About 3-4 weeks ago, I started changing my plugs out on my 1997 f150 4.6 V8 without COP. During the process, i noticed that i had alot of built up dirt around the plug wires (I know because some got knocked down in on top of the plug!)...So I washed it at the car wash.. I know, bad idea....

Well, it barely made it home it was running so rough. I let everything dry out for about 2 weeks and just borrowed a different car. I changed the plugs out to Bosch plus 2's... I know.. second mistake right?.....and now, 3-4 weeks into this, all the plug wells are really dry.

The truck still acts like it's not getting any fuel/air and severely lacks powers. It seems to idle fine. I've checked to make sure my battery is good and alternator is still giving out enough power. Don't know what else to check! Help!

 

It is more than likely your wires. There was no mention of you changing them...

Be sure to use plenty of dielectric grease when installing wires.

I will HIGHLY advise, you need to get MC plugs in there.

Myself, and many others have not had any good experience with a bosch plug.

How many miles are on the coil packs?

 

I haven't changed the wires. I already planned on switching back to MC plugs after reading several posts on the forum. My engine does not have COP's. They would be right on top of the plug boot if I had them right?

 

Yes, they sure would be on top of the plug if you did have COP's.

I SAID "COIL PACKS". You have 2 coil packs, on your engine. One on the left and one on the right. It is where the other end of the wires connect to get spark...

Sounds like your wires are bad. Over time they get cracked and will arc, diverting the full amount of power away from the plugs.

Make sure you use plenty of dielectric grease when installing wires and plugs, or you will end up wit the same troubles.

 

Gotcha. I bought the truck two years ago and have put maybe 20,000 miles on it.. I don't know if the previous owner had done the coil packs so there is potential for many miles on them. How many miles are they good for? Is there a way to test the coil packs to see if they are still good?
Also, would washing the engine be the cause of my wires failing all of a sudden? The truck ran great before the washing.

 

Washing your engine with a pressure washer can cause a MULTITUDE of crap to go bad.

How many miles are on the truck? Being as you changed the plugs, you admitted to yourself that this truck needed a tune up. With that said, WIRES ARE PART OF A TUNE UP.

I doubt that the COIL PACKS are bad, unless you absolutely drown the engine. Then, more than likely you have caused them to flip out. Go with the MOTORCRAFT plugs and WIRES and that should get her back on the road. Be sure (like stated before) to use plenty of dielectric grease.

 

Sounds like good advice. With all my vehicles before getting the f150 (with COPs), I ALWAYS washed the engine anytime I washed the car - hate dirty engines, and I think they're a fire hazard. Never had ANY problems unless I got water into the distributor and, you can guess what happened then. But, once it dried out, everything was fine again. Does the older f150 use anything like a distributor along with these coil packs?

- Jack

 

Distributor-based ignition systems use only a single coil. The output of the ignition coil is what is being "distributed".

Steve

 

My 1997 4.6l has always been very sensitive about plug wires. Replace yours ASAP, but use only Motorcraft wires; other aftermarket wires just don't work as well...PERIOD! If that doesn't cure the propblem, then replace the coil packs on each cylinder bank. I used Accel units, and they seem to work fine.

Jim

 

Thanks, I figured there was an electronic way to send the spark to each of the four cylinders rather than using a mechanical distributor, but I'm still getting used to the idea of having COPs and "drive by wire" instead of the older stuff.

Sometimes I wonder if this is really "progress". A 4WD I take through mud and dirt and I can't wash the engine?

- Jack

 

You can wash your engine. You just need to use common sense and not direct spray into electronic components. I wash my engine all the time. 121K miles later still no engine problems.

 

Well, CHICKADEE, What did you find out?

 

Well when washing your engine make sure the truck is running and if you get water into the intake housing it will take a bit longer to dry then water on the surface, same goes for your spark plug tubes.

 

The trick to using a PW to wash an engine, is to keep the tip about 2-3 feet away from whatever you are spraying.. At that distance, all you get is a MIST of water... That's enough to rinse off the engine gunk spray you applied a few minutes before.. If you use a hose with a spray nozzle, you are dumping gallons of water on an engine and that'll drown it in a minute...

Only sweep the mist spray on the intake it get it wet, then wipe it off later. You can get closer to stuff on the valve covers and the firewall, but stay away from connectors and other electrical stuff...

It's just common sense and not a "Saturday bath day" when washing down a modern engine..

I've washed my engine only 3 times, but never had any problems after doing it...

Mitch