So i tried searching and the results i got seem to be mostly issues of people running rich at idle or "think" they are running rich sole by smell and no AFR. unless im not searching the right terms......

So lets ASSUME its not the tune (base map). My mechanic usually leaves the base map tune a little rich to be on the safe side but it shouldnt be this rich and he said i should start diagnosing it.

Symptoms
At idle its roughly 11.x and occasionally sees 12.x
light throttle, WOT, anything besides idle its in roughly 10.5. cruising i MIGHT see 11.0
Injector duty, i havent really been monitoring this but these are ball park numbers
-idle ~15
-cruising ~25?
-neutral rolling ~15
-in gear rolling ~ 15
~8-10mpg.....................

Mods: not this is rebuild HBP motor with 115 miles currently.
ALL emissions delete
-double butterfly removed
-back of the TB where the thing is spring loaded? mine is tied back (completely forgot what this is called)
ported UIM, LIM and shaved emissions
550/1600 on stock/KG rails
aeromotive FPR (~42-43psi base and around 38-40 psi with vacuum)
Denso "supra" fuel pump
fuel pump resistor delete
fuel pump relay mod
fuel Pulsation Damper delete

Fuel set up
Feed line> Primary rail (850)> Secondary (kg parts 1600)> Fuel pressure gauge (inline)> FPR > return line

Diagnose/test
1-IIRC, when im in gear, no throttle and rolling, my injector duty should be at 0. is that correct? if so im assuming its a injector stuck open. how do i check for this?Now if its stuck open, what does that actually mean? would the injector duty still be able to change? and will simply cleaning them fix this? Although possible, I HIGHLY doubt its a wiring issue as the harness was redone last year and never had problems.

2- Possibly a leaky injector? im ASSUMING its a leaky injector, meaning the mist pattern is dripping? fuel instead of spraying a mist? ill be pulling the fuel rails and putting them in a bucket and then ground the fuel pump. this however will check if they are leaking from the rails? how do i test the spray pattern?

3-other possible options?

 

What standalone are you using? PFC? Other?

 

I had this issue once and it was the injectors stuck open

I searched a lot and unfortunately I couldn't find any real tests for an open injector. The only tests you can do is to make sure they click on and off when powered, and you can also test the resistance between the 2 terminals on each injector.

Mine were up to spec, but I replaced them anyway and the problem went away. So I don't think there's really anything you can do besides just replacing them and see if that works.

The only other thing if that's not the issue, is that you're getting some sort of short on the wire harness to the injectors which is powering them open when they shouldn't be.

 

PFC
Yeah, that seems like worst case scenario. im against botching up my harness as i did early and just undid my wires tto redo em again. i highly doubt thats a problem since they are loomed and wrapped so its pretty hard for anything to expose the wires

 

Take a stethiscope and listen for them clicking.

I probably butchered that word.

Assuming the basemap is spot on with the injector scaling and your fuel pressure is set correctly to what the computer wants it to be at for the injector pulse width.

 

With the car, your fuel pressure must stay at what it is ajusted (38-43psi). If it not hold pressure you have a leak or a leaky injector

 

im going to have to buy one.. thats like the 100th time someone told me to use it to diagnose something...

does that mean if i rev or give it throttle the fuel pressure should stay the same? and if it drops that means i have a leak?

 

What are your running fpr a map sensor and what are the settings? If you pressurize the fuel system witht he car off by jumping the pins in the diagnostic connector, how long does the pressure hold when you unjump it? When is the last time the injectors were tested? If not how old are they? Check the orings themselves as they can leak too which will show up in the fuel pressure test.

 

I did a little error on previous post! With the car OFF, your fuel pressure must stay at what is set. If it drop slowly, you have a fuel leak or a leaky injector

Good luck!

 

im not quiet sure i understand... im running an aeromotive FPR and a gm 3bar map sensor. By the car off do you mean with the car in the "on" position? if so with the car in the on position, jumping the fuel pump the gauge reads 40psi, and i did it for 15 seconds and no drop off.

injectors never been tested, they were bought about 2 years ago and seen maybe 8k miles? a few of the orings have been replaced before i installed this motor

like wise, with the car on on position jumping the fp, its a steady 40psi for the 15 or so seconds i tested, is that long enough?

Also with the car ON, and RUNNING, the base psi is set at ~41.75psi, with vacuum its about ~36 when i rev it hits ~40, dips down to ~34 and then goes back to about ~36

The car idles at a steady 11.8-12AFR occasionally dipping to 11.6 for a milli second. Those AFRs at idle sound pretty good to me (base map) so theoretically, if my injectors were leaking, wouldnt my idle be super rich as well?

 

When you installed the gm 3 bar, did you change the scale and offset numbers with a datalogit?

 

If you're running 850cc primaries you'll probably always have a rich idle, they're a bitch to get a lean idle with. Cruising should be OK.

I assume the PFC is set up for the bigger secondaries?

Dale

 

Yes i have

idk why i wrote that in my first post, however, the primaries are stock 550's
PFC set up correctly 550/1600

My biggest concern right now is, when im driving and in gear, no throttle, my injector duty is reading ~15% when it should b 0%... i can only assume its stuck open? or..?

Also i forgot to mention im having break up but im assuming that due to too much fuel and when i start the car i have to blip the throttle (which seems like to me, theres too much fuel and i have to clear it out by taping the gas)

lastly i lowered the fuel pressure 5psi to see if that changed anything and my afrs improved to:
11.9-12.0 at idle
~11.5 when revving

Ill be taking it out for a quick drive to see if i notice anything else. im assuming this means my tune is just too rich? (but doesnt explain my biggest concern where injector duty is 15% when no throttle is given..)

ps what pim volt should i be at? normal or option 1,2,3,4?

 

Are you using an aeromotive FPR? Some of them are known to bleed fuel pressure KOEO, like when you first prime the system. The only reason I bring this up is because I don't want you to think something is wrong with your FPR when there really isn't. I run an aeromotive after the fuel rail in my neon and it won't hold pressure once the engine is off to save it's live. A leaky injector isn't the only thing that will cause pressure loss. Most fuel pumps have a built in check valve which prevents fuel from draining back into the tank through the pump. If that is on it's way out then you will lose pressure as well. It very well could be an injector stuck open though because you are running rich. Listen for the clicking of the armature in the injector pulsing up and down as the coils are energized. If you don't hear a click in one of the injectors, then it's probably stuck.

Are you able to look at your short term fuel trims at all?

 

i have fresh cleaned 550s if you want them, that i'm never gonna use

 

yes aeromotive fpr. what KOEO? i actually didnt think the FPR was one of the problems. once the engine and car is off shouldnt it lose fuel pressure slowly?

how do i check for clicking injectors? with the grounding the fp be enough? If i have to have the car running that would be impossible with the HBP and 4"... i cant even hear myself....

no idea what you mean by look at shor term fuel trims lol. i have commander if that helps?

how much and where in nj are located? who cleaned them/do u have paper work for it?

 

KOEO=key on engine off, and you need the stethiscope to listen for the injectors.

 

im an at home wanna be mechanic! no stethiscope =(

 

So heres something interesting.. today i just installed my gauges...

My stri fuel pressure gauge is reading ~47 and my jegs gauge on the FPR is reading 31... which one do i believe? the Stri FP gauge is in a summit t fitting right before the FPR. its in a 3/8 fuel line while all the other fuel lines are 5/16


but i still dont know why my injector duty is 15% while im not on the throttle.... is that a tuning issue?

 

What are your fuel cut settings?

 

I have a stand alone, so it may be different than yours, but I have several fuel cut settings. I used to have it cut fuel when not on the throttle, like you are trying to do. But since I premix, and don't have an OMP, I turned that function off, so now I have slight injector duty even when not on the throttle (to keep oil going through the engine).

Why are you idling so rich though? Those AFR's aren't right, unless a bridgeport just needs to idle that rich. I've got a street port and idle between 14 and 15, not 11 and 12 like you. Thats too rich for idle in most cars (my turbo G35 idles dead steady at 15 as well). Maybe just taking fuel out across the board will help you. As long as you aren't boosting it, being a little lean won't hurt it. Then once you are done breaking it in, the real tune seems like it'll straighten everything out.

 

no clue on fuel cut settings. idk 12.5 is normal for hbp (i think i cant remember its been so long lol)

 

Sounds like you need to adjust your TPS

If you had an injector stuck open it should be 100% ... only if the PFC was able to tell that the injector is stuck ^^
So if your injector is leaky or open, the PFC don't care and should say 0% as it cuts fuel (assuming your settings are not messed up).