Do you think I need a new engine for my 1999 ford contour?

no new engine needed just a tune up.

New spark plugs and plug wires.

Change all filters and fluids

Car might also need timing

Idle screw needs to be adjusted.

if those are done and still no increase in performance the next step would be would to get the distributor check.

There could be a variety of reasons for the conditions you describe. I'd start with a good tune up. However, I don't think you've said anything yet that describes the need for a new engine. If you are that worried about it though, you might want to run a compression test and post back your results. Then we might could tell you more definately. I highly doubt you'll be making a good investment though with a NEW engine. If I was going to invest that kind of money (if needed) I'd rebuild the present engine instead of buying a new one.

Unless there is a NEED for a new engine, I don't believe in replacing them. I go with an overhaul instead. An overhaul is cheaper usually, and more often than not winds up with an engine in BETTER shape than a new one would be. I've seen rebuilt engines last three and four times as long as factory rebuilt or new engines. A good mechanic takes the time and pays attention to details that the factory doesn't give a #@($ about.

It could need an engine timing or another sensor. Contour engines are notorious for being problematic and can cost a bundle to replace. Most likely, one of the cylinders isn't firing properly and it could be anything (and I mean ANYTHING) that causes it. The problem could be related to spark, such as a bad plug, to a sensor throwing the timing off, to a fuel injector that is dumping too much or maybe none at all into the cylinder that isn't firing. Another popular cause of this issue is a leaky intake manifold where the air is getting into the air intake through the seam of the two halves of the plastic air intake and the leak of vacuum pressure will throw the sensors off, because it will be getting more air than fuel mixture and the engine will attempt to compensate by enriching the mixture. Have a mechanic with a vacuum leak detection machine check it over for necessary repairs as soon as possible. Then, evaluate the condition of the car to the repairs it needs as to whether it's worth putting the repairs into over replacing the vehicle outright. Expect to pay at least $100 for the mechanic's time it takes to give you a proper diagnosis.

How many miles are on it? It's very likely that either the catalytic converter is defective or the transmission's torque converter.... or both. My '96 Contour failed the transmission twice. Turned out that there was a design flaw that Ford wasn't being open about. Other than that I loved the car and would buy a good used one with a manual transmission in a heartbeat, if it was priced right.

If it started doing it right after the timing belt was changed they didn't get it on right. They done something wrong and are trying to get out of it. If a valve is sticking they probably bent it if they turned the engine over without the belt on. Get a lawyer.

It sounds like you need some new plugs and wires and new fuel and air filters. It might need a timing belt put in it being that it is a 99. Stretched and worn timing belts with worn tensioners can cause you car to run awful. If you do replace the belt make sure you replace the tensioner also. One of my friends has one just about like yours and he ran over a speed bump which jarred and broke one of his motor mounts. You might want to check those just to make sure.

Good luck.

It sounds like to me that the timing is one tooth off.

It might only need some new spark plugs and wires.