Ok about 3 weeks ago i got back and tried starting my car after a replacing pistons rods and overboring. The car sat for over 9 months prior to that. Now that everythings in place, she is runnig SO SO rich. Its like she just dumps fuel in constantly. Its so bad i went through 3 sets of NGK's in about a 5 hour period. We thought it might have been the sensors b/c we yanked 4 off the motor and there was no change in the pig rich idle. I sent it away to be checked. The wiring, sensors and ecu are fine. The we thought that the combo of fuel pump, FMU, and 30lb injectors might just be too much. So we put on the S-AFC2 that i had purchased and we bottomed that out and still not even a little difference. But since its a fuel issue theres only 3 things it can deal with. Injectors, FMU, and fuel pump and tank. Yesterday i bypassed the FMU..no difference, but she did run good a little after i put the new gas in. Today we're dropping the tank and fuel pump, cleaning out the tank(maybe sugar in the gas tank but i doubt it) or the fuel pump is bad(what i personally think) and its just pumping with no regard to God or man. Has anyone had or know of this problem, let me know, im at my wits end with this thing. I love my car but for some reason she really wants to hate me.

Just to eliminate one of the things that you think could be broken... How much the fuel pump flows doesn't affect how lean or rich the car runs - the more the fuel pump flows the more fuel goes back to the tank through the return line. The pressure of the fuel in the rail stays the same, that's the regulator's job.

If its running that rich, check the fuel trims with a logger. See what the ECU thinks is going on. if the trims are pegged negative, start lowering the fuel pressure until it gets around zero.

i wish mine were anywhere close to zero...
doug

could it be the injectors? We've been talking and we're just going to swap for stock injectors and tune from there on the dyno, break the motor in on 7psi and after that tune for the bigger injectors......thats IF its the injectors. I'll hopefull find out today.

I think its either the the injectors or the FMU. The injetors are alot bigger than stock, and with stock pressures they'd dump a bunch of fuel in. Though you should have been able to turn them down a bit with the AFC. Sometimes the fuel pressure gets all whacky when people install FMU or SFMUs. Can you check the fuel pressure? Put a gauge on it and make sure you're around 43 at idle.


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Shouldn’t it be around 25 psi for 30lb injectors?
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the fmu is bypassed now and it still dumps fuel.

Explain exctly how you've plumbed your fuel system. there's something simple here that is wrong but we don't have enough info to tell you exactly what it is.

called some hrc techs and we believe its the ECU now(they're 95% sure). Bought one today...blind..so i feel pretty stupid about it b/c i dont even know if it'll fix the problem. I bought it for 150 so that wasnt bad, but I'll kick myself if it doesnt work. Its coming in tomorrow so we'll see whats going on then.

Sounds to me like something is messed with the fuel system...

Sounds like you've got way too much fuel pressure.
Like Dino said, how is the fuel system connected up?

its was just the basic fuel pump from the star kit, the fmu from the star kit, stock everything else except for the 30lb injectors. Running pig rich we figured it was the fmu so we bypassed it. Same problem. Now its either the injectors or ecu. The ecu is coming today and i have 4 injectors waiting for me if by some chance it doesnt fix the problem. Everyone out here is racking their brain b/c they too say its just something so simple that we keep overlooking it. This is my 3rd ecu! im still pretty bitter about that. I might as well change ecu's everytime i change my oil. But i got it back from this auto electric place (something else i did to get rid of the problem)and they said there were some loose connections so maybe that attributed to the ecu's going bad. Hell, Ill be making more power from this thing that i thought just trying to fix this problem. After the break in, how much boost do you think i can run on forged internals, bored .20 over, t3/t4 from star, 30lb injectors, profec b spec II, a fmic that can support 1200hp, and a safc2. I was thinking somewhere around 15-16 with tuning the safc on a dyno.

we replaced the ecu and the car is still running rich on 2 injectors and the safc cant control the duty cycle. It got rid of the CEL and is idling better..not good or excellent, but better. Were swapping out the injectors with stock ones tomorrow. Now please someone tell me with logic why is it the injectors. Ive had these 30lb for about a year when she was running but she wasnt intercooled. The way it was explained to me was that since it wasnt intercooled that it needed that fuel and now that it is it needs less fuel for combustion its just pouring fuel in. Thats was somebodys ligic. Please someone tell me the actual answer and why the injectors would be bad. AND why my safc cant control the fuel at all. PLEASE PLEASE PLEASE! Im gonna wrap it around a pole if this thing wont work(only half kidding)

It sounds like your running stock fuel pressures with 30# injectors. I'm not familiar with the star FMU but can you adjust the idle fuel pressure? You have to turn it down to run larger then stock injectors (unless you have a MS).

yes i believe it would be stock fuel pressure at idle. but now why is it a problem? Ive done it for a while.

Originally posted by Ruben Lopez
we replaced the ecu and the car is still running rich on 2 injectors and the safc cant control the duty cycle. It got rid of the CEL and is idling better..not good or excellent, but better. Were swapping out the injectors with stock ones tomorrow. Now please someone tell me with logic why is it the injectors. Ive had these 30lb for about a year when she was running but she wasnt intercooled. The way it was explained to me was that since it wasnt intercooled that it needed that fuel and now that it is it needs less fuel for combustion its just pouring fuel in. Thats was somebodys ligic. Please someone tell me the actual answer and why the injectors would be bad. AND why my safc cant control the fuel at all. PLEASE PLEASE PLEASE! Im gonna wrap it around a pole if this thing wont work(only half kidding)

Until you actually listen to what we are saying you might as well go wrap it around a pole. You haven't listened to anything and just started randomly taking things out and bypassing this and that. Logically, it's not the injectors. Especially if you had them on the car before you did whatever you did this last time. If you didn't realize that by now it's still not going to run right when you put the stock injectors back in. Who ever told you ...

Originally posted by Ruben Lopez
The way it was explained to me was that since it wasnt intercooled that it needed that fuel and now that it is it needs less fuel for combustion its just pouring fuel in. Thats was somebodys ligic.

... is a moron. Don't listen to him anymore! Ugh ... anyway, if this is setup like a typical Star kit fuel system there can be only a few things causing this. But first you need to gather your information (which you haven't even bothered to try). Answer these questions first.

1. What is your fuel pressure at idle?
2. What is your STFT and LTFT displayed on a datalogger at idle?
3. Are there any CEL or codes display?

As for your AFC. Since you haven't tried to hook up a datalogger you don't know what the AFC is doing. Try to check if the fuel trims change any? Oh and by the way ... the AFC doesn't control duty cycle. Your ECU does. AFC modifies the air flow meter signal(in our case the MAP sensor) to trick the ECU into seeing more or less air. The ECU adjusts the pulse width according to the modified signal. You're going about trying to figure out your problem the wrong way which is why you still don't have an idea of what is wrong.

Is this harsh? Yes. But you haven't responded to the kind suggestions anyone else made so maybe this will actually make you try to do some serious troubleshooting instead of hacking at it randomly.

Stock fuel pressure with #30's will for sure be way rich(im surprised it idles at all). Ditch the FMU and the safc and get a SFMU (and for gods sake get a freaking fuel pressure gauge). Im running about 12 psi(boost) now with the largest disk, hard spring combo, as well as the bleed screw all the way out, it is still a bit rich but runs great on #30 from accell injectors. FYI my idle pressure is about 20-22 psi.
If you don't want to do all that then put the stockers back in and don't boost over 7 psi. I would also still recomend ditching the afc. It can do wierd things to your timing durring boost, which can lead to a blown motor. Believe me I know.

the reason it seems like hacking at it randomly is b/c i have no direct control over what happens to the car. I sit at my house b/c i have no ride to the shop, I just got back from iraq and am trying to enjoy my leave but when the car is at the shop its kinda hard. This is really the first time my car has given me problems. Im friends with 3 different shop guys and they all put their heads together to try and figure out what the hell is going on. I go over there sometimes b/c theyre swamped and i had to do the FMU bypass and do all the odd and ends shit which i almost hate doing b/c thats what im paying them for, but then i actually like it b/c it is MY car. But thats a different subject. I almost got pissed at what you said until i realized that im sitting at a computer and you really have no idea whats going on or the situation. If i were in your position and read what i read and thats all i knew then i guess i might've said the same thing, but its more comlicated than that. And i do take all the advice very seriously. I do nothing all day so when i get a reply i call the shop real quick and tell them what ideas you have. So its not like youre advice falls on deaf ears. Its just my hands are tied when it comes to getting that information to the car. I do appretiate the help, but i dont appreciate the jumping down my throat in the un-informed and un-friendly manner. Im still fairly new to this site and and i dont go on the internet much but i can tell thats not a good way to make friends. So how about we start over and i just take your advice and relay it to the shop like i usually do and ill say "hi and thank you".

im not a mechanic nor do i claim to be, but when the knowledgable mechanics are having a hard time figuring out what is wrong with my vehicle and its keeping me from going home, you're damn right im gonna try and help whatever way i can. If that means trying to find out whats wrong with my car by asking questions and tellig you wat the shop is doin, then getting a "harsh" talking to by someone i dont know because of it, then so be it.

just got that call that the car is being wrapped up and almost ready to go. It turns out that it was the ECU. I appreciate all the help and advice that ive gotten from you guys, even though some of it was induced in an other than pleasurable manner(lol). You guys have made me want to know more about my car(technically) so im sure i will be on this site and ask for your knowledge again so i might be able to handle these kind of problems on my own and help others. Im not a dumb ricer, im just a driver. i know quite a bit but this tuning thing is a science. And i admire all you guys out there that use your knowlege and help others. I appretiate it.

Cool, I didn't want to come off like an ass (though I tend to sometimes) but there just isn't enough information gathered to reliably troubleshoot your issue. As I understand your situation here are the possible complications ...

1. There is no datalogger so you/shop doesn't know exactly what the car is doing in terms of fuel trim.
2. You/shop does not know what the idle fuel pressure is.
3. We don't know how the AFC was wired in and setup (you can't set it up like a 4g63 eclipse)
4. We don't know your exact fuel setup (unless it is just a stock star setup)

Without these pieces of information you can't effectively troubleshoot the issue. It's fine and dandy to go replace the ECU but unless you know what the ECU is doing in the first place it's not going to help you any. The ECU calculates how much fuel to put in based on multiple sensor inputs. Now it could easily be a sensor throwing things off but you don't know.

Once you turbocharge the car you should have AT A MINIMUM the following pieces of equipment to tune and troubleshoot issues/problems.
1. Boost Gauge
2. EGT Gauge
3. Fuel Pressure Gauge
4. Datalogger
If you don't have them ... get them.

Tell your shop they NEED to check your idle fuel pressure. Let us know what it is. That'll tell alot.

Ill find out what the idle fuel pressure is.

ive got a boost and egt but no fuel pressure and no datalogger but ido have a friend who has one. Never had to use it since it IS at a shop. But i will definately look into getting one for myself if you recommend it.

The fuel setup was stock star and the 30lb injectors and the wiring for the afc is correct, this is the second one ive had and i got the wiring diagram from this site.

Originally posted by Ruben Lopez
The fuel setup was stock star and the 30lb injectors and the wiring for the afc is correct, this is the second one ive had and i got the wiring diagram from this site.

Even if the wiring is correct, the settings in the unti have to be correct as well. Make sure it's set on PRESSURE, 7in/7out, 4cyl, arrow up.

Thank you for that, i was arguing witht the guy that set it up that i remember putting my old one to 7 and 7 but he was sure it was 6. Were going to the dyno later today to set the afc

well after actually getting the car it wasnt JUST the ECU or it wouldve been fixed the day before. It was that little black box that comes with the star kit. Its kinda like a missing link, well anyway it had a short in it so that was an easy fix. After that everythings back to normal, just breaking her in on 5psi for now.

Congrats, now just get a EGT and Fuel pressure gauge so you don't blow her up :thumbsup