new intake/tb/injectors, why so lean?
Discussion
Please help someone too stressed to see the wood for the trees (me 
). I've just changed the intake, throttle body, fuel rails and injectors, and am super-lean - see screengrab: https://dl.dropboxusercontent.com/u/95930/Monaro/E...
You can see that I start off with vaguely ok AFR (I richened up the VE a bit just in case), which makes me think my injector data (Siemens 60lb, Banish data) is probably fine (though annoyingly my AFR is out by a factor of ~2, which is about what I've changed the injectors by!). It starts spiking lean, and eventually stays there. I'm running speed-density, so am confused if an air-leak could cause such a thing, since wouldn't this be metered? The intake is a used LSXR, so plenty of potential for wrongness.
I haven't got a gauge to check rail pressure. It now occurs to me to double-check wiring since I'm effectively 200% of stoich (so 1 bank of injectors intermittently not functioning?).
The TB is a cheap Chinese jobber, and I think is the cause of some horrible wailing noises, which I think corresponds to when the AFR is lean...I do wonder if the IAC channel is causing the wailing though, the noise may correspond to IAC open. I may spring for a Nick Williams TB (throw money at the problem...), but not sure if this will cure my leanness. Note I was fiddling with the stop on the TB to try to get the IAC counts reasonable during the screengrab.
I think I'll need a new WB02 soon, but the narrow-band 02 seems to sanity-check the WB02.
Any thoughts appreciated!
). I've just changed the intake, throttle body, fuel rails and injectors, and am super-lean - see screengrab: https://dl.dropboxusercontent.com/u/95930/Monaro/E...You can see that I start off with vaguely ok AFR (I richened up the VE a bit just in case), which makes me think my injector data (Siemens 60lb, Banish data) is probably fine (though annoyingly my AFR is out by a factor of ~2, which is about what I've changed the injectors by!). It starts spiking lean, and eventually stays there. I'm running speed-density, so am confused if an air-leak could cause such a thing, since wouldn't this be metered? The intake is a used LSXR, so plenty of potential for wrongness.
I haven't got a gauge to check rail pressure. It now occurs to me to double-check wiring since I'm effectively 200% of stoich (so 1 bank of injectors intermittently not functioning?).
The TB is a cheap Chinese jobber, and I think is the cause of some horrible wailing noises, which I think corresponds to when the AFR is lean...I do wonder if the IAC channel is causing the wailing though, the noise may correspond to IAC open. I may spring for a Nick Williams TB (throw money at the problem...), but not sure if this will cure my leanness. Note I was fiddling with the stop on the TB to try to get the IAC counts reasonable during the screengrab.
I think I'll need a new WB02 soon, but the narrow-band 02 seems to sanity-check the WB02.
Any thoughts appreciated!
My fugued brain eventually realised it probably isn't a bank of intermittent injectors because I only have the one WB02, and it's naturally near the collector.
FWIW I've ordered a Nick Williams TB. Might not be that, but this is the excuse I need for expensive hardware.
The benevolent NA gods still watch this forum, even if they don't intervene on this realm. Praise be.
FWIW I've ordered a Nick Williams TB. Might not be that, but this is the excuse I need for expensive hardware.
The benevolent NA gods still watch this forum, even if they don't intervene on this realm. Praise be.
Retrogressive changes one at a time. Can you vacuum test the intake. I would always be suspicious of why the last owner sold if you don't' know him. Could have hairline crack or poor seals?
Why the huge injectors? The Aussies have shown that you want injectors working on the limit, 60lb wont be any where near that with your setup. Can you change them back?
Chinese low quality stuff is always suspect, buy the NW, its good stuff.
Why the huge injectors? The Aussies have shown that you want injectors working on the limit, 60lb wont be any where near that with your setup. Can you change them back?
Chinese low quality stuff is always suspect, buy the NW, its good stuff.
The old owner is on here, I trust him. Postie may have dropped it though, and maybe I should have renewed the seals.
I chose those injectors because I have good data for them and could not find a more appealing alternative. That, and the option of boosting or fancy fuel later. I felt my build is mostly conservative enough that I could handle sub-optimal injectors. I might be wrong.
Unfortunately it was mostly an all/nothing install; 3 vs. 4 bolt TB, and don't really want to remove the non-standard o-rings from the new injectors to swap onto the old ones now they are on there.
I chose those injectors because I have good data for them and could not find a more appealing alternative. That, and the option of boosting or fancy fuel later. I felt my build is mostly conservative enough that I could handle sub-optimal injectors. I might be wrong.
Unfortunately it was mostly an all/nothing install; 3 vs. 4 bolt TB, and don't really want to remove the non-standard o-rings from the new injectors to swap onto the old ones now they are on there.
I'm sure it will come right in the end, just got some waiting to do for bits now - even if it isn't those bits I'll have eliminated them, and got to check over the intake again when it's off. FWIW I enjoy the process of putting it together, just so many variables this time (used bits, cheaply manufactured bits) seems to have bitten me on the arse!
KMud said:
The old owner is on here, I trust him. Postie may have dropped it though, and maybe I should have renewed the seals.
I chose those injectors because I have good data for them and could not find a more appealing alternative. That, and the option of boosting or fancy fuel later. I felt my build is mostly conservative enough that I could handle sub-optimal injectors. I might be wrong.
Unfortunately it was mostly an all/nothing install; 3 vs. 4 bolt TB, and don't really want to remove the non-standard o-rings from the new injectors to swap onto the old ones now they are on there.
Have you milled the heads? If so could be the valley angles???I chose those injectors because I have good data for them and could not find a more appealing alternative. That, and the option of boosting or fancy fuel later. I felt my build is mostly conservative enough that I could handle sub-optimal injectors. I might be wrong.
Unfortunately it was mostly an all/nothing install; 3 vs. 4 bolt TB, and don't really want to remove the non-standard o-rings from the new injectors to swap onto the old ones now they are on there.
Guessing that the 'old' owner simply upgraded to an all aluminium intake, so that they could up the boost on their turbo set-up. They would, of course, be highly embarrassed if the intake was faulty in any way, as it worked fine the last time it was used. And in the spirit of things would provide a full refund, including any postage costs.
ArnieVXR said:
Guessing that the 'old' owner simply upgraded to an all aluminium intake, so that they could up the boost on their turbo set-up. They would, of course, be highly embarrassed if the intake was faulty in any way, as it worked fine the last time it was used. And in the spirit of things would provide a full refund, including any postage costs.
Did you have any high boost through it?(And I did say "if you didn't know the owner")
Ran 17.5psi on the dyno
Launch boost was 10psi
Peak was around 20, maybe 25psi
Ran no more than 20-passes. On the last two passes, it ran well enough to win both Supercup and Pro-ET.
Changed at the end of my trials in 2013 ready for the full 2014 season, where I hoped to run some serious boost (at York - as if).
Launch boost was 10psi
Peak was around 20, maybe 25psi
Ran no more than 20-passes. On the last two passes, it ran well enough to win both Supercup and Pro-ET.
Changed at the end of my trials in 2013 ready for the full 2014 season, where I hoped to run some serious boost (at York - as if).
MyM8V8 said:
Why the huge injectors? The Aussies have shown that you want injectors working on the limit, 60lb wont be any where near that with your setup. Can you change them back?
Absolutely......you want the injectors working hard to get the best spray pattern. Been there, done that, went back!!!! Only went up to 36lb ones for my ute with big cam and heads!!!!TheLeatherman said:
MyM8V8 said:
Why the huge injectors? The Aussies have shown that you want injectors working on the limit, 60lb wont be any where near that with your setup. Can you change them back?
Absolutely......you want the injectors working hard to get the best spray pattern. Been there, done that, went back!!!! Only went up to 36lb ones for my ute with big cam and heads!!!!TheLeatherman said:
Absolutely......you want the injectors working hard to get the best spray pattern. Been there, done that, went back!!!! Only went up to 36lb ones for my ute with big cam and heads!!!!
I'm sure you're right - I struggled with connectors, injector (body) sizes, quality of data, availability of the injectors, availability of corresponding fuel rails, silly future ideas...these will do for now. Another day...KMud said:
I'm sure you're right - I struggled with connectors, injector (body) sizes, quality of data, availability of the injectors, availability of corresponding fuel rails, silly future ideas...these will do for now. Another day...
So you fitted LS2 injectors with Uscar connections as well?Gassing Station | HSV & Monaro | Top of Page | What's New | My Stuff