Help: Car sounds like helicopter

I recently replaced the ignition wires in my F355 M5.2. I checked all the spark plugs when I made the change and they looked fine. About a month later, the new #1 wire melted against the block for some reason and shorted. I found this because the car started missing out. I ordered some new 7mm copper core cable from Kingsborne and rebuilt the cable.

Now when I drive the car it runs fine about 10% of the time and the remaining 90% of the time it is missing out and sounds like a helicopter. I pulled the #1 plug from the distributor and the spark is very strong. It also jumps from the distributor to the plug indicating that there is a connection on the spark plug end. When I pulled the plug from the distributor, the engine noise didn't change much. I tried pulling a spark plug boot out, but I can't seem to get them loose. I'm going to try to fashion a tool to help.

In the mean time, if I don't see anything wrong with the plugs, any ideas of what else to look at?

Thanks,

Tom

 

These are the ones sold by Ricambi. I hope that doesn't end up being the issue. What do you recommend for wire? I can rebuild them by reusing the boots.
I'm planning on having my major done this spring, so I'll be seeing you then.

 

Take a look at them at night, look for sparking

I run with the cover off, runs much better

 

I did that last night. No sparks or blue lights at night. The last set did that.

 

100% positive you didn't get your wires chris crossed?

 

I just checked. They are correct

 

Do you still have your old wires? I'd start swapping wires until you find the trouble maker.

 

That's a good idea. I just need to figure out how to pull the plug boots out without pulling the wire.

 

The wires need to be the wound core. Solid core wires won't work properly.

 

I would change, at the very least, the plug with the shorted wire and probably all the plugs because I have been bitten by the "it has new/good plugs" excuse on more than one occasion.

 

Bruce I didn't know that what happens if you use solid by accident.

 

I can't give a scientific explanation, just my experience. On a 328. Put on solid core wires. I was thinking I was putting on better wires. Car wouldn't run right, drove me nuts. Miss, miss, miss. Friend said ya have to use wound core. I did. Car ran perfectly. I dunno, maybe the solid core wires did such a good job, they drained the coils and they didn't recharge fast enough for the next spark. Like I say, I'm in no way an expert on electricals. Don't know a watt from an ohm.

 

Ok so solid core gave lots of misses then. Our 355s and 348s both use wound cores then. Is this correct?

 

You can make your own tool to pull the wires.

 

I believe the original wires were copper core. I did however notice that after I installed the new wires, there was a significant amount of whining noise in the stereo. The new wires are also copper core. I just ordered some bulk Kingborne 7mm mag-wire wound wire. We'll see if that helps with the whining. I will also try replacing the spark plugs. NGK PMR8A correct? Or is it PMR7A?

 

Pmr7 (hotter) for 2.7 cars pmr8 for 5.2.

 

Those non resister wires really crossfire, use them for magneto blower motors running alcohol or nitro not these wind up toys

 

So I bought some Kingsborne 7mm Mag-Wire Wound Wire and installed it into my #1 ignition wire. The copper core cable measures 6.2KOhms, but the wire wound cable measures 7.5KOhms. Is this alright for the F355 M5.2 or should the resistance be lower? I want to be sure before I modify all of the wires.

I am also installing new PMR8A plugs all around.

 

I went ahead and updated all 8 wires since it is fairly simple to change them back if needed. I had a problem with one of the boots arcing, but I pulled it apart and reassembled it which seemed to resolve the issue.

Overall, it definitely runs better. I didn't get a chance to drive it down the road yet though. Hopefully I'll have time to try it on Monday afternoon.

 

Cool
Weird that the solid core wires are "too good", huh?

 

The solid core wires worked for a couple months, then quit. I also changed the plugs, so it is possible that the plugs were the issue.