MerloZ Posted October 7 Share Posted October 7 Recently finished a swap of a 2005 Cummins holset he351 onto my car. Swap went pretty smooth. Obviously I read other people need larger injectors but I'm just trying to hit boost a little bit as I've spent a lot this year. I've been trying to tune/ auto tune it in-between things for a week or two and it seems the moment I hit boost it goes lean. I am having trouble and some of it may be the o2 out of range filter on auto tune. I'm unsure if it is too rich or too lean but the o2 out of range comes all all over the board. Annoying but I think that's just my lack of time spent trying to narrow in the VE table it's weird it reads 22 are when it's clearly too rich. For example at idle I richen it and it goes from 11afr to 22 and goes out of range. Anyway. My VE table and engine was seemingly still going lean the moment boost hit. Table kept slowly increasing fuel till it hit 255 I then upped fuel pressure from 37 to 43 in hopes to get some extra CC's out of them thinking that's the issue. I changed required fuel in tuner studio. Original CC setting for injectors was 260 and I upped it to 295. Tried tuning it that way. Obviously autotune leaned things out and then started to richen up the boost area again. Cells Starting at 120 and now we are at 166. Still seemingly going lean. Injectors must be out of flow? It's just odd because I'm at 2psi of boost at that point and the stock turbo was pushing 12-13 psi. Interesting that just the size of the compressor housing is changing afr that much? I believe I know my answer is getting maybe the 440 CC injectors from Godzilla Just wanted to get some other opinions. Maybe I'm missing something. I was hoping to run lower boost maybe 17psi max and keep the stock injectors for now. I will also add in I did a quick table generator, it was maxed out Rich at the bottom (255)and close to that rich under boost. Maybe I'm the 40's everywhere else. It clearly was a bit too lean driving around in the 40's on the ve table but once it hit boost that was the fastest the cars been in a while. So where I'm currently at is maybe with the added fuel pressure I can bump my VE Table up in the 200's and it might be somewhat drivable under boost. If that's not the case I think I need injector upgrades? Let me know your guys thoughts. Thankyou. Stock injectors and fuel rail 240sx throttle body 255lph walbro Trigger wheel Ms2 Lc2 wideband He351 ported and enlarged wastegate Custom adjustable wastegate set top open 5mm at 16psi 3 inch exhaust Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 8 Share Posted October 8 You failed to specify what engine the stock injectors are for. If for an NA engine then yes, you need bigger injectors. If for a turbo engine then that isn't your problem. Have you gotten an msq from someone with a basic turbo setup and tried it? Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 8 Author Share Posted October 8 The injectors should be stock l28et injectors. I've been running a map from chickenman for years with that setup on the stock turbo. Too many backfires killed the thrust bearing. I will double check the type of injectors I have maybe they had non turbo injectors on the engine when I got it but none of it looked tampered with back then. If not the injectors than what might be the issue? Just the wideband going out of range? Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 9 Share Posted October 9 Ok, so stock turbo injectors. If you haven't raised the boost to much more than 10 psi you're ok with the stock injectors. The wideband sensor and controller need to be tested. Quote Link to comment Share on other sites More sharing options...
jonbill Posted October 9 Share Posted October 9 A couple of things that might help: When a cylinder doesn't fire, then the wbo2 reads full lean because the gas passing over it is atmospheric air. None of the oxygen has been used to burn fuel. This happens whether the misfire was because the mixture was too lean or because it was too rich. So when you're at 11 afr and go richer, it wont burn and so it shows lean. Telling TS that you have bigger injectors when you haven't changed them will make it leaner, because the calculation assumes that it can deliver the required fuel in a shorter time. Assuming your injectors are big enough for your power level, when you're maxed out on the VE table values (as your are) a larger required fuel value will give you more head room. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 9 Author Share Posted October 9 So I did increase required fuel and it gave me more head room but it didn't seem to affect it. How can I tell factory turbo injectors from non turbo ones? Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 9 Author Share Posted October 9 So I did increase required fuel and it gave me more head room but it didn't seem to affect it. How can I tell factory turbo injectors from non turbo ones? Also yes the turbo is set higher for ten psi but I haven't even been able to hit that yet. The moment its under boost it seems to go lean Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 10 Share Posted October 10 If you were running stock boost before this turbo change then you have turbo injectors because you'd have leaned out with NA injectors. When was the last time your injectors were cleaned? Have you checked each for proper function? Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 10 Author Share Posted October 10 The injectors have never been cleaned. When I originally built this engine I figured slap it on see if it runs and it always I have ran some fuel system cleaners through the gas previously for that reason. But never professionally cleaned. My injectors are brown, not green so that leads me to believe that they're factory turbo injectors because that's what they came off of. Also I was running 12.5 PSI with the factory turbo. Also, I apologize, I do have a front mount intercooler as well. With the old turbo I at one point ran 15 PSI of boost just for haha's and it did not lean out. . I guess we are thinking a wide band issue, If I had to take a stab at it I would guess it's the sensor. I believe I've cooked one before but it was on the stock. L28 downpipe. Once I read the manual I then bought a bong and put it about 2, 2 and 1/2 ft down the down pipe, it's probably a few inches past the bellhousing after 2 45 turns. A local friend of mine has some car meets and I always go to them and win an exhaust competition from spitting 3 ft flames, I believe this to be the reason the factory turbo went bad. Maybe the wide band is on its way out as well from all the flames? 1 Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 10 Author Share Posted October 10 I notice while watching the wide band on tuner studio while trying to auto-tune. I was adjusting the idle fuel cells. If I adjust them to 12.5 AFR like the engine usually likes at idle. The tuner studio number will sit around there for a few seconds and then go lean and out of rangem I'm not sure what my lc2 gauge is reading as it's hanging. Not sure if it reads 12.5 or if it reads 22 like tunerstudio does. However the lc2 gauge never showed me that issue before. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted October 11 Author Share Posted October 11 I'm going to try to re calibrate my sensor. I can't find much for testing online for it. I did recalibrate in the exhaust cold but it does say to do it out of the exhaust. It never read like this before I did this swap but I did do that recalibrattion. Weird because that's always how I've done recalibrations but weirder things are possible. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted November 5 Share Posted November 5 Ok. Quickly read through this. I see in your original post that you say you where running 10-12psi on the stock turbo. While i think you have something wrong those injectors will not allow you to run more than around 7psi i would assume. I ran the HE351cw turbo and L28et back in the day and I was maxing out 440 supra or rx7 injectors at the 17 psi range. And 17psi isnt a low number for that turbo and engine combo. 14psi netted me a 12.8 sec at 110mph 1/4 mile on street tires with a slipping clutch the whole way down the track.. My advice which comes from doing it the wrong way. Build up your fuel system and supporting mods first to handle almost anything you could throw at it and then start upping the boost. I blew my fair of head gaskets and pistons 20 years ago pushing the stock fuel injectors.... My current setup in my 84 maxima wagon is the stock l24e with a turbo manifold and stock turbo running stock boost. My fuel system is 550cc bosch injectors with aeromotive FPR, Flex fuel sensor, and a big enough pump to support more than the injectors can flow. I agree with the wiser more experienced posters who posted above. but i think your wasting your time and eventually money trying to keep the stock injectors. I remember when i switched to the Holset it took alot more fuel. it flows significantly more air than the stock turbo. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 8 Author Share Posted November 8 I agree and sure if like to not spend money but I posted this to figure out if I need bigger injectors. Below the top two rows of my fuel table my afr reads 11 then spikes lean. Do you think that's actually lean? Or just out of range. 12 psi on the factory turbo didn't seem to be an issue at all for the factory injectors.. hell I pushed 14 on that turbo before with steady 11 afr. These are factory turbo ones not NA ones. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 8 Author Share Posted November 8 Problem still persists. Changed fuel counts from 70-200 still does the same thing for top two fuel rows Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 9 Author Share Posted November 9 Right before it "bucks" it is at 15 psi and 11 afr. While bigger injectors might be the fix it also seems odd. How can 17psi run 440cc injectors out when I hit 15 no issue Only difference I see is timing right?. I know my timing is quite conservative. Anyway I could change fuel numbers and test the injectors or something. I'd rather not just throw money at it Car runs great with this turbo until it hits the top two rows on the ve table. After 4500ish. Just seems odd to me. It really doesn't seem like boost is kicking in and it's going lean. It seems more like the fuel table is fine and at that point it's rich all of a sudden and floods the plugs. I let off the moment it "bucks" It doesn't seem like detonation to me but I guess I've never blown up an engine. I'd say that's a good thing. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted November 9 Share Posted November 9 Its not the psi. Its The flow. The holset flows more air considerably than the stock turbo. Did you hold up the 2 and see the compressor size difference?I believe your out of injector or pump. Others have given you great advice. If you can't verify anything like fuel flow or pressure not much ww can do from afar. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 9 Author Share Posted November 9 Oh I forgot if I mentioned this in the thread. I replaced the O2 sensor and recalibrated it and I'm no longer making out the ve table. Like I mentioned before right before the "bucking" or the lean condition you think I may have from lack of injector I am at 15 psi and 11 afr at around 120 on the ve table. My old O2 was definitely reading bad and was doing the same thing but much much worse. I know this turbo flows way more air. What is a way I can test if the injectors are maxed out. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 9 Author Share Posted November 9 Others have told me it's not the injectors and you have said it is so I just don't know Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 9 Share Posted November 9 I don't have Megasquirt but I know a little bit about EFI. Don't the MS data tables show injector open time? Duration? If open time isn't at 100% then it's not the injectors, it's MS not commanding them to stay open longer to provide more fuel. If they are at 100% then increasing fuel pressure should increase their flow rates. Sometimes on problems like yours it helps to break things down to the smallest elements. Analyze each step. What should happen versus what did happen. Quote Link to comment Share on other sites More sharing options...
MerloZ Posted November 11 Author Share Posted November 11 Sounds like something tunerstudio can read on the megasquirt but I'm not exactly sure what I'm looking for. I know I have injector pulse width in milliseconds as a gauge. I'll try to do some quick digging and maybe a data log to see if the injectors flatten out on a graph or something. I wish I had the time to dig into this like I did when I was 16. Quote Link to comment Share on other sites More sharing options...
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