Ok, quick question. Messing around with new motor and I am setting the fuel pressure. You set it with the vacuum disconnected right? I am running 30 lbs svo's so I am gonna set it at 43 psi with no vacuum. Is this correct?

 

Depends what flow constant you put in the PCM. SVO's are flow rated at 39.2psi (no vacuum), but will work fine at 43.5psi (no vacuum), yielding about a 5% flow increase. But you need to tell the PCM what your flow constant is, based on the actual "no vacuum" operating pressure.

 

I have it entered in my pcm constant as 31.61. Any good or?

 

That is the correct conversion for running a 30# 2.7bar injector at 3.0bar.

 

So My settings should be fine? Reason I ask, It seems to be really rich when I start it. I have to put it to the floor to start it after I turn it off. I dont have a Datalog yet as I am still putting the finishing touches on it.

 

Does the pressure drop correctly when you attach the vacuum compensation line?

 

Yes it drops down to about I want to say about 28 lbs when the vacuum is on. I am not sure right now as I took the Y-pipe back off. I installed a 2 3/4 diam. y-pipe and having to modify a couple of things to make it fit.

 

When you attach the vacuum line, it should drop in proportion to vacuum. 5 to 8psi drop is normal... the higher value for a stock cam, the lower value for something hotter than stock.

 

Well I am running a hot cam with LT4 heads and intake ported and polished. I had MadZ28 do a tune on it before I added the heads and intake. Let me put the y-pipe back on and see what the fuel pressure is idling.

 

Ok I got it back in. I was wrong about the pressure. Its at 35 idling with the vacuum on. what do ya think? I think I am gonna have to get a running datalog in closed loop to better diagnose this thing. This thing sorta has a lumpy idle. It didnt have that before with the stock heads and intake. I also added the bigger y-pipe and high flow cat after getting the tune. I am pretty sure I am gonna have to switch some things in the computer.