HELLPPPP! I've sat here reading all these posts about misfires and I think I have ended up more confused! My truck starting missing a few weeks ago, at first only when going up a hill... not just driving around in the city. The Check Engine Light came on, stayed on, and starts flashing when it is missing, stops flashing but stays on when it's not.

I took it to the mechanic, they replaced the spark plugs. Now it's missing just sitting at a red light. Took it back again and they said they cleaned out the throttle body. They guy kept it over night to drive it 40 miles home to make sure it was okay. I pick it up and could tell right away that it still wasn't right. It just didn't feel like it had it's power back. I drove it to the lake, some 115 miles away, didn't miss any but it just didn't feel like it had it's power. Sat in the rain all night, start it up the next morning and it was missing worse than ever. I've called the mechanic to take it in for the third time in the a.m... any suggestions on what I should say to them??

Thank you for any input!!
Daina

 

When you say you took it to the mechanic was that a Ford dealer? I had a similar problem with my truck about 6 months ago and I had to replace a COP (coil over plug) on one of my cylinders. The mechanic I'm sure read the code from your truck and it would of told him which cylinder had the misfire. If the new sparkplugs didn't do the trick I would try a new COP on that cylinder. That's something you can buy and put on yourself. I wouldn't shell out more money for another diagnosis and labor just yet.

-Brian

 

Hey Brian! Thanks for replying! It was not a Ford dealer. I went to a friend of mine's mechanic that he really likes and trusts.

 

My 98 4.6L V8 had similar problems.

Check out my reply to this thread: https://www.f150online.com/forums/sh...hreadid=107049

Also, click here https://www.f150online.com/forums/sh...threadid=85603

Here is what it took to get it running right:

1. Check all fuses and o2 sensor (NC labor)
2. Replace plugs (8 @ $4, 1 hour labor)
3. Replace plug wires (Beldin lifetime warranty $112.98, 1.3 hours labor)
4. Replace TPS and CTS (high voltage) (TPS $59.95, CTS $28.10) (1 hour labor)
5. Scanner & trouble shoot (NC labor)
6. Compression check (0.4 hour labor)
7. Clean injectors ($12 machine, .4 labor)
8. Tighten and clean all injector harnesses (NC labor)
9. Check EGR valve, throttle body, gaskets and vacuum system (NC labor)

Total for parts, labor and tax = $520.64

 

I don't think the 4.6 has coils on the plugs.. has two coil packs on each side of engine.

Check your plug wire.. My #3 plug wire had a small hole in it and was shorting out on the cylinder head causing the engine to MISSTERIOUSLY miss.. then I replaced the plug wire and my misfire was gone.

 

I'm pretty sure his 98 has them... I can only speak of the 4.6L since I am not familiar enough with the other engines offered in the F-150, but ever since 1997 they have all been equipped with Ford Coil-On-Plug ignition systems.




-Brian

 

I have 1998 4.6L F-150 with Windsor and it doesn't have coil over plug. Who knows, seems like everyone has a different truck!

 

HEHE.... yea you got a point there. I did a little more research and I found different part numbers for the ignition coils so I guess they are different. Notice the quantity next to the year. Learn something new every day. Let us know how you end up dselter! Good Luck

1997-99, (Qty.2) 4.6L En ... F5LY-12029-A
2000-02, (Qty.8) 4.6L En ... 1L2Z-12029-AA

-Brian

 

The '98 4.6L has 2 coild packs. The 5.4 has coil on plug.

 

I had a 99 f150 4.6 with out coil on just the plug wires. It started missing just in the mornings. then i noticed it was in damp weather and rainy days. One day the engine light came on and it was miss firing totally now dealer put on new plug wires it ran great after that. At night take a old windex bottle and lightly spray some water on each plug wire if you have them it will arc if the wire is bad.