Can't Break-in Built Engine

[MaxType 240]

Guys, I was trusting my searches to resolve this but couldn't find anything like this

Problem since mile 0 of the engine: under load, the engine will not accelerate past 3.5-4.0k RPM. Acts like a fuel cut off, it just falls flat. I can redline it in nuetral though.

Previous engine ran fine aside a cooling problem. Nothing has changed in terms of ignition/fuel/turbo goodies.

I met up w/ Enthalpy on Sat to upgrade my ECU ROM Tune from the beta version I was running. Still no resolution.

On the dyno, there were no signs of vacuum leaks or bad fuel pressure. A/F looked solid at WOT. MAF voltage was linear, no fluctuations.

Car idles fine, accelerates smooth as a kitten under partial or WOT until ~4k RPM.

Can I safely assume this is ignition related? Think a Nissan consult can pinpoint this?

So I've tried to put as much load on the engine as possible to seal the rings but fear I missed my chance - please help!

Jesse

PS - RPS 475tq clutch is super driveable, I love it!

[Import_Ant]

hmm... what did you gap your sparkplugs at? I'm leaning toward ignition too. what boost are you running? have you tried decreasing your boost?

[wild_maxx]

off topic, did you ever sell that SOHC block? if not i am interested.

[MaxType 240]

Ant, plugs are Iridium 7s at .28. I have an HKS ignition on there too.

Turning the AVC-R off didn't do anything either.

I asked about the Nissan consult tool b/c perhaps that could check my dizzy coil & CAS? I have an extra dizzy so I'll swap it out and see if that helps any.

Only occurs under load, I'm gonna start troubleshooting ignition to focus my efforts.

PS - SOHC block/crank is still for sale. In negotiations w/ 2 others, email me for further info.
Modified by MaxType 240 at 12:48 AM 5/26/2005

[Structure240sx]

try throwing in a different dizzy

[Jookmasta]

my car does that when i have it set at 1 bar for the wastegate. when the car reaches 4K, does it jerk or any weird sounds? also what are ur A/F's and how much boost were u runnning.......

[wild_maxx]

PS - SOHC block/crank is still for sale. In negotiations w/ 2 others, email me for further info.

Modified by MaxType 240 at 12:48 AM 5/26/2005[/QUOTE]

Emailed ya. my email address is [email protected]

[GEO]

Does it sputter?

[MaxType 240]

my car does that when i have it set at 1 bar for the wastegate. when the car reaches 4K, does it jerk or any weird sounds? also what are ur A/F's and how much boost were u runnning.......

Jook, it doesn't jerk/buck but it does "flutter" - trying to make power but just simply acts like a rev limiter or fuel cut.

It does make a weird sound I've never heard, a deep exhale of air when that happens. No high pitch sound of the GReddy TypeS.

I did add a 10lb spring in the WG over the 4lb spring I had. This situation happens if the boost controller is on or off. My vacuum lines are correct.

A/F is 12.1 at WOT. I've only been able to hit between .35-.60bar of boost and it's not cosistent.

I appreciate the help!

Jesse

[Structure240sx]

a flutter could be compressor surge

i think it was DaveEEE orion was helping with his surging problems while trying to boost. iirc its from hitting boost before the surge limit/compressor map. im no expert on maps or this. contact orion

[nissanfanatic]

What size turbo is it? Surge would be caused by running too much boost for the amount of air you are flowing. Its typically a problem with very large compressors on small engines.

[WDRacing]

Sounds like your IAT sensor is broken or the connection is bad. Check it out, we just had the same problem on my buddies hardbody pickup.

[wild_maxx]

still have the SOHC block for sale? if so i will take it if you can do 400.00

[WDRacing]

Quit cluttering up threads with off topic posts...you've been warned.

[MaxType 240]

Sounds like your IAT sensor is broken or the connection is bad. Check it out, we just had the same problem on my buddies hardbody pickup.

My IAT has been disconnected since 2003. I though IATs were just for OBD & that they did not affect engine performance.

Can I be running in some sort of safe mode? There are no codes on the ECU. I'm gonna find a Nissan dealer and plug into their consult.

[WDRacing]

Your ecu uses the IAT to determine whether or not to retard timing ot what map to use. Hot days require less timing advance.

[wild_maxx]

sorry WD for the off topic stuff. no more.

[D Money]

maybe maf or transmission harness? what rpm exactly does it stop?

[MaxType 240]

maybe maf or transmission harness? what rpm exactly does it stop?

It stops accelerating and dumps the air around 4k. I do mean dumps the air!

Everything looks smooth on the MAF, no volatility in voltage.

I installed the WG spring so fast, I don't know if there's a side that's supposed to be face up or what not? Didn't even read how to install it, just did it...

Jesse

[Jeff240sx]

I don't know if there's a side that's supposed to be face up or what not? Didn't even read how to install it, just did it...

Jesse

No. It's a spring. -Jeff

[xsblacksx]

sounds like you got in too deep

[scottsi]

suprised no one said boost leak, im betting money that is what it is. at 4k is begins to build boost, or it shoudl, but it isnt, and the engine is throwing tons of feul into it and not enoguh air is coming in because of a blown charge pipe or boost leak

[deviousKA]

Your most likely running to rich with to little timing, common stuff when tuning turbo cars, erroring to the side of safety.

Get your boost transistion>full boost tuned about half a point leaner, see if that helps. You dont need 12:1 for anything under 10psi, not if you want to make the power youd expect anyways.

And try bumping your timing a couple degrees as well.

edit: and yes half a point of a/f does make a huge difference with lower boost.

[Nismo_Freak]

That S14 is one of the cleanest I've seen, props on the excellent parts choice.

[fiznat]

*check the date on the thread before you reply, please!* I'm sure it your turbo advice isnt really helping the guy almost a year later! lol...

[Chezedik]

Here's a noob question... whats a dizzy coil?

[fiznat]

Ignition coil. It attaches to your distribuitor so I guess it qualifies as a "dizzy coil?"

[C-Kwik]

This thread is way old. I would hope the problem was solved by now. But if not, any engine codes? Mine had somewhat similar problems, but was a lower RPM. Turned out the ECU was in safemode for a wire that broke within the insulation for the coolant temp sensor. THe ECU can have many safemodes that come up. I'd pull engine codes to see if it says anything might be wrong.