

On the firewall, passenger side there should be a large electrical connector with a bolt that keeps it in place. The PCM is behind the electrical connector. There is no need to remove the PCM. Just disconnect and reconnect the electrical connector using the bolt.

 

[RICHARDG323]

I disconected and connected the pcm and that didnt work. What do you recomend i do next???? Im still getting p0351 and no spark from the coil for cyclender #01 and #6. ??

 

[2000StreetRod]

Swap coils

How did you determine that there is no spark on cylinders 1 and 6?

I know you stated that you replaced the coil pack but I would like to double check. The coil pack on the driver side is for cylinders 3/5 and 6/1 with 3/5 aft and 6/1 forward. The coil pack on the passenger side is for cylinders 4/7 and 8/2 with 4/7 aft and 8/2 forward. The engine cylinders on the passenger side are 1 thru 4 with 4 at the front. The engine cylinders on the driver side are 5 thru 8 with 5 at the front. I suggest that you label all of the plug wires at the coil packs and then swap the left coil pack with the right coil pack and vise versa. If the misfire moves from 6/1 to 8/2 then you know that coil pack is bad. If the misfire stays with 6/1 then it's not the coil pack.

 

[RICHARDG323]

I tried changing the wires all around to determin its not the wires and they are in proper order and also changed the spark plugs. I determine the coil is not giving spark by disconecting the wires while car is running and no spark coming from #01 and #06 the rest ot he coils have spark coming threw them. I replaced the coil and it was the same suitiation no spark from #1 and #6 . I disconected and reconected the pcm and no luck . A friend of mine told me to check the crank senser?

 

[2000StreetRod]

Crankshaft position sensor

Either the wire from the PCM to the coil pack for cylinders 1& 6 is broken or shorted or the PCM is not internally grounding the wire to fire the coil. I agree with your friend that the crankshaft position sensor could be faulty. Try disconnecting and reconnecting the electrical connector to the sensor a few times to clean the contacts. Some members have had luck with tapping the sensor. My Haynes Repair manual describes a couple of simple tests for the sensor using a multimeter. If you don't have the repair manual but have a multimeter I can post the text describing the tests.

 

[WorkInProcess]

Hey guys. I was getting P0351 ignition coil a and a cylinder 1 & 6 misfire. I read that if I swapped the coils, then 2&8 would misfire telling me that coil was bad.

So I swapped the coils, and now I am getting P0352 ignition coil b. Can I conclude that it is the coil causing this error and buy a new one? I don't want to keep purchasing unneeded parts so want to narrow this down 99% sure.

The plugs where replaced less than a year ago, so I doubt that is the problem. One of the wires was showing age, but it didn't give me any problems after I changed the plugs.

99 5.0 Explorer

 

[TestPoint]

Explorer wasted spark coil wiring

I searched for a week for this information a year ago. It is not in the big factory service books and a local Ford tech could not find any documentation on it. Here is a picture of the coil to cylinder connections:

 

[WorkInProcess]

I just drove it a bit longer, and after switching the coil packs to left and right, it gave me a misfire in cylinder 3&5. Maybe just a new set of wires?

 

[TestPoint]

If you will note in the above picture swapping coils rotates them 180 degrees. If the original issue was a defective coil on 1-6 (front left) and you swapped coils the problem should move to 4-7 (rear right).

Your 3-5 problem doesn't confirm a bad coil pack nor wires but might suggest a connector problem.

If your wires are original I am sure that the truck would appreciate a new set.