KA-T Breaking up in boost

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StryfeS13
Posts: 517
Joined: Sun Dec 20, 2009 1:55 pm
Car: 1993 Nissan 240SX
Location: Fresno, CA

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So I did some searching around and I think that it may be my spark plugs?

Here's my problem; Has a slight miss at idle, and breaks up the second it hits boost, like no power, no anything.

I'm running a T25 setup on stock psi, everything's new, I just checked all the intercooler piping and it's solid, no leaks. I have timing @ 15BTDC to be safe, and a 6:1 FMU. (Yes I know, give me ****, but this setup is temporary until I get tuned)

I'm using the BKR6E NGK plugs, FRSport told me they were already pregapped, so I just installed them. Could this be my problem, should I gap them down? I've heard to go .028, or 0.28...so is it .028 or .28?

Thanks...also the car is running an open downpipe but I don't think it'd make it break up like this.


xxoreolovexx
Posts: 28
Joined: Sat Mar 06, 2010 8:00 am
Car: 1997 s14 kouki KA-T

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yeah man first thing is to gap those down .028, and then check you timing again make sure that it is absolutely correct. Unhook your tps and check it per fsm. What do your plugs look like? are they fouled or wet? It may be dumping fuel because that 6:1 fmu can dump too much fuel. Check the easiest s*** first.

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float_6969
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Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
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You can try gapping the plugs down and see if that helps, but you won't usually see ignition breakup until you're running at least 5-7psi. If it's breaking up as soon as it gets into boost, I'd be more likely to think that your FMU isn't setup correctly and you're leaning out at the vac-to-boost changeover point. This is a common problem with FMU's unless you get an really nice one that has an adjustment for it.

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sunnys14
Posts: 1600
Joined: Sun Dec 05, 2004 8:59 pm
Car: S14

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Pull your plugs to see if ALL the plugs are set to the same gap. I used have a random misfire at idle and it turned out one of my plugs was gapped a closer than the rest. Try .030 gap first and if you still miss, slowly gap closer until it doesn't anymore.


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