Questions and Answers

Ford Windstar Severe Power Loss Q. I have a 1998 Ford Windstar 3.8 liter engine, automatic transmission with overdrive with a fuel problem that hasn't been able to be diagnosed. When the car is cold, it runs fine. Once it has run for awhile, about an hour, it has a severe loss of power, with no acceleration whatsoever. Another observation, even when cold, the engine starts to break up around 4,000 rpm.

When hot, it breaks up around 1,500 and has no power. We were on vacation when it first happened and a dealer supposedly diagnosed it (but I didn't get the codes). They said it was either a clogged fuel filter, an inoperative or clogged EGR, or bad fuel injectors.

I replaced the fuel filter, removed the EGR, all clear there, and removed the injectors and cleaned them. They all seem to be operating and are in-spec for ohms. I checked fuel pressure and it is just below spec for all readings. Replacing the fuel pressure regulator did no good.

The car idles fine, even when it has no power. It seems to be an electrical sensor that gets too hot and fails. Problem is that when the car cools off, it seems to work fine again. I doubt it is the fuel pump itself since it is far from any heat generating parts.

Not having an OBD-II tester, I haven't been able to diagnose it. And when the dealer finally gets around to checking it out, the car has cooled off too much and they don't seem to want to take the time to get it hot again. The car has 72,000k miles on it, it has P/S and ABS. Any ideas where to continue looking?

A. I would look for a fuel line (hose). Sometimes the hose will tend to collapse and it could cause this same problem. Or it could be that a hose has a piece of rubber that closes of the passage way.

In the computer there is a fuel diode, it will case the very same problem. I have a 1998 Ford F150 in my shop. He had been to everyone with no luck. I opened up the computer and tested every diode and found the fuel mix diode to be bad. He put in a new computer and it solved the problem.

I would also not rule out fuel pump. Ford Fuel pumps start going bad at about this milage.