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High oil and fuel pressure after start up

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
Hey everyone, This is a 6 bolt block with a 2G head. Upon first start up, trying to break then engine in by reving it high up around 3k on the tachometer. But I shut off imediatley after I noticed that my oil pressure was around 60PSI and fuel pressure at a whopping 80psi :O


For the oil pressure, I guess it's because of my balance shaft delete? I never ported the oil filter housing as I didn't want to mess up, or incase my oil pressure was already low. Should doing this common fix lower the pressure where I need it? I just don't feel like it should be 60psi without the oil even really getting warm.

For the fuel pressure, well alot of work's been done with the fuel but really not so much different from factory. I'm not %110 sure that I have the factory pump, but it's been replaced and is a walboro, didn't see any numbers. The fuel pump has been rewired / fused with 10 guage wire. Entire new -6an lines from the pump, to fuel lab filter, to stock 2G fuel rail. The fuel rail has a relatively new stock fuel pressure regulator, and for the fuel leak test, it seemed like you could hear the fuel make it to the rail and go around.
Stock fuel injectors also. Haven't done any tuning really.

I've always read that the stock pressure regulator shouldn't get overrun until you upgrade your pump? Even with the rewire since it's a fix not an upgrade. But I guess I have no choice right? I should really get a good AFPR?
 

eclipsemf

Proven Member
398
4
Jun 10, 2010
Glen, New_Hampshire
That oil pressure seems fine for a 3k rev on a cold motor. The pressure will only go down once the oil gets hot, not up like you stated. Your oil pressure really shouldn't go over 100psi if it does I would defiantly look in to the OFH port mod. When you did the BS delete did you make sure you put the bearings back in correct so they blocked off the right oil holes?

Your stock FPR can hold a 190lph fuel pump comfortably but some have trouble when they get to the 255lph range so if you do happen to have an upgraded fuel pump that is bigger than a 190lph that could be your fuel pressure issue.
 

Roberti 2G

Proven Member
363
17
Mar 5, 2012
Holloman AFB, New_Mexico
I believe that is normal oil pressure for cold start up..or I should say not uncommon.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
Okay so it sounds like my oil pressure is probably good then, good to know.

Is the AFPR the only way to mess with the fuel pressure?
 

thearkatek

Proven Member
153
1
Jul 29, 2012
Saint John, NB_Canada
Its the only way for YOU to mess with the fuel pressure, but that doesnt mean your fuel pressure isn't messed ;)
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
Its the only way for YOU to mess with the fuel pressure, but that doesnt mean your fuel pressure isn't messed ;)

what's the highest my fuel pressure should be? for Afprs, screwing the screw outwards should lower the pressure, while screwing in would increase pressure correct?
 

boost97gst

Proven Member
3,035
130
Apr 2, 2012
st jacob, Illinois
Your pressure with no vac on the afpr should be about 43psi.
 

ramsack

Proven Member
3,286
16
Dec 27, 2007
West Lawn, Pennsylvania
At -20 inHg your fuel pressure should be ~35 psi, at 0 inHg, or 0 psi, it should be 43.5 psi, and with boost, it should rise 1 psi per 1 psi of boost. It's likely an overrun regulator.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
I understand the fuel pressures normally around 34-44 psi. Mines just before 80 Psi.

still pretty sure it's a stock walboro but could be a 255.

Just read about switching to a bigger return line, like 3/8". If that doesn't help enough then I'll have to buy an AFPR.

what is inHg?
 

ramsack

Proven Member
3,286
16
Dec 27, 2007
West Lawn, Pennsylvania
There's no such thing as a stock Walbro. Try different gauges to measure the fuel pressure, too. You could test if it's the return line by just hooking the return off the FPR to a long piece of thick enough hose and let it run into a gas can while looking at the fuel pressure. That will test if there's a restriction in your return line.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
So walboro is definitely not stock for 2gs? I swore walboros also came from the factory.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
Definitely not. Evo's came with a walbro 190 equivalent

thanks for the clarification. That must be where I'm confused. I assumed I have a 190 and that was factory. could a 190 overrun the factory regulator?
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
No a 190 walbro can not overrun an afr. Not even rewired can it do so.

I meant can it over run the stock / factory regulator. the 190 pump.

and for the oil pressure, what should I expect the pressure to go down to once i.rev it around 3-4K and the oil gets warm? If the oil was at 60psi last time.
 

eclipsemf

Proven Member
398
4
Jun 10, 2010
Glen, New_Hampshire
I meant can it over run the stock / factory regulator. the 190 pump.

and for the oil pressure, what should I expect the pressure to go down to once i.rev it around 3-4K and the oil gets warm? If the oil was at 60psi last time.


No, As I sated in my original post a 190lph fuel pump will not over run the factory FPR unless it is bad prior to the install of this new fuel pump.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
thanks to everyone as usual.

My main question is, if my oil pressure stays at 60psi or even goes higher, . should I shut off?
 

ramsack

Proven Member
3,286
16
Dec 27, 2007
West Lawn, Pennsylvania
If it's cold, don't worry about high pressure during that time. In the manual it states that the stock oil filter is designed to hold 256 psi in the case of high pressure cold oil. The oil pressure is so high when it is cold because the pressure is measured before there are any real restrictions, and after the filter housing the thick cold oil has to squeeze through small galleys and bearings.
 

1Gina2G

Proven Member
811
2
May 6, 2011
Beaufort, South_Carolina
If it's cold, don't worry about high pressure during that time. In the manual it states that the stock oil filter is designed to hold 256 psi in the case of high pressure cold oil. The oil pressure is so high when it is cold because the pressure is measured before there are any real restrictions, and after the filter housing the thick cold oil has to squeeze through small galleys and bearings.

I appreciate the explanation. So as long as my oil pressures not maxed out I should be good once the oils warmed up? as in below 80 psi.

what about fuel pressure? is 60 as high as it should ever be?
 

ramsack

Proven Member
3,286
16
Dec 27, 2007
West Lawn, Pennsylvania
I explained the fuel pressure thing earlier. It needs to be exact. Oil pressure, no. It is just a something to monitor. Don't rely on one gauge. Electricians don't rely on the reading of one multimeter.
 

eclipsemf

Proven Member
398
4
Jun 10, 2010
Glen, New_Hampshire
I appreciate the explanation. So as long as my oil pressures not maxed out I should be good once the oils warmed up? as in below 80 psi.

what about fuel pressure? is 60 as high as it should ever be?


:banghead:

Go back and read what we have told you! Oil pressure over 100Psi when warm should should start to be a concern it some times will come close when boosting. Fuel pressure should be a 43.5 at 0Hg on stock boost, and increased to the like of 1psi per 1 psi of boost increase as ramsacl nicely put.
 

ramsack

Proven Member
3,286
16
Dec 27, 2007
West Lawn, Pennsylvania
Oil pressure over 100Psi when warm should should start to be a concern it some times will come close when boosting.

Boost has nothing to do with oil pressure, only engine speed and temperature of the oil.
 
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