Recently purchased a vitara 94 model, however when you drive the car it almost feels as though it looses power for a split second causing a shudder. What Can i do to solve this problem

not knowing the quality of workmanship used in the engine rebuild, it is difficult to answer exactly what is wrong
plugs and leads will not be faulty
I think the clue is in the remark about the carby being replaced and it ran a bit better
that indicates ,along with the very rich settings, that it could be an valve timing problem
I suspect that the cam shaft lobes are damaged or the timing chain gear is loose on the cam shaft
running well in the beginning and then slowly failing all points to the cam shaft lobes, cam followers or loose cam gear

Have the crank position sensor checked. This sounds very familiar.

If the problem is due to warped brake discs, you will typically feel a mild pulsing in the peddle when braking firmly. Also, when you are experiencing this shudder, taking your foot off the brake (when safe to do so) should cause it to stop. If that is not the case, I would consider again the transmission. I am on my second Caravan, so I speak from experience. The Caravan transmission should have the fluid changed every 30,000 miles to keep it in top performance, especially if you are carrying any heavy loads or pulling a trailer. When you are slowing to a stop, the transmission must downshift through each of the gears. If it stays in the higher gears at too slow a speed, you will feel a shudder. Sometimes this can be corrected by changing the transmission fluid. Be sure to use the proper Chrysler fluid for your transmission. Typically it is the highest (overdrive) gear that causes the shudder. You can determine this by moving the gear selector from "D" to "3" when you are experiencing the shudder. Other possibilities are alignment, worn stabilizer bar bushings, worn ball joints, and out-of-round tires. Most of these also involve some accompanying noises though. Good Luck.

Well, you did a really good job of describing the symptoms, but you didn't do so well describing the car. Are we talking about an automatic or standard transmission? are we talking about a four or six cylinder engine? You are asking about a drivetrain problem without giving any information about what drivetrain the vehicle is equipped with.

With all that said, IF we are talking about an automatic transmission being pushed by a V-6 engine, then there is a Technical Service Bulletin (TSB) that matches the symptoms you are describing. In this case, the problem is most likely being caused by a deformed or damaged exhaust pipe "A" mounting bracket.

Inspect the rubber bracket for cracks or torn rubber. If the bracket is damaged replace the bracket. Bend the stud on the exhaust pipe if necessary to get the stud to go through the bracket as straight as possible so the stud does not "ground" against the sides of the bracket. (see diagram)

have checked the play in the distributor shaft gear . excessive play can cause a timing problem for a moment. also has the service engine soon light came on with a code 42 for the ignition system. ignition control module can cause this concern also.

When shifting into drive you are applying the brakes to do so. Using your breaks is one of the most power consuming things the car uses. Check the cars battery. The connection between the wires to the battery are either loose, corroded, or just extreamly dirty. If none of these apply, you may just want to get a new battery. I myself had the same issue with a 2006 Kia Optima. If you haven't replaced the battery since you got the car, you may consider doing it anyways as it is well past due.
Good luck! :)

have the system tested for fault codes, i think u will find that u have a misfiring cylinder

Very difficult to diagnose a shudder in a vehcile if you are not there to "feel" what it is doing but here are 2 possibilities. First your drive line may have a u-joint going out and if its a 4X4 dont overlook your front drive line and second you may have a tie rod or a ball joint that is worn causing your shudder. either way it would be important for you to address this issue quickly

there is a few things that could be wrong. 1: check if your fuel filter is clogged or your fuel pump is clogged or just going bad. i would check the filter first, only cause its alot cheeper. 2: check if your o2 sensors are bad and needs replaced. 3: check if your air mass sensor is bad. i would check the easiest first and the pump last.

Just guessing. Could it be a warped brake disk? That would cause vibration. And vibration in steering might conceivably cause splashing out the power steering reservoir. You would know if the disk were warped by a shudder when you brake at hight speeds.