Slight surge under light throttle
03-19-2012, 10:37 PM
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Slight surge under light throttle Car is mechanically sound, no leaks. Runs good only problem is there is a slight surge around the 15mph to the 40 mph range. By slight surge I mean the rpms go up and down maybe 50. Nothing much, but it is enough to just notice it. I am sure it is something in my tune. Where should I start looking? The VE, MAF, and RAF is all dialed in pretty close.
03-26-2012, 10:06 PM
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The RPM is right around 1400-1800. No clue if the converter is locked. Want to say yes but not totally sure.
The default config will work with it. I dont have my wide band hooked for this since I dont think its reading right.
The default config will work with it. I dont have my wide band hooked for this since I dont think its reading right.
03-27-2012, 08:58 AM
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In the area of frame 1860. Tps is a steady 4, rpm's move around 100 up and down. Not sure I this is just what a cam does at ligh throttle or if it should be nice and smooth.
Then from frame 2785 till the end you see 0 tps but my idle is at 950-1100 making the car cruise around the neighborhood.
I did subtract 3 degrees of timing throughout the whole light throttle area after I read too much timing can cause that surge affect. Taking the timing out did not do anything.
Then from frame 2785 till the end you see 0 tps but my idle is at 950-1100 making the car cruise around the neighborhood.
I did subtract 3 degrees of timing throughout the whole light throttle area after I read too much timing can cause that surge affect. Taking the timing out did not do anything.
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03-27-2012, 09:15 AM
#8
I just had a quick look at the surge. -3* is nothing depending on your combination. I would try -10 or -15 maybe even more just in the area of the surge to see if it helps.
In the area of frame 1860. Tps is a steady 4, rpm's move around 100 up and down. Not sure I this is just what a cam does at ligh throttle or if it should be nice and smooth.
Then from frame 2785 till the end you see 0 tps but my idle is at 950-1100 making the car cruise around the neighborhood.
I did subtract 3 degrees of timing throughout the whole light throttle area after I read too much timing can cause that surge affect. Taking the timing out did not do anything.
Then from frame 2785 till the end you see 0 tps but my idle is at 950-1100 making the car cruise around the neighborhood.
I did subtract 3 degrees of timing throughout the whole light throttle area after I read too much timing can cause that surge affect. Taking the timing out did not do anything.
03-27-2012, 09:22 AM
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Thanks guys. SE, I was under the impression I should decrease the throttle cracker to lower the idle cruise, but you are saying to increase the numbers there?
And thanks CTD, I will try pulling another 7 out in that range to see if it makes a difference. My mods/set up is in my sig. Will give It a try. Wanna get this tuned as close as I can before I hit the dyno. Then I can see how jacked if any, my wide band is.
And thanks CTD, I will try pulling another 7 out in that range to see if it makes a difference. My mods/set up is in my sig. Will give It a try. Wanna get this tuned as close as I can before I hit the dyno. Then I can see how jacked if any, my wide band is.
03-27-2012, 09:38 AM
#12
Thanks guys. SE, I was under the impression I should decrease the throttle cracker to lower the idle cruise, but you are saying to increase the numbers there?
And thanks CTD, I will try pulling another 7 out in that range to see if it makes a difference. My mods/set up is in my sig. Will give It a try. Wanna get this tuned as close as I can before I hit the dyno. Then I can see how jacked if any, my wide band is.
And thanks CTD, I will try pulling another 7 out in that range to see if it makes a difference. My mods/set up is in my sig. Will give It a try. Wanna get this tuned as close as I can before I hit the dyno. Then I can see how jacked if any, my wide band is.
very small amounts of change....not big #'s...
your cracker is active when you are cruising down the road and above the MPH value set to enable it.
with way too much it can cause the "self driving effect" briefly, but if you have it that high, then you are really doing something wrong to begin with..
(and I'm referring to Follower/cracker as they are labeled in HP Tuners... IIRC, they are labeled opposite in EFI Live...its not right or wrong, its just terminology...)
your Running Idle Airflow is your base # that all Idle is based on...
then the throttle cracker only works when your throttle is open, once you let off it decays to 0 almost immediately
the throttle follower does a similar thing except for it is to add to your Idle airflow for when you let off the throttle to bring the RPM's down smoother so that your pcm can catch idle properly and not "Dip" or "Stall" from not being able to keep up with the speed of the rpm decrease.
you can log RMP/MPH/TPS/RAF/STIT/STLT and the Throttle Follower/Cracker and you can see how the follower/cracker react and how fast they decay to understand that they do not cause idle push/self driving stuff to happen...
03-27-2012, 10:40 PM
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well I added 30% from 400-1200 in the throttle cracker airflow and still nothing different. Has the same surge as before. Keep adding here or is there a different table I should be looking at? The attached log at frame 1500 is the area its doing it at.
03-28-2012, 11:45 AM
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Sorry I missed those but here is the log with it on a warm start up. This log has the only 3 problems I have all logged in the one tune. It
1. Flairs up to 1500 rpms for a few seconds then drops to 400 is then recovers to a good idle
2. Surge starts around frame 2150
3. Frame 2613 starts the 0 tps cruise effect. it starts to increase my speed making it idle around 1100ish and brings the speed from 12 upto 16mph. so not only is it a cruise but and actual increase at 0 throttle.
All in all this car runs good now. If I could figure these out it would run GREAT!
1. Flairs up to 1500 rpms for a few seconds then drops to 400 is then recovers to a good idle
2. Surge starts around frame 2150
3. Frame 2613 starts the 0 tps cruise effect. it starts to increase my speed making it idle around 1100ish and brings the speed from 12 upto 16mph. so not only is it a cruise but and actual increase at 0 throttle.
All in all this car runs good now. If I could figure these out it would run GREAT!
03-28-2012, 11:55 AM
#16
your idle airflow is set too high...the log is pulling 2g of LTIT and STIT air total(look at it in grams instead of lbs and you can see better details in idle airflow..)
that would be why you get a cruise effect and possibly the flare up as well..
you need to lower the Running Idle Airflow table
the fact that the car see's knock retard at startup tells me that you need more timing pulled from the start-up flare table...
try just making it take away an additional 50% of spark
I cant open the tune file from a previous post...
It gives me a parsing error, I can only guess that maybe you are using the beta? and I am not right now due to some bugs that were driving me nuts.
also, your timing jumps around too much when you are getting your "cam buck"
smooth out the timing table and a lot of that will go away and then we can determine if its just a poor spark table or airflow or both
that would be why you get a cruise effect and possibly the flare up as well..
you need to lower the Running Idle Airflow table
the fact that the car see's knock retard at startup tells me that you need more timing pulled from the start-up flare table...
try just making it take away an additional 50% of spark
I cant open the tune file from a previous post...
It gives me a parsing error, I can only guess that maybe you are using the beta? and I am not right now due to some bugs that were driving me nuts.
also, your timing jumps around too much when you are getting your "cam buck"
smooth out the timing table and a lot of that will go away and then we can determine if its just a poor spark table or airflow or both
03-28-2012, 02:08 PM
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well I did all you said and the cruise is gone but surge sill there and man does it surge high as crap at start up now. Jumps to 2200 rpm's then drops until it stalls. need to give it gas to keep it running. I guess I will keep playing with the timing a little to see what it likes. I do believe my RAF needs to be lower, its just the car runs like crap when I lower it. What else can be adjusted to off set the going lower?
I am running BETA version.
I am running BETA version.
Last edited by marthastewart; 03-28-2012 at 09:00 PM.
03-29-2012, 08:55 AM
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Well I loaded the last decent running tune in and smoothed the crap outta the timing tables. I lowered the RAF a little. Still surging, however the cruise has going for the most part.
03-30-2012, 09:45 PM
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Well no surge!! Not sure what it is though. I noticed it was gone when I loaded an old tune that was set up to dial the MAF in. That old tune has all the common things you do for the MAF tune but has my updated tune with the exception of the new tranny tune. So this surge is caused by the
1. tranny
2. Closed loop
Not sure yet.
1. tranny
2. Closed loop
Not sure yet.
03-30-2012, 10:38 PM
#20
Well no surge!! Not sure what it is though. I noticed it was gone when I loaded an old tune that was set up to dial the MAF in. That old tune has all the common things you do for the MAF tune but has my updated tune with the exception of the new tranny tune. So this surge is caused by the
1. tranny
2. Closed loop
Not sure yet.
1. tranny
2. Closed loop
Not sure yet.
something in your old tune is different... that difference is what causes the surge
airflow or fuel related or a combo of both...