2006 Suzuki Reno • 4 cylinder FWD Automatic • 68,000 miles

I recently just had to replace the engine in my 2006 reno at 65000 miles, upon having a used engine with 68000 on it, the check engine light has not turned off. I got the codes ran and it says cylinders 1 and 4 are misfire. Had the ignition coil replaced did nothing, removed the valve cover found out the shop put it champion spark plugs so I replaced them with the right ones (ngk) Nothing. The check engine light stays on all the time but everytime the car exceeds 60mph the light starts to flash. I turn the car off and restart it, and it stops, tested it again, drove its for 30 mins at 55 mph no flashing, but as soon as I gassed it over 60mph in about a minute it started flashing again, any ideas, the engine has only been in for less than a month, sounds great but gas mileage is extremely below normal and car seems to struggle with power. Really could use some help.

January 29, 2011.

Check the those cylinders compression and injectors, test the coil/s and the crankshaft position sensor

Jan 29, 2011.
Well the New coil was put in 3 days ago and I have no codes popping up for the crankshaft position sensor, is it possible it could fail without a code?

Jan 29, 2011.