S13 redtop running rich

[Sr20probs]

Hey my sr red top is running rough/breaking up. It will idle okay can?t tell how smooth due to open down pipe but seems smooth and holds rpms. The fpr needle seems to be going crazy between 40-42 psi gauge (aeromotive) but I can?t tell if that?s just from the solid motor mounts vibration. It?s also smoking out of the catch can filter. The bottom end and head was assembled by a professional machine shop so that should be able to be ruled out. It?s running a megasquirt pnp2. I burned my injector size 740cc . Circuit sports fuel rail. I could use some help. Thanks
Mods
272 bc cams along with valves, springs, and retainers
Isr front mount intercooler
Hks BOV
forged bottom end of that matters lol
Gt2871r turbo too mount manifold
10 micron fuel filter

[dorkidori_s13]

when was the last time you changed your spark plugs?

aaaaaaand youre running a stock fuel pump with this setup?!

[Mikester]

Is it idling fine but breaking up in boost? If so, have you tested for boost leaks?

Fuel pressure needle erratic or not, have you confirmed it is running rich with a wideband? Even with an OEM regulator, do you have enough fuel pump to support a rich condition?

Glad you had it professionally built. Was it professionally tuned too? I am not familiar with Megasquirt.

Circuit Sports fuel rails are nice for the money. When you replaced the rail, did you replace the injector seals where the rail connects to the intake manifold? I have experienced boost leaks there prior to replacing the seals.

To me, a rich condition and breaking up under boost is not a fuel problem, but more likely to be an air (boost) leak or fouled plug(s).

The 'smoke' you see coming out of the catch can filter is likely a separate issue. Could just be hot oil vapor escaping since you have a filter and do not have it routed back to your turbine inlet pipe. You might consider putting negative pressure on the crank case. There are good threads here on how to properly route catch can plumbing.

As for you main issue, more info would be helpful.

Mike

[Sr20probs]

I have new seals for the injectors yes, it will boost if I floor it and idle just breaks up at a certain rpm. This is all without load (not driving) I have the mazworx plug to seal where the breather pipe to the factory t fitting in the valve cover and was then routed to factory intake. I then routed the catch can to where the t fitting was and where the PCV was. Let me know if you have a better idea. I wasn’t thinking and just bought a walboro 255 it’s currently stock.

[Kingtal0n]

Oh my god

0. You need a wideband
1. The engine needs to be tuned
2. The engine needs maintenance items up to date (plugs, clean oil, pcv valve etc...)
3. You must pressure test the entire system before tuning or running boost
4. dont use solid motor mounts generally
5. The engine should have a full factory PCV system *NOT a catch can*

I mean... smh

[Mikester]

Originally Posted by Sr20probs

I have the mazworx plug to seal where the breather pipe to the factory t fitting in the valve cover and was then routed to factory intake. I then routed the catch can to where the t fitting was and where the PCV was. Let me know if you have a better idea.

Don?t know that this is THE issue, but it sounds like you have eliminated PCV (positive crankcase ventilation) altogether. In a proper SR20 ventilation system, the PCV valve opens in vacuum & provides negative pressure to the crankcase. Then in boost, the PCV valve closes and the suction from the turbo provides the ventilation. The only way a catch can on the PCV side would make even a little sense is if it was between the PCV valve and the intake manifold. You really shouldn?t take it out of the equation. PCV is important.

As for your main issue. Put the Walbro in and get it tuned. I assume a Megasquirt doesn?t come preset for a 2871 & 740cc injectors(?)