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Was hoping to find useful info or jack someone else's related thread before I made this but no luck so here goes:

Was having terrible misfires awhile back on my GTT, had it diagnosed and replaced the coils with Splitfires and also replaced the plugs and the misfire problem has gone. Which is awesome.

My question is, I barely had an instant ignition when I turned the car over, 1-2/3 chugs before it ticked over before I had splits. When I first popped the splits in, BAM, first go, which was an awesome feeling.

Now I'm back to the 2 to 3 chugs, rarely ever getting that unicorn-like first turn instant ignition feeling. Would it be worth gapping the plugs back down (0.8 before problem, 1.1 once the splits went in, using Copper NGKBCPxxES-11 or whatever) to 0.8 again or could this be attributed to something else?

Gapping the plugs down is free and worth a shot.

When did you change the battery last?

Back to 0.8 you reckon or? Just a lot of work for me to get to those plugs (I'm novice), great practice though!

Didn't even think of the battery.. can an old battery really have that kind of impact? I just figured it'd be drawing more current from the alternator and not affect the actual spark

Back to 0.8 you reckon or? Just a lot of work for me to get to those plugs (I'm novice), great practice though!

Didn't even think of the battery.. can an old battery really have that kind of impact? I just figured it'd be drawing more current from the alternator and not affect the actual spark

alternator replenishes the battery but its the battery you draw on when starting.

Yep defo check the battery mate, a new one helped with my starts.

Another thing to check is any dodgy leads off the battery, I had a really bad bodge job connector off my plus terminal that kept cutting out randomly and the car stalled in traffic (it was auto back then). It took $100's and lots of gray hair to diagnose it because it was so obvious everyone overlooked it :/

Also my misfire saga writeup is here, might have a couple of other pointers: http://www.sau.com.au/forums/topic/326043-resolved-misfire-in-r34-gtt-rb25det-neo/

Edit: How's your idle with the Splitfires, 100% no hiccups? I'm thinking of potentially replacing my current YJ's with them...

give it more choke on startup.

But sizzirslsy, I get that every now and then, the turn and bam start, but most of the time it's a few chugs. Unless you put brand new plugs in every week, you might be chasing shadows?

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Has there been a change of season since its gone back to struggling to start a bit more? Could be tune related if you have an aftermarket ECU.

I'd also recommend changing the battery if its old/unknown age

Yep defo check the battery mate, a new one helped with my starts.

Another thing to check is any dodgy leads off the battery, I had a really bad bodge job connector off my plus terminal that kept cutting out randomly and the car stalled in traffic (it was auto back then). It took $100's and lots of gray hair to diagnose it because it was so obvious everyone overlooked it :/

Edit: How's your idle with the Splitfires, 100% no hiccups? I'm thinking of potentially replacing my current YJ's with them...

Yeah pretty awesome. My whole misfire saga was a nightmare but they really saved my life, so much better performance-wise.

Will gap my plugs down to 0.8 and report back. Guessing it's the battery also but process of elimination will get me there in the end.

Cheers for the pointers guys

Stock fuel pump or aftermarket?

I put a Bosch 040 in my R33, f**king thing didn't have a check valve in it. So the fuel empties out of the fuel lines back into the tank when you leave it sitting overnight. It would never start properly unless I let the pump prime for 5 seconds first.

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