Hi guys im back with this starting problem..well i have replaced battery as when i was trying to start car asc kept saying inoperative.so you guys said replace battery and so i did and problem solved .but i bin monitoring the starting problem and some times in a morning from cold it starts first time but most of the time takes about 5/7 seconds then fires right up.and this is the same when warm but all the time when warm.only thing that has throwed up on diagnostic is left side up stream lamber sensor.which i have but not fitted.no other codes.so what is mostly like to be the cause plz guys.

 

Fix any code fast in case it is masking any other(s).

Have you changed the timing chain tensioners etc? You can expect a dead engine sooner or later if not.

 

Hi yes i just completed timmming chain set all done and was i lucky all tensioners were ready to fail big cracks in them and the guides were all breaking up to.

 

Fix the known fault and see if it also fixes the starting one.

 

One possibility is the Camshaft Position Sensor which some cheaper scanners do not detect. Do the following test: before attempting to start, keep the key in the ignition "ON" position for 40-45 sec. If, after that, the engine starts immediately every time, it could be the cam sensor(s).

 

Do you know history of fuel pumps -- known failure point. You could have a fuel problem -- do you hear the pump start ? Check the fuel pressure.

 

For hard starting, maybe clean the MAF sensor, clean the throttle bore and plate, tighten all joints on the intake tube. How old are the plugs? Try a can of Gumout, Lucas, or SeaFoam cleaner to clean up the injectors.

Oh, yes, change the oxygen sensor that is throwing a bad code . . .

Maybe, after testing the fuel pump (listen for its whine, check for pressure at the shraeder valve), change the fuel filter.

Also, some folks have noted a starting problem in cold weather caused by a bad temperature sensor in the crossover pipe. If the sensor is bad, it will fail to tell the ECU to enrich the mixture (or will show the engine is cold when it is warm and will over enrich).

Usually if the engine is turning over for five to seven seconds, it is not the battery.

 

Just looking at the fuel line check valve you can put a pressure gauge on the shruader valve and see if it holds . The pump may need more time to get the fuel pressure to the needed value if the trapped fuel pressure is lost . Without the fuel pressure test you can see if it holds pressure during a quick series of starts and shut offs vs. a longer period of time between starts and shut offs which may require the longer fuel pump priming .