1G AFPR run over

[Kringle]

Probably a dumb issue or something easy to fix, but I'm at a lost right now.

Alright, before i pulled the motor to clean up the bay a bit i was working on tuning the car and a member mentioned that i had AFPR run over. So while the motor is out i wanted to address the issue. I have no clue what pump i have but i am pretty sure its not stock, came with the car. Trying to avoid extra work and cash that will come with snapping the bolts on the tank for the hanger if need be. Anyway, the previous owner has the fitting that converts the stock feed line to -6 an line and is utilizing the stock return. I guess my question is what would be a good course of action to fix FPR run over. My best guess is upgrade the return line to a larger size line maybe use the old supply line as a return? I have search for awhile (probably not looking for right answer) but can find anything, can someone please point me in the right direction?

Also as a side note, i have came to relize recently that i had my fuel pressure set to 43 instead of 37, would this cause the same symptoms as run over?

 

[91talonts1]

As long as your ecu is set for 43psi base fuel pressure you're good. Check the fuel tab in link.

You're saying you have an adjustable fuel pressure regulator? If so, see if you're able to adjust the pressure lower than the 43psi you have now. If you can get the pressure to go down then it's not being overrun. A quality AFPR and the stock return line should be able to handle quite a bit of pump.

 

[Kringle]

As long as your ecu is set for 43psi base fuel pressure you're good. Check the fuel tab in link.

You're saying you have an adjustable fuel pressure regulator? If so, see if you're able to adjust the pressure lower than the 43psi you have now. If you can get the pressure to go down then it's not being overrun. A quality AFPR and the stock return line should be able to handle quite a bit of pump.

Yes, i do have a AFPR and i put a new gauge on it. So i can just turn the pressure down to the 37psi then, that makes my life way easier. I was looking into using the old feed as a return line.

Wouldn't turning the pressure down at the regulator cause the over run to be more substantial? I can't recall the brand regulator it is, but everything else is fuel lab and AEM, well filter and rail anyway. Maybe the the regulator is just crap though, ill have to look. Going to be a month or so till i have the engine back in the car, life is getting in the way of my play time.

 

[91talonts1]

If there's enough adjustment to turn it down then it's not being overrun. Overrun means there's more fuel getting to the rail than the regulator can dump back to the tank. It's not possible to reduce the pressure when this is happening.

Your profile says you have link. If so you don't need to reduce your base pressure from 43psi. Just set base fuel pressure in the fuel tab accordingly.

 

[Kringle]

Yes i do have link.
Ok so let me see if I'm understanding what your saying correctly. Don't turn down the base fuel pressure at the regulator, instead turn it down in link on the fuel tab?

 

[91talonts1]

If you have the base pressure set to 43psi on the regulator, just set the base pressure in the fuel tab to 43psi. It doesn't matter what your base pressure is as long as the ECU knows what it is. If you turn it down to 37psi, same thing, make sure the fuel tab matches. Having the base set to 43psi vs 37psi will make your injectors flow a little more.

 

[Kringle]

Ok i got what your saying now, i thought you meant set the regulator to 43 and link to 37. I have both set to 43, and everything I've read say the stock return is fine for our cars. My guess is i either have a massive pump (not likely), a vacuum leak (tested to 25 psi that leaked down to 0 steadily over a minute), shit regulator, or return line to small.

 

[91talonts1]

What's the problem you're having?

 

[Kringle]

This is going to sound dumb i know, but a guy was helping tune the car and get my injectors dialed in for idle and mentioned that my logs look like i am having over run issues. Not sure how he knew or could tell from my log, but when i checked my regulator at idle he was right. I was idling at around 38psi, and i believe it should idle at 35psi at idle if my math is correct.

never got around to asking if a cam would throw off my vacuum at idle though. so it might be fine i don't know. I'm trying to fix issues while the motor is out and I'm waiting on parts

 

[91talonts1]

The pressure will vary with vaccum/boost and with temperature. Best way to set base FP is get the car up to operating temp then turn the engine off. Turn the fuel pump on in the misc tab and then set the pressure at the regulator.
38psi is around what I average with the car running @ temp with a 43psi base.

 

[Kringle]

Alright ill give that a try, i don't think i set the pressure with the engine at operating temp when i did it. Im waiting on my BEP housing and manifold to get back from the ceramic shop so i can install my H1C i picked up on the cheap the other weekend.

Ill post back and let you know whats up, but thanks for the help. Sorry i can't give instance feed back if its fixed, but like i said I'm trying to fix the little issues i had before i pulled the motor.