fuel pump going or injectors?

[BAKA92]

from the log i think my fuel pump is going or i need bigger injectors. this was on 92 premium, 14psi ,2g mas, 550, b16 with mods(in profile). safc setting hi 1k +15, 2k 20, 3k-5 +25, 6k +20. 44psi fp. looks rich eh, but to get the o2s to cycle at idle i have 1k +26, thats to get the low trim to +/- 100% i looked at the plugs, there all white maybe a hint of brown. i have fic 650s and a walbro 255hp pump on the way, but i wanted to see if you guys had some input to share.

You must be logged in to view this image or video.

 

[Maverick3169]

I wouldn't think that you should be dumping that much fuel into her. Sometimes you could run so rich that it reads lean, you know?

 

[spyderturbo007]

Let me get this straight......You are running 550cc injectors and a 2g MAS while adding 25% fuel with the SAFC? WTF

Not a good idea. The 550's and 2g MAS should almost cancel each other out. Your SAFC settings should be around 0.

 

[donmagicjuan]

I'll agree that you shouldn't be adding anywhere close to that amount of fuel with 550s and a 2G MAS. Plus, you're running higher than stock fuel pressure! It sounds like you have a fuel volume issue. I would check the fuel system for leaks or kinks. If the problem occured right after your fuel system upgrades, I would double-check the fuel pump installation. An improperly installed pump can also result in a low-flow condition. Here's an example:

http://www.dsmtuners.com/forums/showpost.php?p=50472328&postcount=28

 

[BAKA92]

i'll take a look at the fuel system. the afc settings are that high to keep the fuel trims down around 100%.

 

[spyderturbo007]

safc setting hi 1k +15, 2k 20, 3k-5 +25, 6k +20. 44psi fp. looks rich eh,

I went on the quote above and assumed that you were setting the High Throttle table.

 

[high klicks]

Two things I noticed that I would change based of my experience with my own info that I have picked up lately. One lower you fuel pressure it should only be 37 psi for 1G at idle, second does it smell like gas at idle? If it does then you know you have to much fuel, if it doesn't you can adjust away but one thing I found it's a bi*** to get low trim to work right and since once you touch the gas your out of low trim I don't even worry about it, Just get mid and high working right without knock and don't worry about it. If you really want it to tune right the best thing you can do is get a wideband oxygen sensor, borrowed a friends for a quick tune and the car was a rocket, by far the best thing to do gives you way more info

 

[Kevin Jewer]

It shouldn't be 37 psi at "idle," but with the hose off. At idle, fuel pressure will be base pressure minus vacuum (divide inch/hg by 2 to get PSI).

Estimating airflow of course, you are targeting something around 8:1 in order to get 100% IDCs with those injectors, at that base pressure, on that fuel. Obviously something is up.

The main problem I see with the log is the timing, it's too high. And it's still the retarded 1g curve. Thank God for DSMlink. If this was my car, and I couldn't get timing corrected with DSMlink or similar, I would reduce base timing.

 

[BAKA92]

yeah the hi settings are same as the low setting. i have the stock fuel pump and it still has the plastic retainer thing on the base, which makes me think that the guy who did the install didnt put it on. 100%dc, is that what happens when you run high fp and +26 correction? my airflow on the afc was about 2250 -2300hz at 6000k. my injectors and pump were both used items when i had them installed, the guy i got them off of raced his car alot so i dont know excataly how old or shape they were in. i would race my car more if my tuning didnt suck.

 

[donmagicjuan]

Is that airflow MAS IN frequency to the AFC or MAS OUT to the ECU? Granted, it depends slightly on the weather, but if you're seeing 2300 Hz at 14 psi on a big 16G, I would think you have a boost leak somewhere. I get about the same numbers for airflow running 25-26 psi on my EvoIII 16G. If you do have a leak, the turbo is probably blowing some really hot air, which would explain the need to drown it in fuel to get rid of the knock.

IDC is determined by the ratio of injector open time (pulse width) over available time (function of RPM). Changing fuel pressure won't affect the IDCs unless you alter the tune to compensate for the different pressure.

 

[BAKA92]

i have my afc hooked up the way the vfaq has it. i was thinking the hz numbers was alittle high too. i think the temp was around 82-85 deg. by the way what are about normal intake temps for mid 80 deg weather, cause i remember i logged them once, it was in the 120s-150s if i remmber correctly it was awhile ago.