RTEK 1.8, 4 x 750cc injectors, Apexi Neo MAXED - STILL LEAN UNDER WOT
 

So... I'm running an RTEK 1.8, 4 x 750cc injectors and my Neo MAXED, but, still lean over 50% throttle. (By lean I mean 13:1 AFRs at WOT)

It will hold mid-11s AFR up until than...

What you guys think? Time for larger secondary injectors?

Could it be that I'm using a stock s5 turbo?

For engine / exhaust info please see my signature below.

Thanks for your help guys,
-Chris

Are you using a T2 AFM?

If your running the stock turbo there is no way that you could be maxing 4 750cc injectors. It simply can't flow that much air (unless of course its a hi flow)

Yes.. It's running a s5 turbo MAF

I know my turbo has been ported as it holds boost well throughout rpm range with 3" exhaust behind it and 2.5" intercooler piping to a fmic ... I don't think a "stock" turbo could do that.... All third or forth high load pulls

I ran stock turbo, 14psi with 550/750 and did NOT max out the injectors so no way in hell that is the issue.

first thing that comes to mind is loss of fuel pressure, could be caused by:
Bad fuelpump
Clogged fuel filter
Something wrong with the FPR

I had a clogged filter once, as soon as boost got over 8psi it could not flow enough and would run very lean

Fuel filter recomendation? I'm drawing through a Summit canister fuel filter now which should flow double stock

Pretty much any filter will do, as long as the connections have the same diameter, i believe somewhere around 8mm

I ran stock before this one, and would prefer it.
but i had these issues 1 day before a race so i had to go to a local parts store and had to pick just a random filter with the right connections.
Flows more then enough for my 400hp.

Filter is the cheapest and fastest option to test, and if thats not it, a new filter never hurt anyone! (Some people forget they should be changed every few years!)

Yeah... But i changed my filter cartridge fairly recently

This filter BEFORE my IN-LINE Walbro 255 pump

http://www.summitracing.com/parts/sum-g1507

This is not the right filter..

Flow is enough, but it is stated as "Up to 15psi pressure", so that would mean that this is a filter for carb'ed engines, not fuel injected

Also, if you look at the applications list, it shows that this is for carburettor only

http://m.summitracing.com/parts/sum-g1507/application/

^ Bingo. Change that out very quickly.

I hope you're using high pressure fuel injection rated fuel hose.

Yes.. Fuel injection hose.. The filter is BEFORE my fuel pump and therefor has NO pressure going through it.
I don't see how this could be an issue... Grrr

Guess i could try removing it and istalling stock Turbo2 filter AFTER pump ??

Even though it is before, it could still be restricting your flow.

Wait.. what?

You mounted the filter inside the tank or what?

Gas tank to canister filter to INLINE pump

You had me fooled by the fact that you own a FC, as this is the 2nd gen section...
Adding the fact that you own a 1st gen with a totally different fuel setup would have helped in regards to solving the problem..

I think the gravity feed to that pump is insufficient..
You may need an in-tank walbro, with a normal fuel filter to keep up with your fuel demands

I'm not going to swap gas tanks on a "i think"... The pump is the in-line version and should flow exactly as the in-tank version.
The ONLY advice i've gained here so far is it MAY be my fuel filter and my turbo SHOULDN'T be able to max out 4 x 750cc injectors.... Everyone has read the engine DOES have a large streetport right?

^+1 on the fuel filter restriction. Try a fuel flow volume test to see what the system can physically supply. What fuel pressure are you running and how is it regulated?

If that checks out, I'd suspect one of your secondary injectors isn't wired correctly.

As for your setup:
Your injectors flow enough fuel for a stock S5 turbo.
Fuel pump is sufficient.
Streetport doesn't matter. It can't be big enough to affect it this much.

S5 fuel rails... Using stock rail-mounted regulator

Ok... I'll try eliminating the canister filter BEFORE the pump and install a stock Turbo2 filter AFTER the pump this afternoon

How sure are you that you have 720 injectors?

For got to mention...I'm running rtek 1.8 with 720s,extended street port, stock turbo, and all supporting mods. My car runs RICH!! But on rteks website it states it you don't run 720 with the 1.8 it would lean out and cause engine damage. Which is why I asked if you were sure about your injector size.

Had them cleaned and cc'ed about a month and a half ago... Lol.. My injectors are awesome.. I watched the test... The RC injectors have a beautiful conical atomization.. Way more atomization than the Injector Dynamics... They just have three large jets of fuel.. Lol

Damn...if youre sure you have 720s then I'm not sure what could be wrong. Have you tried calling rtek? You should start were everyone else said...the fuel filter. Lol what pump are you running?

Oops nevermind...i just saw you already answred my question. lol

had to order a filter... none in stock at three stores... Will let you know tomorrow...

NOTE: filled up with different brand gas and no change... just ruling that out.

did you check to see if you had a fuel pressure drop when driving?

the filter before the pump could easily be the problem, but if its not try "T" ing the boost gauge into the fuel pressure regulator hose, the n00b mistake with a T2 is just to assume every nipple in the intake sees vacuum AND boost, and they do not. there is a port there that is ONLY vacuum, so you end up really lean in boost.

Your point is well taken... BUT, i'm running my vacuum source directly off the s5 LIM.. Inside face.. Half way up runners.. That single nipple between and a little lower than the injector bosses.. The one that angles towards the rear of the engine.. THAT should be a direct port and i've veritfied it see's a strong vacuum idling... Have't check if it see's boost but will look into that after i swap my filter setup.

look into it, it may not do what you think it does.

I would like to point that your large streetport would not in any way help you use that much fuel. Personally i would be running an aftermarket FPR as soon as I changed injectors. It is a fuel pressure problem whether it is from the filter or the regulator. Either that or your wideband sensor is completely fucked.

If your still waiting for that filter why not just try bypass it for the purpose of the test.

I'm not going to risk hundreds of dollars in hurting my injectors for a $25 filter.. It will be here tomorrow :-)

Canister filter removed.. Stock turbo2 filter installed AFTER pump... Seems the richest i can get it to run is 11.7-12.2 at WOT
Also gonna check volts at pump... I'm still using the stock FB wires

Have you checked fuel pressure yet? I'd be installing an aftermarket fpr

^ +1

How would i install a fpr with s5 rails?

Use a S4 rail, or cut off the fpr and weld in a bung with hose connector

11.5 volts at pump... 13.9 volts at battery... Guess i'll be rewiring that.. Lol

Is this an issue that suddenly developed or are you still troubleshooting the initial swap?
Does it go lean under 3500 rpm, over 3500 rpm, or always?

I still suspect the secondary injector wiring. With the key on, ground out the signal wire at the ecu and listen for the injector to click.

Walbro's are rated at 12v anyway, so 11.5 vs 12 probably isn't going to change much. If the voltage drops a lot under load, then that's a different story.
You should have higher than stock fuel pressure with a stock regulator and walbro 255. So another FPR is going to be a band-aid, at best.

I remember someone mentioning about the S5 ecu needs the fuel pressure regulator solenoid plugged in, even if it is not attached to anything else. I know you said full S5 swap, but do you have your full solenoid rack attached?

This is initial troubleshooting with new engine... Just finished breakin miles...
I occassionally get a little stumble when the secondaries kick in around mid-3k rpm range, so, i'm fairly certain they are working... I don't go WOT under 4000 rpm

Well one of them could be. Have you run it without the SAFC or at 0% correction? Something major has to be wrong if you have to use the SAFC just to get it back to near stock AFR's.

Here's my crazy theory: Running 3 injectors with a MAF signal modified by 50% may be able to keep your AFR's near your target. Once the MAF opens more than 66% (+50% from the SAFC) the ecu reads 100%. The SAFC can't modify the signal beyond 100% and the 3 injectors can't keep up. (See, Math can be useful! :D)

Homework for you in order from easiest to most likely to require the fire department:
Check secondary injector wiring, or all of them since you're in there
Confirm boost coming from nipple feeding the fuel pressure regulator
Fuel pump voltage under boost
AFM output checks out according to the FSM
Fuel pressure under boost

Well.. I suspect my secondaries.. Did a pull starting at 3k rpm with low-11s afr... Right at about 3600 rpm it starts going lean... U can just watch to numbers climp past 12.5
So, i guess i need to check my secondaries wiring as I know the injectors themselves are golden... Ignition on > gound out secondary signal wires a ECU > listen for injector "CLICK"?? .. Or do i supply 12v?

You just supply the ground to the signal side and listen for the click. Do not ground out the 12v side as you may burn up the injector driver. Just do a quick touch when grounding. You may want to use some extra wire so you can stand right by the intakes when listening.

Your not listening to anything that knowledgeable members are suggesting. Your just gonna end up chasing your tail around. Have you changed the filter yet? Make sure you have a proper high flow EFI fuel filter. Also I would look into upgrading to a 2nd gen sending unit and fuel pump. I've seen threads on putting them in 1st gen tanks. But the GSL-SE tank is the best because it has a baffle to prevent the fuel pump from starving.

First thing I would do is check fuel pressure, make sure the pressure raises accordingly with RPM. If your injectors were recently cleaned/serviced I doubt they shorted out so quickly, unless they're really cheap quality.

And as people have suggested, I would upgrade to an aftermarket fuel pressure regulator to support your upgraded fuel injectors. Preferably one with a gauge like an Aeromotive unit.

I'll check for "click" this afternoon by grounding injector signal wires at ECU w/ ignition on. I just want to rule that out before i start "chasing my tail"... I even left Rx7 at home so i'm not working over hot engine this afternoon... I should be able to get right on it after work.
Same wiring harness -> previous engine died from front apex seal failure... REALLY curious about front secondary injector activation... Will let you know

Tested all injectors at ECU with key on... All same voltage... Primary Injector Dynamic (modified Bosch) injectors make loud "click" when grounded that i could easily hear while probing the ECU... Secondary RC injectors make much quieter "click" that i had to run a jumper wire under the hood from the ECU to hear the injectors while grounding.
So.... Yeah.
.... I guess i need to fake a load now, rev to 4k rpm while probing the ECU and look for a voltage drop in the secondaries with my DVM??? *Confirm signal leaving ECU to fire them? *Or, how do i do that?*

... Is my wideband dieing? I have an AEM UEGO wideband.. It does NOT preheat i've notived and rarely reads FULL lean when decelling... THESE NUMBERS ARE ONLY WHILE DECELLING... Will read mid to high 16s until it warms up (five minutes maybe) than will usually read 17.7-18.0 until it gets REALLY warmed up (hard driving) when it will read --- (full lean)... Prob just need replacement o2 sensor? I really doubt the controller went bad

might be, i think mine is doing the same thing.

did you try the vacuum hose yet? it'll take you 5 minutes.

www.foxed.ca has the S5 training book, it does mention when the secondaries come on.

.. I have an old Sun dwell tach i could wire into secondary injector wires... It would output in a 0-90 scale (which can closely represent duty cycle)... Hmmm

Here's how you do it...*http://www.gassavers.org/showthread.php?t=7714

how far is your sensor from the turbo?

have you ever run these injector combo before with the 1.8? did it ever run normal, or did this problem happen just recently?