Corolla 1.4 intermittent starting

skj

Hi
My Corolla (1.4 L , 2003 ) was driving ok , last week it showed misfiring like . then once it starts it runs ok , and after switching off ignition key it can start again , but if gone for a drive , come back and switch off . then it wont start again.

my mechanic did the computer check nd it showed cam sensor ( at the bottom left front ) i think crank shaft one ) cleaned it and put it , checked all coils, plugs , all ok.

when it s cranking but not starting , theres no power coming to ign. coils or even to fuel pump.

mechanic says even immobiliser , all electrics all working ok.

and came to conclusion that the timing chain needed to be changed, since car has done 119000 miles then chain would have got slakness and while slipping clutch ( jumping ), timing chain would have jumped further a teeth and thats causing it not to start intermittent. and he suggests new timing chain to be put.

any one in the industry who knows about those engines could help me ?
i am confused with this concept , how could timing change like that ..and even if it changes then will it start? once it starts i did not notice any missing , i meant engine runs flowless. but at one stage i noticed engine gaping fraction of second at an intervel of 20 to 30 secs . but it just cleared after some time.

jimgoose

The correct procedure here is, after putting the crankshaft position sensor back on, clear the fault-code see if things improve, anor d if the fault-code reappears. If the latter, I'd be inclined to meter out the sensor properly and possibly replace it.

skj

thanks JIMGOOSE,

did both as you mentioned, still happening same. thankyou

PADRAIC.M

Could you please post the fault code as you first said cam sensor then removed crank sensor!? usually a slipped chain would have been nosey last few weeks and can be checked before replacement. Line up the mark on crank pulley with zero mark on casing and if you remove top rocker cover 2 marks line up on chain sprockets, if these are off then change only, more than likely its related to the fault and not your timing

skj

I will check it again today and will post the codes found. I think you are right, will check the timing marks first.
Thankyou PADRAIC

joujoujou

Stretched timing chain often gives camshaft/crankshaft sensor fault code, but you'd also hear chain rattling, especially on very cold engine.

Speaking about the chain itself...

http://s22.postimg.org/aakfxxe69/00_2zzge.png
http://s22.postimg.org/u6gfdgv7l/01_2zzge.png
http://s22.postimg.org/ycwof25fl/02_2zzge.png
http://s22.postimg.org/lcpiwd88x/03_2zzge.png
http://s22.postimg.org/jyxw128zl/04_2zzge.png
http://s22.postimg.org/db1aegphd/05_2zzge.png
http://s22.postimg.org/ylyuiq7lt/06_2zzge.png
http://s22.postimg.org/ls0spdu69/07_2zzge.png

...above showing 2zz engine, but timing in 4zz is almost the same.

skj

Hi Jou,

Really appreciate your effort to write down wiith the above links which is very helpful for me in understanding it very well.
I erased the fault codes and it started but again same would not start

but i didnot hear any rattling noise or abnormality in the engine side
so i doubt it could be crank shaft sensor or some other electrical and checking one by one again..
I will let you know the status..


Thankyou so much
SKJ