Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 24

Thread: Going lean after start.

  1. #11

    Default

    Gregs69rs, Took your advice and made the changes you suggested. I think I may have made similar changes here already as there wasn't much difference to get close to Danny's numbers. I also messed with the IAC settings a little while in there, since I felt it was holding a fast idle too long once warm. Doesn't look like I had much startup enrichment at play, the lean waves seem to occur after it's been decayed out.

    Had trouble loading the new Config File from the SD card this time. Kept getting a "GCF product ID invalid" message on the hand held, so I loaded the new test config directly from the laptop. I made an idle log with that which behaved very strangely. If I just tickled the throttle slightly it would start to chug and send the AFR waving up repeatedly. I've attached that Config File and the datalog here if you're interested.

    I drove my regular config a bit more today and was quite happy with it, only noticing a few high AFR floats on my gauge occasionally, but nothing enough to create a driveability problem.
    Attached Files Attached Files

  2. #12

    Default

    Quote Originally Posted by AndyF View Post
    Both your Base Fuel Table and your Base Timing Table look wrong to me.
    What in particular do you see wrong with them?

  3. #13

    Default

    Something is way off with your Config File. It is saying Y-axis values are too low and using 0 to 0 instead. I'd go back and adjust your original file and make the changes there then reload. This may be why you're experiencing issues.

  4. #14

    Default

    OK. I know of another possible issue, but I don't have a great explanation as to why the "fix" works, but it works for me. If I crank the car in cold weather with just the key and don't touch the throttle after it has cranked, I would get a similar lean spike when the After Start Enrichment ends and it enters Closed Loop (runs fine during After Start Enrichment and Open Loop). Either it would stall or simply the CL Comp would jump way up due to the very lean reading. I have a big cam and think that when the car first starts up it has a bit of a misfire which shows up as lean. If I just blip the throttle one time I think it gets all cylinders firing and the CL Comp goes back to nearly 0 and the AFR is at target. I don't have this issue at all in warm weather.

    Probably a very specific issue to my setup, but maybe give it a try. Once the car starts, just give the throttle a blip to get the RPM above about 1500 and see what happens.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  5. #15

    Default

    Quote Originally Posted by thecowwatcher View Post
    Something is way off with your Config File. It is saying Y-axis values are too low and using 0 to 0 instead. I'd go back and adjust your original file and make the changes there then reload. This may be why you're experiencing issues.
    Hmm, I see what you mean. Something is messed up now for sure. Any changes I attempt to make to my Mar 22 20 Config File won't load back on to the handheld. I keep getting an error when I try to upload them to the ECU. Luckily I can still download and upload the original Config File though. None of the files appeared corrupt on my laptop but the Mar 22 20CE, but only after I opened the zipped version I attached here.

    Initially I just wanted to tweak what I had, but now I seem to have created some real problems for myself. I've attached another version of my original Config File now as a test, and another strange startup datalog I made with it.
    Attached Files Attached Files

  6. #16

    Default

    Quote Originally Posted by gregs69rs View Post
    OK. I know of another possible issue, but I don't have a great explanation as to why the "fix" works, but it works for me. If I crank the car in cold weather with just the key and don't touch the throttle after it has cranked, I would get a similar lean spike when the After Start Enrichment ends and it enters Closed Loop (runs fine during After Start Enrichment and Open Loop). Either it would stall or simply the CL Comp would jump way up due to the very lean reading. I have a big cam and think that when the car first starts up it has a bit of a misfire which shows up as lean. If I just blip the throttle one time I think it gets all cylinders firing and the CL Comp goes back to nearly 0 and the AFR is at target. I don't have this issue at all in warm weather.

    Probably a very specific issue to my setup, but maybe give it a try. Once the car starts, just give the throttle a blip to get the RPM above about 1500 and see what happens.
    Yeah, I kinda have the same thing which bugs me. My setup is 467 with 240°/246° @ .050 cam. Hot idle is around 900 RPM. And cold start only manages like 1100 ish cold (50°F). If the ICF would have been larger we could have set it to start at a higher RPM (IAC parked) and let it decay, and that would probably make all cylinders get going so the AFR reading would be correct.

    What I'm chasing now in this case is the perfect After Start Enrichment % and Decay Rate. Along with Coolant Temperature Enrichment and AFR Offset. Right now I'm at the point were when it first starts, it seems to fire on all 8, but it's really delicate on the AFR before I start to misfire on 1 or 2 cylinders. Then throws off the AFR reading and you have to feather the throttle to get them back. Or wait around a minute for them to settle back in. Getting closer and closer it to making it cold start like I want it.

  7. #17

    Default

    Quote Originally Posted by 78 C10 View Post
    Hmm, I see what you mean. Something is messed up now for sure. Any changes I attempt to make to my Mar 22 20 Config File won't load back on to the handheld. I keep getting an error when I try to upload them to the ECU. Luckily I can still download and upload the original Config File though. None of the files appeared corrupt on my laptop but the Mar 22 20CE, but only after I opened the zipped version I attached here.

    Initially I just wanted to tweak what I had, but now I seem to have created some real problems for myself. I've attached another version of my original Config File now as a test, and another strange startup datalog I made with it.
    I'm just now seeing this. I'll review the Config File and datalog and post an update.

    Update: Still odd that after a 34 second datalog your CTS didn't move once. It's either really cold or you have a very efficient cooling system. Either way I don't think your engine wants to idle at 600. I'd still step it up to at the very least 700 RPM and simplify your Base Timing and Target AFR tables. Set all of your Target AFR to 14.0 and your Base Timing table to 25° and we can troubleshoot the cold starts. Also, after the engine has set all night check the ambient air temperature with the CTS before you start it. If it's 65°F out and your CTS is reads 100°F then there's the issue.
    Last edited by thecowwatcher; 04-01-2020 at 06:58 PM.

  8. #18

    Default

    I've played around a lot in the last week or so. Solved the issue with my Config Files getting corrupted and not loading by clearing the SD card and reinstalling all the firmware. Happened again yesterday though, so I went through all that once more. Maybe I've got an SD card going bad. I'm trying to get comfortable with using the USB direct to my laptop to avoid that link now.

    Since the last datalog and Config File posted I've simplified my timing table some to be more conventional. Also changed all the IAC settings to be similar to a range Danny posted that I stumbled upon somewhere. Fiddled with the Cranking Fuel and other starting tables as well. I'm happy enough with the starting side of things for now.

    Still getting lean waves at idle and low speed driving that are my new focus. Read some stuff about TPS vs AE Blanking values that may apply, but haven't seen much effect from changing that. I've got this at 13 now which may have helped a little. My plan is to drive it as is a few more days then Transfer Learning To Base again and smooth the Fuel Graph and see where I'm at.

    Regarding the CTS, I still don't believe there's an issue. I'm in south Florida and the truck sits in the garage overnight and stays pretty warm. Around 100°F is what it reads on the typical morning now with IAT around 80°F. Maybe it reads a little high, but it doesn't seem to stick there.

  9. #19

    Default

    I have a 700R4 trans and experienced lean spikes while shifting. I have my AE vs TPS RoC at 5.9 and that seemed to have taken the big spike away. Don't be afraid to make large changes to see how it reacts. Keep dialing in the Cold Starts and reviewing the Learn Table and datalogs. I am working on tune adjustment 51 right now, yes that's 51 times I've made adjustments to my Config File. I review it quite often to dial it in just so I'm that much more comfortable with driving it.

  10. #20

    Default

    Quote Originally Posted by 78 C10 View Post
    Regarding the CTS, I still don't believe there's an issue. I'm in south Florida and the truck sits in the garage overnight and stays pretty warm. Around 100°F is what it reads on the typical morning now with IAT around 80°F. Maybe it reads a little high, but it doesn't seem to stick there.
    When the truck sits for 12-24 hours MAT & CTS should read fairly the same. The CTS that comes with the kit often shows higher temperature then what it really is when cold. And to cold when it's hot. Had the same issue with mine, and lot of others in the forum here as well. I replaced mine with one from ACDelco, Summit Racing website is down right now so I can't get you the part number.

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us