Bad Acceleration, then brake pedal Hard

[mrgh]

I have a 1999 Contour 2.0 L (DOHC) manufactured on June 10th, 1999. Last week when pulling onto the highway, the car suddenly had virtually no acceleration. It was completely stumbling all over itself and attemting to accelerate produced a throaty drone sound from the front drivers side. Fortunately I did make it back home,(a distance of about 4 miles from where I was).

I shut the car car off in my driveway. It restarted with no problem, over and over again. Reving it produced the same throaty sound and it sounded as if it was not reaching the normal RPMs. When attempting to drive it in the driveway, again it exhibited extremely poor acceleration. When trying to brake the car the brake pedal became hard and it took extreme pressure to stop the car. (I had experienced no brake problems on my drive back home.) The brake pedal felt fine when starting the car and putting it in drive. It isn't until the car starts to roll forward that the pedal becomes hard.

It repeated this behavior time and time again in the driveway. I had a brief problem in the past, ( about a year ago), with the fuel pump when it would not initialize. A couple of raps on the gas tank with a rubber mallet fixed that problem and I never had a problem with it since.

There are no diagnostic trouble codes. All wheels spin free and no brakes are locked up. The upper O2 sensor was removed to check for a blocked catalytic converter, but the Contour ran just as bad, hopefully ruling that out.

After looking through this forum and seeing how 1999-2000 Contours are notorious for fuel pump problems and because of the pump problem I had in the past, I went ahead and purchased a new fuel pump to be installed as well as a new fuel filter and spark plugs. It had no effect at all.

After installing the new pump, the car ran for about 5 minutes and then stalled. It will no longer start at all. It doesn't even try.

Contrary to what is listed in manuals this car does not have a port to check the fuel pressure anywhere i could find next to the fuel rail or injectors. The new pump does initialize when turning the ignition key on. So did the old one. Maybe the new pump ran for 5 minutes and then went bad. I don't yet know. But for that 5 minutes it was running the car ran just as bad as before, as well as the hard brake pedal with a lot of pedal pressure needed to start the car.

Next step will be to see if fuel is passing through the fuel filter, but why the original problem started I have no idea and I'm hoping someone reading the forum might have an answer to the problem. When running, the car can't get out of it's own way. Has anyone experienced a similar problem, or know what is causing the car to run so poorly?

Any assistance is appreciated.

[Davescort97]

Welcome to Automotive Forums.

My knowledge is limited on Contours, but I will post anyway since no one else is bothering to.

The hard brake pedal is almost certainly the vacuum booster on the master cylinder not assisting the brakes. If the booster diaphragm is torn or has a hole in it the brakes won't be assisted. On the same note, you would have a serious vacuum leak which could be causing the car not being able to get out of it's own way as far as performance. I believe there is a check valve in the vacuum line running from the intake to the brake booster. If you take it off you should be able to blow in it one way, but not the other. If it blows both ways or not all it is a faulty check valve. The check valve comes with the hose. You could take the vacuum line loose and plug it to see if this is what's causing it to run poorly. If it clears up the trouble getting a new line with a check valve would solve your problem. Then, of course, this could have nothing to do with your problem. Just thought I'd throw in my 2 cents worth.

[JoeShmoe]

Does it have a CEL? A bad knock sensor will also give you bad acceleration.