my first street tune... problems

[sunnys14]

i did my first street tune today. started out at 3am, 3rd and 4th gear pulls on the freeway here are some problems that i found...

- at 5500 rpms and higher, the car sputters and starts jerking- above 5000 rpms i start to boost creep to about 10 psi!- a nasty ticking noise when i step on the gas... (must be exhaust leak? or rod knock????)

my previous setup was a 12:1 fmu, and smaller FMIC and 8psi. now im running a huge 31x12x3 intercooler, upgraded to 370cc and safc2 and plx wideband. i have never boost creeped b4... why did it start now?

[KATwo40]

What are you using for boost control?

Most likely your ticking is an exhaust leak. You can test for knock by doing the following:Sitting still idling out of gear, give the car about half throttle revs, one right after the other, allowing it to reach around 2500-3000 rpm. When the engine accelerates between revs and is under slight load (created by the half or higher throttle) you'll hear a knock.

If you can't get it to do it, most likely, you have an exhaust leak.

[Structure240sx]

boost creep could be from the cold weather

what are your afr's when the car is jerking above 5500rpms?

whats your spark plug gap? how old is your distributor cap and rotor?

[sunnys14]

What are you using for boost control?

Most likely your ticking is an exhaust leak. You can test for knock by doing the following:Sitting still idling out of gear, give the car about half throttle revs, one right after the other, allowing it to reach around 2500-3000 rpm. When the engine accelerates between revs and is under slight load (created by the half or higher throttle) you'll hear a knock.

If you can't get it to do it, most likely, you have an exhaust leak.

im using an 8psi spring and 38mm wastegate for boost control. it ticking gets faster and faster as i step on the gas but not louder... i hope its a exhaust leak.

[sunnys14]

boost creep could be from the cold weather

what are your afr's when the car is jerking above 5500rpms?

whats your spark plug gap? how old is your distributor cap and rotor?

my afrs are about 11.5s till i hit 5500rpms then it dips to about 9. my spark plug gap is about .035 and the cap and rotor are brand new. i didnt ground the orange wire off the z32 maf. its the 2nd ground wire that u can either ground to the chassis or any ground. i left it open... at idle, what voltages for my z32 maf is my SAFC2 supposed to be showing when i go into sensor check mode?

[sunnys14]

could it be that my plugs are so worn out because of the richness that its not giving enough spark?

[Tx-Sx-FS]

hey, its been said before...but since you went from FMU to SAFC..make sure you pin in/outs are the correct ones..and your gap looked a lil big...most people i see run low .030" or even .028" If im wrong correct me, also the other day my buddy ran his and his MAFS wire moved/touches the block and kinda shorts or something and keeps his motor from running higher rpms...and on the ticking thing, check oil level..sounds stupid but my SR20 blew when the oil was slightly low..let me know updates. later.

[Craving4Boost]

did you try leaning it out after 5500rpm? maybe its too rich. remember you need the most fuel at peak tq but after that it flows less air and your going to have to lean it out a little. 9 is very rich.

and i thought you had a smaller gap than .035? definatley check that out as well.

boost creeping till 10 and your still running good AFR's? whats the problem then . you wanted to run 10psi spring before. I know some people who ran 8psi spring nad get to 9-10 at high rpms. better than using a 10psi spring and creeping till 12 right?

[Florida240sx]

I got my gap at 31 and works pretty good. Back when my gap was 66 i had some problems.Guess those plugs had been in there since that car was made.

[KATwo40]

Ran my gap @ .44 for about 6 months...then turned up the boost to 10psi and I run .35 with no problems. And that's stock ignition, NGK plugs, NGK cap/rotor/wires (stock blue wires...nothin' fancy).

[nissanfanatic]

Problem is 9:1 AFRs.lol After 5k, you could lean it out to right around 12:1 with no problems...

Gap down to .030" as well...

You'll know when you have rod knock... Its very obvious...

[Jookmasta]

as said before, lower gap immediately on those spark plugs. yes lean it out also after 5500rpms as 9's are crazy rich. the boost creep could be due to cooler weather out on ur tuning nite. try those things and report back.

[sunnys14]

after listening to the ticking from my car, i came to a conclusion that my BD manifold is cracked at the bottom where the 4 runners connect! im going to take it off and bring it to my muffler shop and have them reweld it. as for the sputtering, i leaned it out after 5500rpms and its still the same. i pulled my plugs and i found out that they are gapped down to .032 (my brother gapped them for me when i wasnt looking =P ) and it still sputters... could this be a bad maf or another boost leak?

[Jookmasta]

lower the gap even more...............i run .25 or .28 i think so try that. also sorry to hear about the cracked mani.