Not sure if anyone could help, but I'm running lean with a +10% to +12% LTFT. Not vacuum leaks (thoroughly tested), and I just rebuilt the motor this past summer (stock z3 with some race bearings, honed cyls, head completely redone, rings (gapped slightly looser end for boost in mind), ALL new gaskets, etc). No mods that could possibly affect AFR since all external engine parts are the same as before the engine build, and I didn't have this issue then. What I'm left suspecting is the new donut gasket I put on, tightened to the point where the bolts are about to snap (factory manifold, just a catback). Is there any way to tell from these datalogs if that's what's going on? Zero knocks.
CALIBRATION BASED ON "Completely stock, tuned" BASEMAP
never had a problem with it before the rebuild
Exhaust Leak Upstream?
Exhaust Leak Upstream?
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- cali.fpcal
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- some_pulls_uphill.fpdl
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- normal_accel.fpdl
- (530.09 KiB) Downloaded 98 times
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- looks_better_but_same_calibration.fpdl
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- afr_oscilates_a_ton_at_15%load.fpdl
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Re: Exhaust Leak Upstream?
Bump. Anyone? Lots of views and no replies. Fuel pressure is good, injector duty doesn't go over 80%. If I'm correct, AFR should not fluctuate this much and I'm running lean. Any help as to where to look first would be greatly appreciated!
Re: Exhaust Leak Upstream?
It's a possibility, but cannot be definitively determined from just a datalog.
Re: Exhaust Leak Upstream?
Do you think those numbers look unsafe to run on a daily for a few months? I want to wait until the spring but I could try to get new bolts at the suspected flange and see if i can get it tighter. I might also test my injectors but my car might be down for a while. This may be more of an 8th Civic question sorry.
Re: Exhaust Leak Upstream?
You may want to discuss the issue with a tuner as they may be able to help you pinpoint the issue. They will be able to tell you what is safest for your situation.