I bought this '83 F150 Super Cab 4x2 with 155K on the odometer last fall. When I bought the truck is was idling fine, ran well and was economical. Suddenly, a few weeks ago it began to idle poorly and miss while accelerating under load. I purchased a new cap, rotor, plugs and wires. I also broke out an old Craftsman timing light I haven't used in years.

Today I pulled the old cap and saw corrosion under the plug going to the coil. I also noted that moving clockwise, from the #1 plug on the cap the numbers the previous owner had written for the wires went 1-8-7-3-6-2-4-5. Now I know that's the firing order but from what it states in my 1983 Truck Shop Manual the wires should connect to the cap from 1-8-4-5-6-2-7-3.

What am I not getting? I hooked the wires up to the cap the way it shows in the manual and it ran awfully. I went back and tried it the way the previous owner has it and it was no better. I have an '86 VW Jetta that the previous owner had installed the timing belt a couple of teeth off and used the distributor to compensate. Until I installed a new belt I could never get that car to run properly and I'm beginning to feel a sense of deja vu (but why would it have run so well up until a couple of weeks ago?).

Any thoughts would be appreciated.
Thanks,
Paul

 

Ok, upon more careful examination, the shop manual was indicating the order for 5.8L not 5.0L engines. I went back and carefully switched the wires and now it seems to be running ok. Coming from Rovers that ALL used the same old Buick 215 engine I never had to be mindful of changes between the different sized V8's.

Not an auspicious first post!

 

If someone changes the camshaft, the 302 can have the 351w firing order likewise the other way also. The factory actually did this, the 302 HO does have the 351w firing order. Welcome to the world of Fords. If they could mix it up they will do it. Their foundry must have done a lot of work, with all the bellhousing patterns and totally different engine castings that they made through the years.