Why has my 1985 Ford Econoline 350hp 5.8L with an automatic transmission lost power?

First thing to check would be the timing . You also might want to make sure the converter didn't come apart internally & stop up the exhaust pipe or muffler ,a simple flow check at your local exhaust shop can tell you this . Pull 1 or 2 spark plugs out & look at them , if they are black & sooty looking then you have fouled your new plugs because it is running too rich-dumping more fuel than it can burn ,probably bad accelerator pump in carb. By the way your 5.8 is 351 c.i.d. and only had a little over 200hp from factory.

1985 Ford Econoline Van

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RE:

Why has my 1985 Ford Econoline 350hp 5.8L with an automatic transmission lost power?

I purchased this van a year ago and it's always had this problem, but has never bothered me because I'd just drive around town. Now I'm packing my things and driving to Alaska. So, I'd like to fix the loss of power. The van can do 55-65 mph on the flats, but once I get going...

One of the things you may take a look at, which is quite common even in today's Fords, is the intake manifold. You have replaced all of the spark. You have cleaned out most of the carbon. But did you know that even a fracture in your intake manifold could cause your engine to loose essential vacuum and pressure it needs to drive? I ask this as a mechanic of 17 years. You may look at replacing and resealing the air intake, which will be located directly under the carburetor. I would also recommend a product call "Restore", which you can purchase at many local parts suppliers. It is a liquid chemical which you add to your oil. (do not overfill your oil pan, drain the amount on the bottle out of your vehicle, and then add.) This chemical is known to help reseal your rings, valves, and even reline your piston walls. You will have a greater sense of compression on the vehicle once you use this product. I used it in my 83 Cutlass 3.8, and it worked wonders. Just add it to your vehicle every time you do an oil change, and substitute the "Restore" bottle quantity for your engine oils total capacity. Try these simple things, and you may see a boat load of change. I changed the upper intake out on a 2000 Explorer just this past Friday. As soon as we did our tune up (plugs, wires, new coil module, air filter, belt, trans flush and filter) this truck runs like brand new again. The last thing I did was the intake, to show my partner and the customer the amount of power you can lose from a faulty intake. Good luck in your endeavors, and have fun in Alaska. Make sure you get yourself some tires, and you may even look into stud capable tires for their roads.

HI

first the motor may be tired... if its a stock motor it does NOT have 350 hp.. I'm think your motor is a 360 cu. inch. Ford does not make a 350 cu. motor.. even tho 5.8 figures out to 350cu its closer to 360cu.

You might check the timing it could be off.

good luck

tim

OOPS.. I FOR GOT ABOUT THE 351CU.