How do you dyno tune without data logging?
How do you dyno tune without data logging?
Let me rephrase that I was not the one logging so none of the logs were kept. On the injectors I know they are rated for 58lbs at 4 bar. They are same injectors the 2014 gt500.
The tune has them scaled as around a 51lb@4 bar. If they are really 58lb that would make the fueling even richer. The calibration is from a 99 F-body MT. Is that what this is in or is it a transplant into something else?
I don't know why my tuner set them up like that. At 3 bar they are 52 lb injectors but gm runs 4 bar so it's 58 lb.
This set up is in my 1997 Nissan 240sx. But my whole setup from trans to wiring harness to pcm and o2 sensors are set up for 99 to 02 fbody.
I see more fuel pressure problems with transplants than any other problem. Also a little longer log with some mixed cruising, light acceleration and wot would help.
here is a longer log with 2 brand new o2 sensors. The o2 sensor MV are still low. It's weird because in some parts of the map it's showing lean like 100-200 mv but stft are still commanding negative fuel trims. Something is fishey. I need to get a wide band on here asap.
Well something is definetly not right. It's running stupid lean. It went up to 16:9 afr at WOT when the cut happens. But the ve map has a lot of fuel. I wonder what's the limit of the return less fuel system.
Don't know why you threw money away on 2 new O2 sensors. I said that wasn't your problem. Money would have been better spent on a FP tester with a long hose you could tape to the windshield. FP gauge mounted on the rail is pretty useless while driving the car. Are you sure you posted the tune file that is in the car while doing those logs? Remove the MAF PID from the table display so the timing histograms populate correctly. Remove some of the other unnecessary PIDs also. You don't need the crank and cam sensor PIDs or the Gen F term, burst knock. LTFTs are disabled. Remove the PIDs. You have TP in there twice. Add TPS voltage. Why for 1 1/2 seconds while at WOT do the rpms drop from 6200 to 4500 rpm? Do a longer WOT pull in a higher gear.
Originally Posted by 2xLS1
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I'm watching the fuel pressure from inside the car it's an automete pressure gauge so I know it's not dropping out. I thought I did mention earlier that the fuel pressure wasn't dropping out. I've never used hp tuners before so I don't know what I'm supposed to monitor. I was trying to watch anything and everything. I've been at this for 2 weeks straight and I'm just throwing money at it right now. I'm not the most educated person when it comes to the tuning the side but I built this whole car. ive been frustrated with this whole thing and thanks to you I feel like I'm closing in on the problem so thank you.
Now have you seen an issue with the return less system that uses the corvette fuel filter with the regulator built in mounted at the back of the car? It used to be mounted in the engine bay with my ls1 setup but that only made 462 hp. I moved to close to the gas tank and running about 5 feet of -6an line feeding the passenger side fuel rail first. It goes fuel pump into 5/16 metal fuel line into fuel filter into -6an hose to rails.
The more things you log the lower the resolution of the data. That's why I said to remove the unnecessary PIDs. Logging MAF when in SD skews the air flow data for the histogram. I'm not seeing a large increase in IPW with rpms but the WOT logs you post are so short it's hard to see what is really going on. Do a 3 or 4th gear WOT pull. I've seen stock F-body fuel systems support 450-465 rwhp. I've seen plenty of transplants with the vette fuel filter fuel system without this problem.
Ok I will thank you. My car makes 559 rwhp so I'm questioning if this fuel system set up can keep up. I'm scared to do a longer pull for fear of damaging engine. I'm surprised I have t damaged the engine yet but I've only done 2nd gear pulls and it spins the tires and hit the cut so quick that it's hard to see what's happening.
And that drop your seeing from 6200 to 4500 is the engine costing in gear after it hits the cut. It loses pedal and drops rpm until it stalls out.
Last edited by boback1; 01-20-2016 at 09:56 PM.
I bought another pcm from a 02 Camaro and started the tune from scratch. It still only revs to 6400 rpm but doesn't die out anymore. just backfires when it hits the cut. almost like its cutting spark. do these ecu usually cut spark instead of fuel for the limiter? my previous ls1 motor ( which was in this same car with the same ecu ) would rev to 7000 rpm no problem and have a soft rev limiter.
Last edited by boback1; 01-12-2017 at 07:08 AM. Reason: new info
bump edited last post with new info
Good chance its losing crank sensor sync at high rpm. Check the sensor gap to trigger wheel as well as the centerline position of the reluctor wheel to the center of the sensor. Quick and easy way it to remove sensor, apply a dollop of white lithium grease to the end of sensor and reinstall. Roll engine over by hand a bit and remove sensor straight out and view it. Most of the time its an issue Fore/aft from centerline.
i feel like i've checked that before but its been a year so i could be wrong . i've had logs in here when its happening. anything i can log to try and see that before i pull the header and starter to do it ?
Sorry to bring this back from the dead, but I am having literally the same issue that you're describing... Setup is a LQ9 block 414 stroker. I didn't change the reluctor or do anything with converting to to Gen 4 stuff with exception to Ls3 coils. I was running factory truck coils that came with the truck and never changed the dwell in the tune until recently. I don't believe the issue has to do with the dwell settings in the tune. I'm running a 1 bar SD os. My thoughts are potentially a bad coil or ignition cut out at high rpm or fuel pressure drop at high rpm. I had a FP sensor wired into the egr hat I was logging awhile back, but now is just wired to the gauge on the pillar... It's hard to tell if the FP dips at the time it backfires. But once it does, I'm forced to cycle the ignition to get it to run again. If I don't cycle the key, the truck will continue to pop and backfire as it decels to a stop and will get worse if I press on the throttle. If I let it coast down without turning the key off, it'll die on its own every time. After a restart, it drives fine, like nothing ever happened(as long as i don't hit WOT or high rpm).
The injectors I'm running are Bosch ev6 mustang injectors. 4 bar 55lb. Running a return setup with 044 pump in the large HD truck factory tank and bucket. -8an feed and -6an return.
I haven't been able to confirm if the fuel pressure is dipping, but the WB is spiking to the lean side right when the backfire happens. The inj duty cycle is upper 40% and the pcm is commanding PE fueling at the time of the lean spike. So Hopefully this is enough info to direct you to the source of your issue. I believe mine is likely fuel pressure related, but I'm not 100% sure yet. Probably about 97% =) though.
Another thing I noticed is that my EVAP purge goes from 100% and starts to drop down to below 40% whenever i go WOT. This might be irelivant to the situation, but the reason I bring this up is because the solenoid is unplugged electrically. Is this normal?
Last edited by chrisxiv; 10-25-2018 at 09:58 AM.
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