Fuel pressure problem

[xxraptor660xx]

I'm having sputtering problems with my car, and running extremely rich. Here's what I noticed.

At idle, the fuel pressure sits at about 26psi.

When you push the throttle to 2.5k rpm, the pressure is at 45psi, and the car sputters and spits. Is this fuel pressure normal? What can be causing this?

Thanks for the help.

 

[blcknspo0ln]

Shlomi, do you have an AFPR? If so, pull your vacuum line off and verify that the base fuel pressure is 37.5 at idle. How are you verifying that you car is running rich? Are you logging fuel trims somehow?

 

[snowborder714]

According to his profile, he does have an Aeromotive AFPR with a 255lph fuel pump. I would also suggest setting your base fuel pressure (and I think it's 37, not 37.5 ). How do your plugs look (I would assume pretty black if you're running pig rich)? If they are, I'd change them out as well.

 

[xxraptor660xx]

Shlomi, do you have an AFPR? If so, pull your vacuum line off and verify that the base fuel pressure is 37.5 at idle. How are you verifying that you car is running rich? Are you logging fuel trims somehow?

I do have an AFPR. I removed the vacuum line, and it was sitting at 36ish psi (raised to 37.5).

As for how I know its running rich..I'm burning a ton of gas. I drove the car last week, and I wasted almost 1\4 tank of gas dropping someone off about 5 miles away.At idle the exhaust is releasing smoke (light), and as you push the throttle, the smoke thickens and gets worse. Also my narrowband gauge (i know...lightshow) is on the second to last green dot next to "rich." I don't use it to tune but it can't be that innacurate, atleast it gives me an approximate reading.

 

[xxraptor660xx]

According to his profile, he does have an Aeromotive AFPR with a 255lph fuel pump. I would also suggest setting your base fuel pressure (and I think it's 37, not 37.5 ). How do your plugs look (I would assume pretty black if you're running pig rich)? If they are, I'd change them out as well.

Changed them a week ago.

 

[turbosax2]

Have you done a boost leak test lately?

 

[snowborder714]

Boost leak test lately?

Edit: ^ beat me to it

 

[xxraptor660xx]

Yes, had 1 leak, but I fixed it. Also, when I'm driving, and I pass 2.5k rpm, the car runs quick, and stops sputtering, boosts fine, etc.

 

[turbosax2]

Are you using the correct spark plugs? Are they gapped properly? Are you recirculating your bov? Any more info you can give us?

 

[xxraptor660xx]

Are you using the correct spark plugs? Are they gapped properly? Are you recirculating your bov? Any more info you can give us?

Yes I have the correct plugs gapped to .032 (NGK 7E0R) or whatever, I have the right ones for sure. I am recirculating.

UPDATE: Well there it goes again, my S-AFC resets again, all by itself. HI and LO settings are both at 0 across he board...This is deffinitly my problem, right? I'm going to have alot of fun without a wideband or datalogger.

 

[turbosax2]

How much boost are you running?

 

[xxraptor660xx]

14.5 psi. (Wastegate spring pressure)

 

[turbosax2]

Maybe try the BPR6ES gapped at .028 and see if you have any luck with them. It may not change anything at all.

 

[xxraptor660xx]

Maybe try the BPR6ES gapped at .028 and see if you have any luck with them. It may not change anything at all.

I'll order them tomorrow, auto parts are closed today.

 

[xxraptor660xx]

Yes I have the correct plugs gapped to .032 (NGK 7E0R) or whatever, I have the right ones for sure. I am recirculating.

UPDATE: Well there it goes again, my S-AFC resets again, all by itself. HI and LO settings are both at 0 across he board...This is deffinitly my problem, right? I'm going to have alot of fun without a wideband or datalogger.

Did anyone catch that? ^^

 

[blcknspo0ln]

According to his profile, he does have an Aeromotive AFPR with a 255lph fuel pump. I would also suggest setting your base fuel pressure (and I think it's 37, not 37.5 ). How do your plugs look (I would assume pretty black if you're running pig rich)? If they are, I'd change them out as well.

Sorry, I'm not a 1G post whore, I'm a 2g post whore

Did anyone catch that? ^^

I'm silently punching you in the head . Remember those settings I told you to put on the SAFC? do it! If you're running zero across the board then heck yea you're running rich. Stop making all of these posts and read up on SAFC tuning! You have your solution in your lap, just learn how to use it. Oh and the common used NGK spark plug is the NGK BPR6ES (for your application) gapped at .028 (use a feeler gauge not a silly ramp gauge). The part number may be different depending on where you order, but cross reference should still be BPR6ES.

Oh, and i'm going to say this only because this was my mindset for over 2 years (2 years of only a crappy 2g logger and no wideband). Just because your car feels fast does not mean it is fast. When you go WOT about 2.5k and the car pulls nice and hard, it is not an indication that everything is peach keen and happy. I think you have a nice power plant going and would suggest a wideband as your next mod. Tuning to an 11:1 afr will be your biggest weapon in maximizing your setup. I went far too long thinking I was making good power, when in reality I wasn't.

i.e., my "street" tune which I thought was a corvette killing tune turned out to produce 208fwhp on a 50 trim @ 16 psi . After a wideband dyno tune, I increased to 260fwhp just by tuning my SAFC.

 

[snowborder714]

Sorry, I'm not a 1G post whore, I'm a 2g post whore

Haha, that would explain it

 

[xxraptor660xx]

Sorry, I'm not a 1G post whore, I'm a 2g post whore




I'm silently punching you in the head . Remember those settings I told you to put on the SAFC? do it! If you're running zero across the board then heck yea you're running rich. Stop making all of these posts and read up on SAFC tuning! You have your solution in your lap, just learn how to use it. Oh and the common used NGK spark plug is the NGK BPR6ES (for your application) gapped at .028 (use a feeler gauge not a silly ramp gauge). The part number may be different depending on where you order, but cross reference should still be BPR6ES.

Oh, and i'm going to say this only because this was my mindset for over 2 years (2 years of only a crappy 2g logger and no wideband). Just because your car feels fast does not mean it is fast. When you go WOT about 2.5k and the car pulls nice and hard, it is not an indication that everything is peach keen and happy. I think you have a nice power plant going and would suggest a wideband as your next mod. Tuning to an 11:1 afr will be your biggest weapon in maximizing your setup. I went far too long thinking I was making good power, when in reality I wasn't.

i.e., my "street" tune which I thought was a corvette killing tune turned out to produce 208fwhp on a 50 trim @ 16 psi . After a wideband dyno tune, I increased to 260fwhp just by tuning my SAFC.

Wideband is coming in the mail...sir