cant go past 5500rpm

[blk240s14]

ok i just got my s14 swap done.. i have a 96 240sx with a s14 motor in it and it runs fine but when i get to about 5000 or 5500rpm it just starts to break up and me and my mechanic have checked almost everything so im stumped.. im new to this site so i just thought maybe you guys had some ideas of whats goin on.. thanks

[Emperor_Tha]

Are u running a upgraded fuel pump and filter

[blk240s14]

naw its just a stock sr20 i havent upgraded the fuel pump or filter but im thinkin it could be fuel injectors so i put some fuel injector cleaner in it and ima run it for a few days to see if that helps any.. got any other suggestions?

[Emperor_Tha]

boost leak? I would highly recommend at least running a 300xz fuel filter since it like 15 bucks and take 1 min to install

[blk240s14]

aight ill try that and let you know if it helps thanks!

[JDM_RPS13.5_SR20DET]

i kinda got that problem on my s13 sr20... after i hit about 4500 to 500 rpm at WOT it boggs and sputters but if i let it climb on light throttle its fine. i have a high flow pump but a fairly old stock fuel filter and stock injectors?? any help

[Emperor_Tha]

upgrade the fuel filter first.....try to clean fuel rail for anything crink or dirt. cheak fuel pressure with the gauge and see if the fpr is working.

[JDM_RPS13.5_SR20DET]

ah thanks!

[blk240s14]

thats exactly what mine is doing so ima replace the filter and check the fuel rail.. im thinkin its a fuel problem but im not sure if it is or not.. any other ideas what it might be besides fuel related?

[Emperor_Tha]

Boost leaks? When u install the fuel pump make sure u use a hard clamp to strap the fuel pump to the base. They tend to move around with the zip tie.

[JDM_RPS13.5_SR20DET]

yeah i thought it could be a boost leak but i have all new gaskets on the intake manifold including throttle body and i have pressurized the intake side but its good. the only other thing besides fuel system is a cylinder compression test because i am burning some oil. but i think that would lead to more power loss than i have.

definatly gunna redo my fuel system hopefully that clears up the issue

[blk240s14]

ima redo my fuel system also and see how that goes.. keep me posted on how the car is doing and ill do the same..

[JDM_RPS13.5_SR20DET]

yeah hopefully i can do it in a month.. so i might revive the thread or maybe start a new one hopefully it all works out because i would like to get a front mount soon to!

[Kitswa]

SPARK PLUGS

Check your plug gap, make sure they are the CORRECT plugs.

[JDM_RPS13.5_SR20DET]

mine are a little heavy i have the nkg iridium factory gapped to .044 i think stock for the sr20 is .030 but the spark plug manufacturer says not to regap
Modified by JDM_RPS13.5_SR20DET at 10:32 PM 5/9/2008

[Kitswa]

If you are running 44 or higher gap, you are almost certain to have ignition problems over 5500 rpm.

Regap to 28 and you will see a huge improvement.

15 minute free fix for your problem, save that fuel system money for something else.

- Bill

[moyea]

I run the factory gap on my NGK Irids and there is no reason to mess with the gap on those plugs unless your misfiring, which on a coil-plug setup misses are pretty rare.

If your running a SR20 you need to replace that fuel pump with a high flow one and change that filter to z32. Also make sure your tank is full with PREMIUM (91+)gas. Check that fuel pressure and FPR. Use some seafoam or whatever to clean out those injectors, crank, and intake. If you just installed this engine make sure you do a couple oil changes to get out any particles, gas, or other baddies that could mess your compression. And besides the boost leak check, double check for exhaust leaks especially before the turbo. Also check the ECU for codes.

All this is real basic trouble shooting.

[Kitswa]

Yes, he says he is misfiring over 5000 rpm, that is why he started this thread.

Factory gap on Iridiums and Platinums is usually 28-30 right out of the box.

- Bill

[moyea]

breaking up is a general term and could mean anything. But if he was missing he would know.

The Irid pre-gap of .044 was set for the SR20DE, if you buy them at a U.S. parts store. Which is fine for the SR20DET. The direct-fire coil system of the SR is a pretty poweful stock ignition system. If you are missing, I would look at the ignition components before I started playing with the spark plugs. Playing with it couldn't hurt but make sure you know what your doing because the electrode is easy to break. And most SR owners are running a much bigger gap then .03, usally .08-.06. It depends are your set-up.

[Kitswa]

Jesus, all I see is arguments and wrong info again on NICO.

I've been working with SR turbos for 10 years.

Moyea - you don't know what you are talking about. You sir are almost 100% incorrect in every statement you just made.

gap 45 = misfiregap 28 = no misfire

Good luck y'all, I'm done wasting time trying to help NICO people just to be refuted by inaccurate info at every turn.

- Bill

[blk240s14]

i was out of town this weekend but i def came back to a lot of information.. ill check my spark plugs again and see if that helps... thanks for all the help

[blk240s14]

another thing is when i free rev at about 3500rpm you can hear it startin to sputter and pop.. when im in wide open at 5500 rpm you can really hear it the most.. just wanted to add a little more info and maybe that would help out some.. thanks for all the help im hopin i can get this fixed soon.. if you have any other ideas i would definatly love to hear it.. im thinkin it could be a bad injector but im not sure.. we checked the spark plugs twice and gapped them twice.. but im open to listen to anything i just wanna get this fixed.. thanks again for the help

[adrianfromthecastle]

defintely check out the spark plugs.

because your problem sounds very familiar to my old problem... around 5k rpms it would break up at WOT....

so I popped out my plugs and found this

[blk240s14]

ohhh yeaa i definatly need to check the spark plugs then.. after you replaced them did the car run right?

[adrianfromthecastle]

oh instantly!

here, read this:http://pdm-racing.com/features/plugs.html

[blk240s14]

thanks for the info.. ill def check out my plugs and ill let you know how everything goes... hopefully this will fix it