I would recommend a 10w40 blend for this summer as it is getting quite warm.. and it also depends on how / where you are driving. If you are doing long trips then I would more than likely recommend a...
ECU could be causing this.. I had an issue with this a while back when cold the car would start fine but when warm, not sure WHY but when warm, you wouldn't get a signal back from ECU after key was...
Check fuses, check globes. Make sure it is all working. Supply power to your fans by using your battery and a 'paper clip' to send power to the fan and ground it to a earth...
Yeah 9V is too low with the headlights off. A GOOD battery should hold OVER 9.6V with headlights ON for over a year. Check it out.. let us know, would be good to know what this could be.
But current .. hmm fcuk what could it be :/ You may have something wired to constant voltage rather than ignition voltage and that is causing power drain when accesories is turned on. Hmm, still...
hmm yeah well something is drawing way too much current if your engine dies when you switch on your lights.. have you checked your battery with a multimeter yet? If not, do so now.
umm to check the ignitor and coils you probably need to test for resistance through each coil and you need to find out what switches the coils to fire to where...
and it will probably be the ecu.
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Yeah the hose from the intake manifold that goes to fuel rail is to the 'fuel pressue regulator' so it will adjust fuel rail pressure based .. well basically based on throttle position.