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Running lean under boost
Would like to know if anyone else with a boosted Z has experienced the car running lean under boost, and what their issue was and how they fixed it please?
Only just had my TT build finished up and currently being remote tuned by Seb, but ran into this problem of the car going lean when I tried the WOT pulls. AAM Competition RHD TT Kit ID1050x Walbro 460 CJM S1.E System Fuel Pump Relay Kit Running e85 Below is part of am Ecutek log when I tried the pull: https://s6.postimg.cc/9ylgw6lqp/rece...0888210554.png My workshop has looked for possible fuel leaks and pump voltage and that seems to be all ok. So they assumed my Aero340 pump before was too small, so they changed the Aero340 to a Walbro 460 and that instantly made the car feel better and more responsive but the lean issue was still there although not as bad as before the new pump. Seb has tried to force more fuel in the tune which also helped but as you can see from the graph it still progressivly gets more lean under the load as it increases. My fuel pressure on idle is @42 psi, I think that is with the vaccum/boost hose connected, not sure if it should be higher? Atm I am waiting till Monday to get it onto a dyno so we can check the fuel pressure under load, as suggested by Seb. Has anyone had this problem before please share you experience with me, thank you! |
Looks like you don't have enough injector. Most folks get at least IDA 1300cc injectors for
for E85. I am using IDA1700cc for my build. Go through the trouble shooting process and see what happening with the fuel pressure. |
Did you get the fuel pressure gauge with the CJ Motorsports fuel system? It shouldn't take but a pull or two on the dyno if you do. Then you will know.
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If you have the return kit you should be able to increase fuel pressure under boost ... if it was tuned correctly and started doing this you may have a vacuum leak on the fuel pressure regulator ... my fuel pressure at idle is 52 but I also have different injectors
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Ideal should be between 50-55, might have a small leak in your fuel
Lines. |
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Also interestingly, on another log I took the other night of a semi-pull in 2nd gear, 'Injectory Duty Bank 1' dropped from 50 to almost 0 momentarily. But I think that may be another issue altogether that Seb has said may be a failsafe map dropping the throttle, which he has adjusted and sent another tune through, I have not tested that new tune but will do tonight. See below: https://s6.postimg.cc/ldhy0zdkh/rece...1787740464.png Quote:
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The workshop it was at, said they done a leak test accross the fuel system, tensioned all lines and could not find any faults? |
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May be different with e85 tho ... I’m speaking from 93 oct settings .... but either way idle should be 52 ish and it should increase with boost |
Just got Sebs latest revision and my car basically resulted in the same logs where under WOT my AFR will start rich but then increase leaner under the load. But it did get rid of that sudden injector duty drop from bank 1.
https://s6.postimg.cc/727mn47gh/Inj03.png |
You'll find it. Something wonky is going on.
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I am wondering if I can adjust the pressure by increasing it by an increment of 5psi and see if that will help stop the leaning out issue? Quote:
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Seb is the man, follow his lead.
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Is voltage suppose to drop in spikes?
Can anyone check out this graph and let me know if it is normal? https://s6.postimg.cc/prwecnxgx/20180723_164523.png |
Wow, it looks like you may have a bad cell in your battery. The voltage shouldn't drop like that. Bad batteries can cause some strange things.
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Could that be the reason I am going lean under boost? Maybe battery is not supplying pump with enough voltage?
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