beefy350

Okay guys, this is my first post here, despite lurking and using knowledge shared on these forums for years. But I'm I desperate need of help and despite searching I've come up with no solid answers. Let me start from the beginning. I use my z to go drifting, it is the second 350 I've owned and I bought it knowing it needed some love but that was okay because the price was right. Last season, late in the year it started smoking (alot) at WOT and losing power. So I gave the old engine a good thrashing before parking it and tearing down to find the problem. long story short it was pretty bad. Could have been rebuilt at great expense, but that's not really worth it to me when the rest of the car was stock and I needed to have it at least mostly prepped to slide for the '15 season. Soooo I bought a used engine from slidegood, as they are a reputable company and stand behind they're parts, and started putting the ole girl back together. I gave it a bunch of basic bolt ons including intense power long tube headers, unorthodox racing underdriven pulleys, kinetix ssqv manifold, z1 motorsports clutch & flywheel, injen intake, and a handful of new gaskets and sensors while it was apart. Now, it starts and runs, but let's out a pretty loud backfire every few seconds while idling and throws code P0335 for the crank position sensor. So far Ive put a new (aftermarket) sensor in, tried another stock sensor, it has all new plugs, firing order is right, timing is right, idle relearn is done, and I haven't gotten anywhere. Today while running I started unplugging coil packs, these are the same coil packs that were on the old engine and gave me no problems. But when I pulled the plug for cylinder 4 the backfire immediatly stopped and then restarted when I plugged it back in. Checked compression, all is well. So, could this simply be a coil pack, or am I just finding the fault caused by something else amiss? I've tried everything I can think of here and much more than I care to outline in this post but does anyone have any ideas? I'd appreciate any help and I hope maybe if we solve this someone else down the line with a similar problem gets to search up this thread and find some answers. thanks again in advance guys and here's to alot more sharing as time goes on .

qew

iTrader: (1)

Did you ever run the engine before adding on all those bolt ons and changing things you did? It could be that the timing was funked up from the get go. Did you try disconnecting other coils the way you did with cyl#4? any difference? you said when you disconnected the that coil for cyl#4 it went away did you drive it that way to see how it fired and drove? interested to see what happens. try it and get back to us,also try disconnecting other coils,example instead of only four try only six and see how it idles and drives,then 2 etc.

Also you will more than likely need a tune, you are probably lean with those bolt ons . which plugs did you use,what gap and what condition are your plugs in regarding color burn pattern.

With all that said i would focus on causes of that code. let us know how things go,get back to us.Thanks

beefy350

Never heard it run before adding the parts as I wanted to install them while the engine was out and easier to work on. I know it's more than likely lean as hell. But this is beyond a needing a tune type of problem. As far as trying other coil packs, I pulled #2 which immediatly made the car fall on its face, and also pulled 6, which made no difference. Bought a new coil, installed it in #4 still pops when plugged in, and stops popping when unplugged. Switched the new coil in #4 and the old coil in #6 around. Still no differnece. Plugs are gapped to .44 per ngk. I would try driving it, but I need to bleed my clutch before that happens and button up a few other odds and ends before I can put it on the road. Does anyone know who produces the flywheels for z1 motorsports? I remember reading somewhere that another brand (jwt?) produced some that had the alignment dowel 180° off? That's the only timing part I changed and I know for certain it is lined up correctly. I'm at a loss here and seriously beginning to hope it's not a junk engine. I don't believe it is as compression is good, but who knows right?

qew

iTrader: (1)

Pull a couple plugs to see how they look to be burning.compare #4 to other cylinders. Look online to see the different burn patterns and what they mean. Regarding the flywheel not sure about who makes em. As far as the 180* on the flywheel install don't think that would affect timing. As long as you didn't get into the the timing cover and mess with the timing chain, it should be ok. Disconnecting that coil and it stops popping is very odd. When you say popping is it backfiring in the exhaust? Or is it running rough, car shakes?