The mechanic replace the timing belt on my car but he cant start it. he recheck the timing alignment, spark, fuel delivery all seem fined per him and there is compression

Several possibilities
1. No fuel
2. No spark
3. Mechanical problem ie, bad timing belt, bad cam shaft no engine compression, etc.

First spray starter fluid into the carb/throttle body depending on car and year. If it starts then you have a fuel delivery problem. Could be fuel pump, pump relay, bad fuel line, bad fuel filter or pulse to the injectors.

If it still does not start then check to see if there is spark at the spark plug. If no spark then a scanner would be the best bet to finding the problem.

First off it's never a good idea to start an engine on brake cleaner so I would get it taken to a real mechanic shop. Second it could be alot of things from fuel pump to a mass air flow sensor. More than likely its a fuel issue. Check all fuses and If blown replace them with same size fuse. Check again to see if it starts if that doesn't work Check the rela for fuel pump you may be able to swap it out with another one in different location in panel see I it works. After this I it still won't start you need a scan tool. Good luck

chain or belt
recheck timing marks on the cam and crank align
turn clockwise twice if the timing marks are out
it wont start and backfire

The best way to assess the fuel delivery is to connect a pressure gauge to the top of the fuel filter, or in line via a t-piece, and measure the fuel delivery pressure. It should be about 40 psi. If low, change the fuel filter, and recheck.

If still low, it is a faulty fuel pump. If OK by the method shown in the link below (ie with fuel rail disconnected), then check the fuel pressure regulator at the end of the fuel rail.

See here p179 and p187

http://www.turboninjas.com/camry/eg1.pdf

Another classic cause of hard starting is incorrect ignition timing. If the timing belt is old, it may have jumped a tooth, so check the timing. See the above link, p18

Check for signals to injectors to make sure the computer is telling it to inject.

look man a mechanic is a guy who can change parts on ur car till it fixes it u need sumone to trouble shoot y did u change timing belt did it skip teeth good one day next start wont sounds more electrical or ignition do u have alarm system

Have a look at the fuel filter bro.

The crankshaft position sensor (CKP) and Camshaft position sensor (CMP) work in harmony to control the spark/fuel delivery and timing. They both consist of a reluctor, or tone, ring which passes over a magnetic sensor, which generates a voltage, indicating position.

The crankshaft sensor is part of the primary ignition system and functions as the "trigger". It detects the position of the crankshaft relays that information on to the PCM or the ignition module (depending on the vehicle) to control spark timing. The Camshaft position sensor detects the position of the camshafts and relays the information to the PCM. The PCM uses the CMP signal to identify the beginning of the injector sequence. What ties these two shafts and their sensors together is the timing belt or chain. The cam and crank should be precisely timed together. If the PCM detects that the Crank and Cam signals are out of time by a specific number of degrees, this P0016 code will set.

Causes may include:
Timing chain stretched, or timing belt skipped a tooth due to wear
Misalignment of timing belt/chain
Tone ring on crankshaft slipped/broken
Tone ring on camshaft slipped/broken
Bad crank sensor
Bad cam sensor
Damaged wiring to crank/cam sensor
Timing belt/chain tensioner damaged

First, visually inspect the cam and crank sensors and their harnesses for damage. If you notice broken/frayed wires, repair and recheck.
If you have access to a scope, check the cam and crank patterns. If a pattern is missing, suspect a bad sensor or a slipping tone ring. Remove the cam gear and the crankshaft harmonic balancer and inspect the tone rings for proper alignment and make sure they're not loose or damaged or that they haven't sheared the key that aligns them. If they are properly installed, replace the sensor.
If the signal appears normal, then check the timing chain/belt for proper alignment. If it's misaligned, check for a damaged tensioner that may have allowed the chain/belt to slip a tooth or several teeth. Also check that the belt/chain isn't stretched. Repair and recheck..

Theres a lot of covers etc to take off to get replace the belt. I would first have the timing checked. Then have them recheck their alignment of the three belt gears.

check your ignition coil and plugs for sparks. if no spark replace. if the rotor is turning then the timing belt is fine. rotor in the distributor cap. 3 screws will get you in there.