IneedBoost

Like the title I have a blacktop stock sr20det with a fuel cell and -8AN fuel lines. Now the car starts and runs but when revved it immediately breaks up and seems to starve for fuel. Did all normal tests such as injector spray pattern/maf/coolant temp sensor resistance, checked for boost leaks. The motor came from a friend which I've driven the car it was in. The Ecu is a Mine's tuned Ecu. I'm running an aeromotive A1000-6 fpr and a walbro external 255. Any ideas? Would it need a tune just for larger fuel lines?? I'm stumped

jr_ss

Have you set the base fuel pressure? Have you checked timing? Just because it came from a "friend" doesn't mean he knew what he was doing.

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My SR20VET

IneedBoost

Base fuel pressure is set at 43psi. What I meant by it came from a friend was that the motor was in his car running. I drove it and it was fine. It didn't have the fuel cell or fuel lines in/on it when he had it. I modified the fuel system. Factory fuel rail with -8 fittings welded onto it.

IneedBoost

Haven't checked timing yet but I will asap

IneedBoost

Also should mention I removed the a/c comp and haven't changed the belt just yet. I haven't driven the car yet either being that it's a bare shell.

Def

No you don't need for fuel line changes - you retune for fuel base pressure changing. And you set it at 43 psi with the vacuum line OFF right?

You really need a wideband to tell if the engine is rich or lean. You can have both rich and lean misfires, and very few people can tell the difference.

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S13 Hatch - Goes around tracks quickly
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IneedBoost

Yeah it was set with the vac line off. I have an Aem wideband just waiting for a buddy to weld the bung on the downpipe for me. I know for sure it was running rich but the fuel rail was leaking a bit at one of the welds.

IneedBoost

Ok got my sr20det running again. Here's the setup.

Stock blacktop sr
Stock t25, injectors and everything
Circuit sports side feed fuel rail
-8AN fuel lines
Rci 12gal fuel cell
Walbro 255lph external pump
Aeromotive A1000-6 fpr set to factory 43psi
Mine's tuned Ecu for 10psi
Custom wired to relay/circuit panel.
New Ngk bkr7e's

Reset timing to factory 15* TDC and cas aswell

Now the problem. It idles ok with the wideband reading around 12.8-13.5. But when revved in neutral under no load the wideband reads lean and it breaks up trying to increase rpm.

I boost leak checked it and found no leaks. Trying to see what I should check out next.

Thanks

IneedBoost

Update! Videos
Sr20det lean idle(2): http://youtu.be/-PqQsYT5q1w
Sr20det lean idle(1): http://youtu.be/B0eH2vOmHc4

cotbu

I hear detonation, your idle afr is not 12.8-13.5 it's 17 to off the chart.
Check fuel pump, wiring, lines, filter and sock/strainer.
Change video orientation you got lucky on this one if I didn't hear what sounds like detonation probably wouldn't have relied

Sent from my Highly Tuned Galaxy S3.4!!!

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LoverTechnologies "Half Broken Things!"

IneedBoost

The other day it's was around 12.8 noticed when I was leaving that the test pipe wasn't tight and the bolt vibrated out. I checked the fuel pump it's getting 14.3 volts lines are all new and getting fuel pressure isn't a problem both filters are good also I have a 100 micron filter before the pump and a 10 micron after. I'm thinking that it's not getting good grounds.

cotbu

With an upgraded fuel system you shouldn't be as lean as you are, get a tune or it's going to detonate BTW 15deg is btdc
G/L

Sent from my Highly Tuned Galaxy S3.4!!!

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LoverTechnologies "Half Broken Things!"

IneedBoost

As stated up top it has a tune tried swapping to a stock Ecu and it's no different. I know what 15 deg is. I set it there. It's stock injectors and everything but fuel system. The injectors are probably not spraying as best as they could causing it to go lean because they operate on ground

cotbu

your at idle correct the car is running injectors are firing fuel is being injected, just not the proper amount for the air. I know you don't know how to tune or you wouldn't be running a mines tuned ecu. so I suggested check because these are things you can do for free! damn florida my bad your right t's a ground problem even thought you said and switching ecu changed nothing. any good parts on that car waiting for your for sale thread

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LoverTechnologies "Half Broken Things!"

IneedBoost

Lol the car is custom wired... The fuel pump is wired to a relay that gets power straight from the battery. So of course it's going to get good voltage. It's grounded and powered by the battery only. Did you not read anything posted earlier? There is no sock or strainer the pump is mounted under the car with inline filters like I also said earlier. Wiring, I am going to go over like I thought it might be an improper or bad or missing ground! Get off your high horse and relax. I don't know how to tune because the ecu my motor came with is tuned by mines lol your funny bud. I didn't buy the motor then say I need a tune let me buy a Mine's Ecu. It came with it. Either way I'll figure it out. Thanks for your "help".

Def

Your engine needs a really good ground, as do all the things that operate to ground. If you custom wired stuff you could very well have way too much stuff going to a ground wire that is too small.

I would recheck grounds and verify fuel pressure tracks with manifold pressure.

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DEFSPORT

IneedBoost

That's what I'm planning on doing tomorrow my car is at the shop. Thanks! I was thinking that the guy who wired it didn't quite finish so I'll be calling him aswell

cotbu

have some one verify the tune also, most of the mines tunes i've seen are boost up with z32 mafs

still on my

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IneedBoost

Again like I said in my original post. The motor was running and driving just fine in a friend's car.

IneedBoost

Rewired my grounds all with 4 gauge wire here's how it's setup
- battery terminal to chassis
- battery terminal from battery to aftermarket fuse panel ground.
From fuse panel ground to ground location on intake manifold.
From intake manifold to chassis.

Checked all for voltage drop. No drops in voltage at any spot. Tried swapping out the coolant temp sensor still no change. What I did notice though was that the motor struggles to start when cold. When it does start and it's cold it instantly wants to die and will. When it warms up to around 175* to 180* degrees it will start ok and it will idle on its own.

cotbu

Have you pulled codes? If you have consult port connected and a program that can dump the bin, i can look at the tune. Try starting the car with the mafs disconnected, then tps, then coolant temp sensor, then means connect the previous disconnected.

Try raising the fuel pressure, you set the fuel pressure with the engine running pulling strong vacuum, set it to 3bar, 43.5psi with vacuum line disconnected and plugged. raise it by 5psi just a test. set i back if there's no change in starting.

Leaky injector, hard starting, start the engine with the throttle wide open, if it starts check for leaking injector(s) or flooding
Start with this one, before raising the fuel pressure.

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LoverTechnologies "Half Broken Things!"

IneedBoost

Ive tried changing fuel pressure made no difference and a new coolant temp sensor. Here's a video from today of the afr's Sr20det idle issue: http://youtu.be/X21MWTR86ZE

IneedBoost

Update: the motor is not getting any injector pulse when cranking/idling. Only getting pulse once the motor is started and given throttle. Realized it only is pulsing when the alt takes over. Tested with noid lights

cotbu

You do know that sounds ridiculous right? I mean your description not the symptoms you describe.

During cranking fuel has to be injected by the fuel injectors or then engine wont have fuel to start or rev!
Only getting pulse once the motor is started and given throttle
During cranking the injectors are batch firing.
Either you found a new problem because you said, you checked spray pattern, that would indicate to most, that you pulled the fuel rail and spun the CAS. correct? You wouldn't need a noid light to confirm the injectors are firing, but that also means the injectors are get battery (voltage?) and a ground trigger from the ecu. They are/were working.

Battery voltage is important in tuning, mafs and injectors need battery voltage. At start up, the voltage is around 14v. lag times are usually set from that, but can be adjusted for a specific setup. (tuning)

I'll still offer to look at the mines bin for you. Most of the mines tune's I seen are for larger injectors than stock. Why would tuning company make a tune for a stock setup? 10psi is below stock boost, maybe the cranking tables, timing, and fuel maps aren't correct, let alone the k at this point. Let me know something yes or no works. Unless you can get a stock ecu in there,
to elimidate, the whole tune is the problem theory.

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