Rich bog during acceleration
G'day Everyone. I'm new to the sight but I was hopping someone might be able to provide me with some advice for tuning my system.
I have a GoStreet 400 on a 206 cid inline six. The engine has a good flowing head and manifold, 10.53:1 compression ratio, 224 @ 50 cam with .490 thou lift and I'm running a HEI distributor. I estimate the motor is good for around 200 hp at 5800 rpm and is very quick revving. It has between 7 - 9 Hg of vacuum at idle and I am using Cam setting 2. I'm also using the default V6 file as the basis for my tune. The engine is in a 2300 lbs (1150kg) car with a manual gearbox and a 3.36:1 final drive ratio.
The main problem that I'm having is that I can't seem to tune out the rich bog when I roll into the throttle. The engine goes massively rich (10.2 AFR) and then starts misfire and bog down as it drowns in fuel. Eventually it will pull itself out of the bog (generally after I've eased off the throttle a bit) and get back into a usable AFR then pull hard.
I've tried every adjustment I can in my ACCEL Pump setting from fully into the positive +80 ish to fully into the negative -80 ish and none of it seems to make a difference.
I've also tried adjusting the fuel learn setting to give the system more scope to adjust itself but I just can't seem to stop if from bogging down.
The other issue I'm having is that I can't seem to Read to ECU. When ever I try to save my setting it gets to 98% and then say "ECU Response Error"
Can anyone help?
Cheers
Glad you are here. Let's see what we can do.
With that vacuum, I would try Cam 3, and reset your Learns. This will mess with your tuning tweaks, but what we want to see is a better AFR Learn value. This will take some time to relearn, but I would bet you are at the limits of the cam table you are on now. AFR Learn values in between +/- 20 are good.
Sharing a datalog would tell us more. If you would, share one with Dropbox. 30 second idle log at temp.
I would contact Fitech on the Tune Saving issue. Let us know what they say.
Thanks for the response Austin, I did try it on Cam 3 for a while but it didn't seem to make much difference. Maybe I didn't give it enough of a chance. It's also coming into winter down here in the land of Oz and I'm struggling to get the thing up to operating temp.
I don't know enough about the way the system works but I would have thought that if anything running on Cam 2 would cause me to have problems with lean running. Wont going to a more aggressive Cam map add more fuel across the range?
My AFR's a at cruise and idle are fine.
I will try it again on Cam3 though. I've been having issues with my hand held controller as well, so far I haven't been able to save a datalog yet.. (ill keep trying though)
I'm rapidly getting to the point of giving up on this thing and putting a Carb on it. It'd be a shame .. it promised so much but so far has been very disappointing. Unfortunately for me there is very little information out there for people who are not running the usual 350 cid V8 that the system was designed around.
Cheers
Your issues dont really jave anything to do with your engine. Just need a little more understanding of the system.
1. If engine is up to temp, but handheld says it's not, the CTS is bad. Fitech remedied this with a calibration menu, but I recommend you buy a new sensor. You can find a Delco part number and a link to it in the Parts and Accessories topic.
2. Anything below 10 on vacuum, is usually cam 3. I'm not concerned with your AFR. I am concerned with your AFR Learn.
3. Datalog problem. Plug the handheld into your PC, go to Log File and delete Dashboard File. Do this everytime you want to delete logs. This should get the issue resolved. Also always shut down engine and wait for ECU to power down before unplugging the handheld.
We will get you on the right track. I know you are frustrated. Been there. Why I started this site. Give it a chance. Knock out one issue at a time.
Cheers for the feedback mate.. I'll keep persevering with it. I've changed it over to Cam 3 and reset the saved fuel learn data.
I think my temp sensor is ok, the hand held unit reads roughly the same as the in dash temp guage.
I'll try and get some miles on it over the next few days to give it a chance to do it's thing.
I've been trying to fix the rich bog by taking fuel out of the 65 and 170f, Accel and fast Accel fields. Am I perhaps going about it the wrong way. Should I be adding fuel to try and stop if from over correcting?
Yes, adjust for first condition, not the correction. These things are designed with a lot of correction. When you throttle, if it gies lean then rich, add fuel. If it gies rich then lean, subtract fuel. The first condition will only last for a brief moment....
Cool.. I'm hoping to get some miles on it this weekend. I've already added some fuel to the Accel fields and it does seem better. Still bogging on acceleration but better than it was.. I'll give it a chance to do some learning then I'll start adding some more fuel. Hopefully I'm on the right track now.
This forum has been excellent thanks. I've been doing some surfing and have been able to find some pretty good answers to some of the other minor issues that I'm having. like:
Hard to start when cold.
Hanging idle
However I stall can't save my data logs and I can't read my calibrations to the ECU. (it gets to 98% and then says "ECU Response Error") I've sent an email to the Fitech support email address several days ago but they haven't responded.
Have we updated your software. May solve the Tune save issue. As for datalog. Hook handheld to the PC. Open Log Folder. Delete dashboard folder. This should fix that issue. Simply deleting the logs doesn't work for some reason. You must delete the Folder.
Hanging idle is IAC loop down adjustment. Hard start!!!! That is on you. Everybody has this issue. Takes time and patience to get your combination correct. Even Jeremy, lead engineer and owner of Fitech, hates it. His solution? Go multi port!!!!😂
Yeah I'm happy that the Idle and hard start issues will get sorted in due course. I'm more focused on the rich bog issue at the moment. I'll worry about the other tuning issues later.
In answer to your question, No, I've never updated my software.
Also, there is no "Log" folder when I hook my handheld to the PC.
When I connect and open "Mass USB Storage" I can see 7 folders plus the handheld instruction manual. The seven folders are:
cal_file
cal_info
hex_file
map_file
monitor_info
sys_bin
Trouble_code_map
None of these folder contains a "Log" or "Dashboard" folder