Diagnostic help S13 SR20

[jscherf92]

I need some help diagnosing what could need addressing with my recent swap. Stock SR blacktop, T25 turbo, FMIC, stock fpr, stock ecu.

Issues:
-Car bucks under acceleration, 50% throttle boost surge, NOT a transmission issue.
-Hesitation under light acceleration, when you first depress the gas pedal the car hesitates at first and then accelerates normally.
-Boost leak? under acceleration in 4th and 5th gear, boost built to about 5 lbs, lost it and quickly caught up and built boost again.
-Fuel pressure rises to ~50psi with light acceleration, when put under a constant load the fuel pressure drops to idle levels.

Let me know what other information I can provide and what tests I can perform to help diagnose these issues. I've got time to work on it all next week so please please please help me out. Thanks

I've got a short list so far, Ill be cleaning the IVAC, MAF, checking the TPS, no visible boost leaks and vacuum lines are run directly to FPR, Boost/vac gauge, and BOV

[Mikester]

Did you connect the speed sensor? The alternator charge signal goes thru that connector as well... If not connected, the fuel pump will not put out enough fuel in the upper rpm ranges. Put a meter across your battery at idle- should be charging at 14.2-14.5V... If it's charging at 15 or more, this tells me that connection isn't there.

Could also be a boost leak; but usually wouldn't stumble then go back into boost. Sounds more like fuel is cutting out. Make sure that connector is connected... and get a 300ZX or Walbro 190/255 fuel pump...

Also, if you used any kind of octane booster or fuel additive, this is a problem too- that shit cooks SR/RB plugs... If you did this, run it as low on fuel as possible, fill it back up, change the plugs & never do it again.

[jscherf92]

Ill double check on the sensor and report back with a voltage reading. I've got my fsm handy so if nothing else Ill trace the wires and see what's going on with that. It seemed to run a little smoother today than it has been but still some little issues here and there. Thanks!

[s13mikesr20]

whats you vacuum lines look like deliver some pics then I got you a answer

[jscherf92]

Three on the throttle body are run directly to a boost/vac gauge, fpr, and BOV. Then the other side has the stock boost pressure solenoid hooked up to the intake pipe, hotpipe, and wastegate according to the fsm. I cant see any places where there would be a leak, no cuts in the lines, no bad clamps. Keep suggestions coming, ill have some time to check things out tomorrow afternoon and then again on monday. Thanks guys.

[ultimateirving]

Do a boost leak test. That's what my money is on. Also coil be a bad coil pack

[mr.nismo.]

Boost leak test. All your issues seem to be connected by vacuum

[jscherf92]

Safe to assume I can rig up something like this?

Pro-Kit NISSANSR20DET T25 Turbo by turboboostleaktesters.com (http://www.turboboostleaktesters.com/servlet/the-100/Pro-dsh-Kit-cln--NISSAN-cln-SR20DET-T25-Turbo/Detail)

Obviously I'm not spending $30 on a PVC cap, valve stem, pressure gauge and a coupler but as I've never done a boost leak test would that be the tool to use?

[xinlisuzhi]

If you did this, run it as low on fuel as possible, fill it back up, change the plugs & never do it again.http://to.ly/pUrL
:bs: