RTEK 1.8, 4 x 750cc injectors, Apexi Neo MAXED - STILL LEAN UNDER WOT
05-09-12, 10:17 PM
#53
... Confirmed primary & secondary injector signal out of ECU using dwell meter.. Simulated load by disconnecting TPS and plugging pressure sensor vacuum line than reving to 4k rpm.. Secondaries started firing a little over 3500 rpm
Anyone actually running some similar to my setup WITH a wideband?
Anyone actually running some similar to my setup WITH a wideband?
05-10-12, 12:29 AM
#57
If the injector signal has been confirmed, then it is unlikely that slapping on additional grounds will do very much. Not to mention, fixing the original ground would be the way to go as the effectiveness of any additional grounds would be compromised by a faulty original.
This still sounds more like a fuel delivery issue than an injector issue. Have you been able to confirm fuel pressure while running?
This still sounds more like a fuel delivery issue than an injector issue. Have you been able to confirm fuel pressure while running?
05-10-12, 01:08 AM
#60
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At first you said the problem is when going WOT.
Seondairies come on at 3800, regardless throttle
If you can accelerate up to redline on half throttle without issues, it is not a voltage issue.
The alternator doesnt care about WOT, just revs.
If it is indeed only at WOT, it is probably when boost is kicking in up to a certain level?
Try flooring it from low revs and see when AF drops at what boost level and rpm
After that, accelerate light throttle to maybe 5500 and try flooring it.
If AF changes at the same boost level, it is 100% fuel related.
Seeing that you can not get it right with the safc, it is probably fuel pressure drop
Seondairies come on at 3800, regardless throttle
If you can accelerate up to redline on half throttle without issues, it is not a voltage issue.
The alternator doesnt care about WOT, just revs.
If it is indeed only at WOT, it is probably when boost is kicking in up to a certain level?
Try flooring it from low revs and see when AF drops at what boost level and rpm
After that, accelerate light throttle to maybe 5500 and try flooring it.
If AF changes at the same boost level, it is 100% fuel related.
Seeing that you can not get it right with the safc, it is probably fuel pressure drop
05-10-12, 08:51 AM
#62
I'm basing everything on my wideband numbers... I wideband i suspect has issues.. I've decided to stop troubleshooting until i install a new sensor.. Already in the mail 
However, i will clean up my ECU grounding and pull a spark plug to see how they look this afternoon
However, i will clean up my ECU grounding and pull a spark plug to see how they look this afternoon
05-10-12, 09:05 AM
#64
Junior Member
Yikes. Your fuel system sounds sketchy. Does your car run a 3/8s supply fuel line??? That voltage is way to low at the pump. Voltage will make a difference on pump output. The pump should get its power through a good relay. That relay should have a minimum of 14-12 gauge wire going straight to the battery or back of alternator. It should be fused. How is the fuel pump ground?? I also recommend running an after market fpr. There is never an issue having too much delivery. Do you have any pictures of your fuel system setup? How is the injector data entered in the ecu?
Cheers,
Ryan
Cheers,
Ryan
05-10-12, 10:43 AM
#65
Well...glad your secondaries are working. At least your wideband is giving you relative readings, so it's still a useful tool. Just to confirm, you are still running with the SAFC maxed out? Have you tried running without it? Your setup really shouldn't require one.
I'm concerned the SAFC is muddying the water as far as diagnosing a problem.
That autozone fuel pressure kit should work. Install, tape the gauge to the windshield and take a spin (windows rolled up, just in case).
On a sidenote: I think your car is awesome and it's going to be a blast when running well!
I'm concerned the SAFC is muddying the water as far as diagnosing a problem.
That autozone fuel pressure kit should work. Install, tape the gauge to the windshield and take a spin (windows rolled up, just in case).
On a sidenote: I think your car is awesome and it's going to be a blast when running well!
05-10-12, 12:54 PM
#66
Here's what we think we know so far. You have an S5 turbo. When you say that it's "ported" what exactly do you mean? Does it have a new compressor wheel that flows more?
If it doesn't and only has a stock wheel then that moves us to your fuel injectors. If you do in fact have the injectors that you say you do then you have more injector capability than you can possibly use with that turbo. You can not and will not max them with your turbo UNLESS you have insufficient fuel pressure or flow to them. You stated that you have a Walbro 255 pump. Are you sure it's a real one and not a fake? There are lots of substandard poorly flowing fakes out there that do say Walbro on them.
If your pump is fine, what is your fuel pressure? If you don't know this then there is no way that you can arrive at the conclusion that you don't have enough injector. From what you've told us it seems that the best place to start is with that carb fuel filter that you have before the pump. I know it says not above 15 psi and that you have it before a pump but remember it's not supposed to be drawn through even on a carb. It's designed to have fuel pushed through it. Run a test. Remove this filter completely and see how everything is. That little bit of time isn't going to harm anything.
Get rid of that S-AFC. It stands for Stupid Air/Fuel Computer. I have always refused to touch them. It's like using a band-aid to fix something that only surgery can or in your case a band-aid on the outside of a cast.
05-10-12, 01:02 PM
#67
As i've already noted... The filter has been swapped out > still same issue. My plan is to pick up a fuel pressure diagnostic tool from AutoZone this weekend to:
- test for pressure drop while manually grounding injectors (car not running, key on, pump off but pressurized)
- test running at idle pressure
- test boosting pressure
...Hoping to have new wideband sensor by than too
- test for pressure drop while manually grounding injectors (car not running, key on, pump off but pressurized)
- test running at idle pressure
- test boosting pressure
...Hoping to have new wideband sensor by than too
05-10-12, 04:07 PM
#69
Senior Member
The ECU's ground cables (2 of them together) are bolted to the engine block in the area underneath the TB's elbow. The ECU doesn't have to be bolted down to the frame. At least that's how it is on my S4-TII.
Make sure that ground wire is on good. Otherwise it will affect injector function. I know from personal experience.
Also, sure the fuel pressure regulator is getting manifold pressure? And, is a fuel psi gauge installed? Fuel pressure must go up @ 1:1 w/boost.
05-11-12, 10:42 PM
#70
UPDATE: with car idling i grounded each secondary injector at ECU... Front and rear both bogged engine down and killed it = they are working and i have already confirmed secondary injectors are getting signal while running (earlier post)...
Fuel pressure has been checked... According to gauge, at idle its sitting at 50-52 psi (i assume this may not be accurate, but i was checking for PRESSURE DROP)... Under load (no boost) it drops to 42-44 psi and raises up and HOLDS 52-ish psi at 8-9 psi boost. AFRs hit mid-12s under WOT... For the skeptics out there, here's proof: (at beginning of video, the needle is pointed at 50-52psi.. For referance) http://www.youtube.com/watch?v=mjd82...e_gdata_player
So... All i got is either my wideband is **** (new sensor in mail), i need larger injectors and/or time for stage 2 RTEK
... Yup
Fuel pressure has been checked... According to gauge, at idle its sitting at 50-52 psi (i assume this may not be accurate, but i was checking for PRESSURE DROP)... Under load (no boost) it drops to 42-44 psi and raises up and HOLDS 52-ish psi at 8-9 psi boost. AFRs hit mid-12s under WOT... For the skeptics out there, here's proof: (at beginning of video, the needle is pointed at 50-52psi.. For referance) http://www.youtube.com/watch?v=mjd82...e_gdata_player
So... All i got is either my wideband is **** (new sensor in mail), i need larger injectors and/or time for stage 2 RTEK
... Yup
05-12-12, 12:17 AM
#71
Seems like you have your vac source for your FPR hooked up incorrectly.
Base pressure , we'll call it 50 psi should be set with the fuel pump running, but engine off. Fuel pressure at idle should be lower, lets say 45 psi than base pressure because vac is being pulled on the FPR. As you accelerate and reach 0psi fuel pressure should return to base pressure (50 psi) then rise 1 psi per pound of boost, so 8-9 pounds should equate to 58-59 psi of fuel pressure. Does it not seem strange that your fuel pressure at idle is the same as your fuel pressure at 8-9 lbs ???
What nipple are you using for the vac signal to the FPR?
As stated previously, there is NO WAY ON EARTH that you are maxing out your injectors.
Its possible that your wideband may need calibration, but it doesn't seem to be too far off from what most would expect.
An upgrade to 2.1 would be nice, especially if you have bigger plans for this setup. SAFC is pretty weak and starts screwing with timing as you make fuel adjustments = undesireable.
Base pressure , we'll call it 50 psi should be set with the fuel pump running, but engine off. Fuel pressure at idle should be lower, lets say 45 psi than base pressure because vac is being pulled on the FPR. As you accelerate and reach 0psi fuel pressure should return to base pressure (50 psi) then rise 1 psi per pound of boost, so 8-9 pounds should equate to 58-59 psi of fuel pressure. Does it not seem strange that your fuel pressure at idle is the same as your fuel pressure at 8-9 lbs ???
What nipple are you using for the vac signal to the FPR?
As stated previously, there is NO WAY ON EARTH that you are maxing out your injectors.
Its possible that your wideband may need calibration, but it doesn't seem to be too far off from what most would expect.
An upgrade to 2.1 would be nice, especially if you have bigger plans for this setup. SAFC is pretty weak and starts screwing with timing as you make fuel adjustments = undesireable.
05-12-12, 02:16 AM
#75
Hmmm... It really shouldn't make a difference as far as those particular nipples are concerned, but there certainly seems to be something wrong with your fuel pressure. I have used the FPR nipple on multiple engines and never had a problem.
I believe you stated that you re-wired the fuel pump, have you verified the pump voltage when the problem occurs? If not run some leads from the pump terminals to a multimeter that is visable in while driving (probably best to have a friend along). If voltage checks out then perhaps your FPR is the culprit.
I believe you stated that you re-wired the fuel pump, have you verified the pump voltage when the problem occurs? If not run some leads from the pump terminals to a multimeter that is visable in while driving (probably best to have a friend along). If voltage checks out then perhaps your FPR is the culprit.