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MadMaxHSV
August 17th, 2016, 07:51 AM
Not sure if it's the hotter than usual temps weather wise, i've got a new problem or changed something without realising it.
But...
When the car is warming up or sitting at cooler running temps ECT wise everythings fine. However when sitting for a while or the ECT temps get upto 100% my AFR's plummet and it sits idling at 10:1. STFT's swing full negative but have no effect. I've tried changing the charge temp bias even slashing the VE table but nothing I do effects the AFR which insists on sitting at 10:1. I'm running Siemens 60lb injectors so though it might be a low pulsewidth issue, so tried reducing the fuel pressure and compensating with the flow rates to try and up the pulsewidths but no luck.
I'm running out of ideas so would appreciate any new ones. Once the car's cooled right down everything's good again, but does almost seem to be a slowly degenerating problem after startup.
For background:
- supercharged LS2
- SD tune, no MAF.
- siemens 60lb injectors (scaled tables)
- boost referenced regulator (was set at 58psi base, tried 50 per above)

Attached the current tune and a recent log file showing warm startup (fuelling good), and eventual hot condition running super rich.

Any guidance much appreciated

Thanks

2009720098

joecar
August 17th, 2016, 10:16 AM
Is your FPR manifold-referenced...? If yes, then check the reference hose for liquid fuel (leaky FPR).

Are your injectors leaking when hot...?

MadMaxHSV
August 17th, 2016, 08:32 PM
Yes to the referenced FPR but no obvious signs of fuel in the vac line.
Leaking injectors may make more sense, just would have thought one or two might fail showing up on one bank rather than both going rich evenly. I've a set of LS9 injectors kicking around may throw them in to see how it reacts.
I verified the pressure at the rails and when hot (exhibiting the issue) the pressure is down by 3-4lbs which may point to injectors again...

Tre-Cool
August 17th, 2016, 08:54 PM
for it to over fuel you should be seeing pressure go up for it to increase the fueling by the amount you are. I dont see it being an injector issue myself.

Have you got another regulator you can swap in? if the reg is knackered its not bleeding back to your surge/tank setup.

Tune looks fine too

MadMaxHSV
August 17th, 2016, 09:04 PM
I've had issues (now resolved) where the return line at idle wasn't man enough to return enough fuel and the pressure would increase. But here i'm seeing lower pressure...
So either the injectors are blowing so much fuel it can't keep up (seems a unlikely) or maybe i've got a pump on the way out.

Regardless, in both cases this shouldn't explain an over fueling situation.

I do have another regulator also to try...

MadMaxHSV
August 23rd, 2016, 01:36 AM
Hi All, thanks for the inputs and in confirming the tune was not the culprit.
Turned out to be a bad regulator.

joecar
August 24th, 2016, 05:09 AM
Thanks for posting back.