something was very wrong with that tune (or my car), but in a panick and stopped in the middle turn lane to re-install the old tune i forgot to save the log file. it was fine until i gave it 1/4 throttle then it acted like it was stalling out running on half the cylinders. i shut it off in neutral and rolled to a stop. the only thing i changed was the trans abuse, and all the trans settings....i left those the same as the base tuneOriginally Posted by SiriusC1024
Last edited by JR92RS; 05-09-2023 at 02:24 PM.
You don't have to saved the log. If you stopped the scan, it saves automatically.
it might have been this one but i cant be sure
I'm confused. You changed everything except those settings? Or you only changed those settings?
In the log you posted there's a few WOT runs, but the car keeps pulling. I see the KR. I don't see the 1/4 throttle stall event.
i removed all the transmission changes, and trans abuse changes from your tune then installed all the others as you had them. i might have overwritten it...ill look again. i found it, you can see toward the end where i shut the car off and had to write the old tune back in.
ps. it cool the scanner saved it automatically under settings....i didn't know that before
See that's weird. Car was running fine (except for KR) then suddenly the O2 sensors trend opposite. B1S1 goes rich, B2S1 lean, and while injector duty cycle stays the same for both banks. Fuel trims aren't working here.
im not sure if it was your tune at all,
i did a front brake job tonight, then went to pull it out of the garage under the paid tune she fell on her face again feeling like she was only running on half the cylinders... i barely got her parked. i checked the fuel pressure and she was @45psi...so i hit the key twice trying to prime her and she made it up to 48-50psi before very slowly leaking down (maybe a pound every 45seconds). so i pulled all the spark plugs and put an endoscope down each cylinder looking for a pool of fuel (stuck open injector) no such animal found,
but i did see freakin carbon buildup already on the pistons (does this mean she has been running rich?) so tomorrow i'll contact aeromotive and find out what their 200lph pump should ohm out @, then check to see if i have a failed 2 month old pump, also the tuner looked at the log file and said my passenger side o2 sensor is bad.....would that explain why the o2's sometimes flat line or stop oscillating opposite of each other?
and do any of you agree with his assesment of the o2 sensor failure from what you see in that log?
attaching a pic of piston to find out if that is normal or rich running
also if i'm buying o2 sensors anyway can the 3rd gen ecm's read wideband o2 sensors and could those be run full time?
Last edited by JR92RS; 05-09-2023 at 09:52 PM.
Ok glad you found the culprit. I've been going over the tune wondering wtf happened.
I was wondering about the O2 being bad. Didn't see any codes, even pending, but it still might not have had enough time to register. Get a new pair of Denso's in the front. They seem more resilient to the extra fuel in the exhaust stream due to overlap of cammed cars.
The wideband will not interface with the PCM. It runs as a standalone, but you can get telemetry from it to show up in your logs. They're a great tool. AEM is a good unit. I get telemetry off the serial port and adapt it to USB.
That fuel pressure has to be 58psi by the way. I see you have some ideas about how to go about fixing it.
Check to make sure that the return line from your regulator is dumping straight into the tank without obstruction. I'm not sure about your 3rd gen Fbody tank, but some cars have a fuel pressure regulator in the tank on the return line.
May consider a digital fuel pressure gauge and transducer in addition to a wideband.
That carbon buildup will clear up some once you dial in VE to get fueling correct. One trick is to run marine grade TC-W3 2-stroke oil in the gas at a ratio of 1 ounce per 5 gallons (640:1). Sounds ridiculous at first, but it keeps the carbon cleaned off as well as lubricating the upper cylinder and valve stems/seats. I always run it in mine. If you do it make sure TC-W3 rating. One thing to keep in mind is that heavy carbon like that might be a sign of poor fuel atomization, which will happen if your fuel pressure is low.
Last edited by SiriusC1024; 05-09-2023 at 11:17 PM.
yea it shouldn't take more than 30 minutes to repair, finished a trap door mod 3 months ago.....10 -12 cap screws and i have the pump out, and the aeromotive hanger has no regulator on it. i have a fuel gauge tucked under the car....easy enough to look at
i put in a set of denzo o2 sensors today but my problem persists, can someone look at the log files and tell me if the o2 sensor problem is resolved, i have attached the 1st log that the tuner said o2 on passenger side was bad, and the log from today after the new o2's were installed.
(disregard the flat spot i saw smoke and thought i might have wires burning, i forgot about the penetrating oil i shot on the o2's to get them out) most of the activity in question is at the end of the log.
and i watched the fuel pressure while it was idleing with no problems, but the pressure was holding steady at 58 psi, gonna head down in a minute and stay under car waiting for it to act up so i can see the pressure at the moment she goes all wonky
Last edited by JR92RS; 05-10-2023 at 03:08 PM.
Which tune is applied at 'new o2 senors' log?
the one i had done local on the dyno, i still haven't figured out what's going on.....fuel is fine i watched the gauge today while running fine, and while it was acting up.....i never lost fuel pressure, the local tuner seems to think i have problem in my harness somewhere....i played with all the ends while running and couldn't pin point any bad spots
No I don't think it's wiring. The problem is pretty consistent - throttle rapidly closing after high angles stalls the engine when returning to idle. You should start logging IAC counts.
How come the tuner disabled Throttle Cracker?
Try:
Engine>Idle>Airflow>Throttle Cracker
Enable Speed = 3
Disable Speed = 2
did it look like the o2's were working correctly in the second log?, i will try that and i don't know why i image because it is another table that will affect his dialed in ve table.....would it not?
Last edited by JR92RS; 05-11-2023 at 07:30 AM.
i don't see that one, unless it's called something else
how do i set that up in scanner?
i also had some dtc codes that would pop up when the engine acts all wonky....i will get a pic of what those were later this morning
Last edited by JR92RS; 05-11-2023 at 07:31 AM.
Should have been the first step.
i was hoping the log saved them but that doesn't appear to be the case, and i can't remember what they were exactly.
one was some sort of injector circuit malfunction (didn't point to any particular one), another was mass air volume to high (i think) (which doesn't make sense since the maf is disabled under the sd tune)
Last edited by JR92RS; 05-11-2023 at 07:48 AM.
the only thing that has changed in the last month that could possibly affect the harness was installing the trak spec hood louvers, and it raining on the engine.
so today i will brake clean each pigtail and put die electric grease on each one to see if that could be it.
"injector circuit malfunction" sounds like something outside of the tune and needs to be addressed first.
That code isn't good. You're having a hell of a time with this, feel for you.
Hopefully it's just water. Maybe poor connection at the injector plug since they're aftermarket. If it's not wiring it'll be complicated.
Injector circuit malfunction could be one of those injectors already failing. Those Accels are 12ohm injectors, and that's GM factory spec. They are also R-C snubbed to protect the ECU. Technically the injectors should run fine, but can never be certain with aftermarket solutions. An intermittent open or short circuit caused by a failing injector can be really hard to spot because it's difficult to replicate the failure. Hopefully whoever you got those off of has a good warranty/return policy.
Last edited by SiriusC1024; 05-11-2023 at 10:12 AM.
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