I bought a 1990 F150, 5.8 L, 4x4 last July. Since I've had it, it has run not quite right.

I took it to the local shop. The put some sort of scope on it, said it was cross firing. They charged me for their time and adjusted the wires. It ran great for a day. Very smooth, accelerated nice. After it was back to its old self, I tried adjusting the wires by randomly moving them, hoping to get back to that nirvana I had for a day, no luck.

Next, I changed the plugs, wires, cap and rotor, still not quite right.

I was at the local shop for a tranny flush a few months later. Told them it was still running not so great. They said ‘buy these plug wires’, high quality, it will work. It worked great for a day and a half.

I gave up, figured I'd look into it this summer.

I took the truck to a local Ford dealer last Thursday, told them to take a look at the idling issue, along with other stuff. Ford says new cap, wires, and rotor. The tech said the rotor looked a little more burned than he would like to see.

Instead of paying Ford a years wages to change the wires, cap and rotor for me, I purchased the cap and rotor from them and threw them in. In my opinion, the old rotor didn't look burned.

So now I'm not sure what to look at next. Could there be some other underlying issue? I don't think it should be necessary to buy racing wires or other super high quality wires since it's a daily driver, but will if someone can recommend a brand they think will help.

Would changing the ignition coil help any, or would that be more wasted money?

Thanks for any help,
Nathan

 

See the thread below called " Plug wire question"
It might answer your question.


[b][i][font color=red]Dennis[/font][i][b]

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