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Awesome. I was going to change fuel filter anyways. But you recon take fuel line off from front of the fuel rail? How much petrol should I put in to flush it out?

Run through what is in the tank first. Then add a smallish amount and run that through, then repeat. No point adding good fuel to bad in a 50/50 mix and then running half of it through leaving a 50/50 mix of old and new behind.

Keep in mind though that running a tank to the bottom can and will pick up crap from the bottom of the tank, pulling it through the pump (which might not appreciate it) and definitely putting it in the fuel filter. So don't change the filter first, and be careful about how low yo run the tank. It can of course be hard to know how much fuel is actually in the tank!

Just rereading your original post and you said you connected the battery the wrong way. I would get that ECU checked to make sure you didn't fry anything inside when you through voltage up the wrong way considering your lack of spark.

Also I would pin out the coil pack loom and make sure the coils that aren't firing are actually getting power from the ECU.

so i just did a compression test..not looking so good. i dont know exactly what this means but i cant imagine it being good that a few of the cylinders have low compression.im hoping i just didnt put the gauge in properly but im fairly sure it was in properly each time but not 100% positive.didnt have time to retest them all since it was getting too dark. but i put the new spark plugs in. didnt get a chance to test the fuel side yet..of theirs any point now :/

should mention that i haven't changed oil or the oil filter yet. could this cause lower compression ? im guessing it wouldnt make a difference.

google time !!

hrrm im hoping nothing to major. im just reading a few things on google. someone said to put a tea spoon of oil into the spark plug hole of the cylinder with low compression and redo the compression test and if its higher it means the rings are worn out and if it doesnt go higher then its the valves. least thats what im getting from what im reading. i'll redo the cylinders that had low compression tomorrow in the morning.first normal then with a bit of oil in it

yeah i noticed it was the ones next to each other. would that mean head gasket was stuffed before i got it ? or just from sitting ? i;ll be pissed if thats how the guy sold it me

lol - must have been typing at the same time.

answer is yes it could be the HG between the 2 low cylinders

ah now I see GTSboy is on the case above yours

Edited by Sinista32

somewhat freaking out lol. not giving up yet. worth getting a new head gasket? should i try the oil in the spark plug hole first or not bother and get a head gasket

Head gasket is easy fix but not so much if you don't know what your doing. It's a lot of work but not a lot of cost [emoji41]

Find a decent workshop nearby and get a quote to change it for you.

yeah i dont think i would risk doing that part myself.i've seen it done years and years ago but dont want too stuff it up. i might start googling it and watching some videos and then i'll decide if im capable of doing it on my own lol i'm hoping my cousin will come down with his g/f who's an apprentice mechanic. they're both into the nissans but not sure on their skill level. cant be worse then me though lol i'll get onto him though.looking for a head gasket now. any recommendations ?

yeah i think i;ll do the oil in the spark plug test and see if it raises.if not then i;ll look into maybe getting head gasket. if it does rise after putting oil in the hole what would i be looking to do next ? throw it out ? lol

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