Need help! on my 03 Lancer ls, no power on one coil pack side

the marks on the cam shafts are directly vertical at the top in line with a mark in the back of the housing the balance shaft timing mark is at 9 oclock position
the crank shaft timing mark is at 10 oclock position ( lining up with a pointer) and the oil pump mark is also at the 10 oc;ock position lining up with a pointer
( to check the position of the oil pump sprocket remove a plug -shown in the book -and insert .30dia pointed screw driver (5/16 philips ) to at least 2.4 "
if it cannot be inserted to this depth move the oil pump sprocket until it can)
the process of assembly is -:
install the timing belt to the sprockets and pulleys in the following order , retaining the belt to the camshaft sprockets by the use of suitable binding clips ( clothes pegs etc)
crankshaft sprocket
oil pump sprocket
guide pulley
exhaust camshaft sprocket
intake camshaft sprocket
tension pulley
to help install the belt the auto tensioner on the lh side should be removed
all of this information will be included in a workshop manual covering lancer engines for the years listed and will also include all tensions for the bolts --If you do not have the workshop manual then it is STRONGLY recommended that you obtain one
information from autodata belt installation manual lancer 2.0 l
2003-2007 engines

Maybe the timing belt it's out of timing. Check video.

DRAIN COOLANT SYSTEM.DISCONNECT THE RADIATOR INLET HOSE FROM INLET PIPE. REMOVE THE TIMING BELT FROM THE WATER PUMP PULLEY. REMOVE THE RIGHT SIDE IGNITION COIL.REMOVE THE WATER INLET HOUSING AND THERMOSTAT.REMOVE THE MOUNTING BOLTS AND STUDS. LIFT OUT THE WATER PUMP BY CAREFULLY PRYING BETWEEN THE PUMP AND THE CYLINDER HEAD. REMOVE ALL THE OLD PACKING AND CLEAN THE MOUNTING SURFACES. INSTALL NEW SEAL PACKING TO THE WATER PUMP GROOVE AND A NEW O - RING TO THE WATER BYPASS PIPE.INSTALL THE TIMING BELT AND CONNECT THE INLET HOSE TO THE INLET PIPE.THEN REFILL THE COOLING SYSTEM. RUN THE ENGINE CHECK FOR LEAKS.

With the belt off and the tensioner pulley pushed back, you will need to set cylinder 1 (far passenger side) to top dead center. There is a mark on the block you can see just behind the crankshaft gear that needs to be aligned to the mark on the crankshaft gear. CAUTION NOT TO TURN THE CAM PULLEY TOO FAR IF ANY PISTONS ARE AT TDC, they will contact the piston on this motor. turn the crankshaft gear forward or backward 1/4 turn off of TDC when you move the cam pully. Once this is done, you will need to set the camshaft pulley to a poorly designed mark on the cylinder head. (it is the corner point of the casting for the cylinder head, it forms a triangle at about the 10:00 position when looking at the cam pulley). Install your belt, it will be tight even with the tensioner pulled back so making sure it doesn't cause either of the gears to move off their marks. Once it on recheck the timing marks upper (cam) and lower (crank), release the tensioner, put your other belt on and you're done. http://www.mivec.co.nz/tech/4G9x_Engine_Manual.pdf

check coil packs and ignition controle module,some can be bench tested at parts stores

Driver side valve cover
7mm socket to remove coil covers and coil

1 thru 4 pass side
5 thru 8 drivers side
Front to back

YOUR CAR ONLY HAS COIL PACKS. CHECK VOLTAGE AT HARNNESS, IF OK REMOVE COIL PACK FROM SPARK PLUG REMOVE BOOT CHECK FOR VOLTAGE THERE, IF NONE POSS. COIL PACK.

try putting on a thicker rubber seat for your coil springs to add height. hope this helps

I dont think that u have a timing probing but just to be sure I would recheck the timing, (remove timing belt cover, set crank to zero and make sure both cams line up with the marks on the engine) if thats all good the u have a prob with that particular cylinder. first thing I would do is swap the coil pack from cyl 3 with another cylinder (like cyl 1) then start the car if the misfire code goes from P0303 (Cyl 3) to P0301 (Cyl 1) then u know u have a bad coil pack. try that and let me know what happens

Most likely what has happened is that when the thermostat went out the engine over heated and the seal of the valve gaskets to the plastic valve covers got warped and you ahve oil the has dumped into the coil pack area and it has caused 1 or more of the coil packs to go bad as solution #1 has explained. get the gaskets replaced, it sounds like your husband is handy. Its not a difficult procedure just a little time consuming. research the coil packs because at the dealership they are very expensive. People have had alot of good luck buying them on ebay.