Lean condition--FAST

Heck no Bob, not at all. I was just trying to give you a feel for what my thought process was.

Remember though based on his starting TPS position of 24, none or very little of that 100% part he has is effective since the min. position is 24. Basically tps/acel is getting taken and read off the right half of the 2D.
 
But if the throttle isn't moving, then he gets no AE, so 100% of nothing is nothing. Or maybe I still don't understand what you are saying...

-Bob Cunningham
 
Correct, when the TPS does not see movement he does not see any AE, agreed. I'm not saying the AE map is causing his problem yet but the few times I have looked at his GTC file he changes it dramatically to try and compensate for the underlying problem. What my intent is, is to try and give soem thoughts on what the basics should look like on settings so he doesn't keep going in circles. I also thought it would make sense to verify that the TPS is sweeping as it should as he applys the gas.
 
Well one of my goal this morning with the Typhoon was to change my idle TPS and follow some of the recommended start points on page 1 for AE tables.

I changed and set the TPS to 14, changed the max idle for 15 and then changed the AE vs TPS table to the points recommended for starting.

I only had to tweak it up a bit but what a huge improvement in off idle and from mid range to WOT.

I just wanted to give thanks to those of you who are helping the rest of us learn around here. This has all been very helpful and I keep reading and learning.
 
Well I have been playing with this some more. I have enough miles on the motor that I have been doing some WOT pulls... the setting for acceleration seems to be perfect for WOT there is less than 1 degree of correction from the time I stab it all the way to 6000 RPM.

I still have a small part throttle off idel stumble. I can tell where it is occuring between the cells. Is there a general rule for how much of an offset between the cells there should be? For example if I have 60 in a cell, should the next cell Ideally be 68 max? I hope what I am asking makes sense. UP high in my tables where I am not at for tuning yet there are some big gaps... but the gaps down low seem to be small.

Also, not related to this topic but since I already have your attention.. is there a specific way to address deceleration? When I let off of the gas the thing goes pig rich... is this just inherent to the beast or is there something I am missing?
 
Well I'm by no means knowledgeable on this but I found that I was popping on decel. I richened the cells up until it stopped.

The cells are in the area of 80 and the AFR is about 11.5:1

BUT, having said that, the duty cycle is only about 2% so though it may be rich, I don't think there is a lot of fuel going in.

I assume that is OK. I'd sure like someone to tell me that was the right thing to do.
 
66, what I would do is this, look at that area onyour A/F map and make sure the value there is what makes sense. I can't really help you there much as to what is correct as this is a boosed application right, and I don't know if your beginning to build boost. But I suppose if you are building some boost than something like a 14.7 would NOT be correct and someting like a 12-13 might be closer. Not enough info right now to give you any guidance here though. At any rate that is the first thing I would confirm. Then I would mark the area you are having the stumble in and go out and verify when loading and holding the motor in those cell ranges the corrections factors are small and the VE values are correct at those points and above, below and next to that area as well. One thing you can do is set the values in those cell ranges maybe 5-8 percent richer than the correct values. So if the "correct" values are 60, 67, 74 or whatever set them at 65, 71, 77. That way the target will be a bit rich and in the few seconds, or less, it takes for the computer to catch it you will be able to drive through the lean area but the computer will compensate it back to where it needs to be if you are under steady state conditions in those cell ranges. That would be one thing to try, but not the best way to do it. I have found though that the mapping should not have BIG changes cell to cell and it is a much nicer map if fairly smooth. I have always worked with N/A mapping though and not boost.

Most likely though it is a AE adjustment that is needing just a touch of further refinement. If it is a delayed tip in I suspect the MAP AE correction needs to be increased. If it is basically right away the TPS is the first thing I would look at. I'd look at the AE Vs TPS position screen first and see where the TPS is working at when you are doing the tip in. If it is an area that you are taking some enrichment out raise the graph some and richen it up. If you have it at 100% and still have the problem you have to give it more "shot" in the AE Vs TPS Rate screen. That is where I would spend my time trying to tune this out.
 
Ok, thanks for the help.

I was tuning tonight.. finally got someone else to drive.. and if you are running WOT here say I just jab it from a roll it is fine.

If I have them roll into and don't get the throttle past maybe 25% that is when it stumbles.

I am going to go into the VE table and the A/F table and set it up to run a bit richer there as suggested and try it from there.

It was great having someone else drive.. we have it now set up for when you either jab it or just roll into it, 12 psi it is showing little correction on the way up and once it is to 12 psi, it on about 5-7 consecutive passes it stayed +/- 2.. so now it is time to start giving it a bit more boost.

Thanks for the tip... I will try what you have suggested and see how that works.

FYI - for the time being.. through the mid ranges when it is building boost I run it about 12:1 and when it is at boost I have it set at 11.8:1 for now. I may lean it up a bit later.. we will see.. running 20 degrees of timing with no knock.

Also for clarification for myself... once I have the VE set so that the correction is optimized.. if I want to run a different A/F all I have to do is adjust that table right? In theory no adjustment to the VE table is necessary? So right now at WOT it is set at 11.8 and when I want to run 12:1 I just change it right?
 
Guys I just make the power tour trip from Nashville- Memphis- Jackson-New Orleans. I had plenty time to tune and look at what is going on.

My tps is changing, it could have a bad spot, I did not check it with the vom. The stumble or miss or lean condition is at 28-31 tps position.

I interloped the cells and the 2000rpm cells take all the 02 correction i have in (25%) from 44- 75 kpa and the stumble is still there. I still get a backfire out the tb every now and then.

I changed the cells so there was no correction but the stumble was still there.

Do any of you think I should be richer than 13.0 at the 2000rpm area?I am going to change my A/F ratio to 12.0 in the 2000rpm cells and see what happens.


My AE seems to be good there is no stumble anywhere else.

I am not convinced it is not ignition related but----- Why would it only happen at 2000rpm and why during steady throttle and under acceleration as it goes through the 2000rpm cells but no where else.

The car ran great on the trip. I dialed in the ve tables real close above 2000rpm and added fuel for starting so the engine cranks real quick after the starter turns, cold or hot.

Keep asking questions we will solve this!!
 
On my car, or any car I can think of under those conditions, medium to light accel, 13:1 would be FAT (rich) and 12:1 would be what I call PIG FAT. So I'll be surprised as hell if that does anything. Long shot here, are you sure the valves are all adjusted properly? One time I had a situation where a motor had a slight miss at very light throttle and cruise. Valves were out of whack.

The other thing to try is while you are at this stumble/bad cell condition try changing the Injector opening time up to 1.3 or 1.4 and see what happens. Just for giggles.

Send me the latest GTC file you have and I'll take another look at it.
 
well I went in and bumped all the A/F in the idle area down to 13:1 and changed the bottom row to that as well. This seems to have cured the problem with the part throttle stumble all together. Seems to go between park and drive better too.. sometimes before it would stumble.

Now I have to go back in and lean up the tip in where I was trying to fix the stumble with that. Now it is so rich from idle that if you stomp it, it will nearly make the truck stall.

I am not sure if your problem is related to this or not. I had the entire lower row set at 14.5 and the mid range set at 13.5 .... since I lowered it all my symptoms are gone.

Just thought I would share my experience. I think I am really getting the tune right.
 
I checked my valves today and found nothing wrong. I also went in and put the VE numbers close to where they should be. I ran logs.
Rick, Bob and Chris I sent you a gct and new logs. The engine leaned out in the 2000rpm cells as usual with the lower numbers with the 02 correcting the max I had it set at. I don't know if the IAC would cause this problem but I would not close today and I took it out and cleaned it put it back in and end up unplugging it to get me home because it would open completely and stay there.

I will check for vacumm leaks tomorrow and turn of the 02. With no IAC and the wide ban off I will eliminate two sensors. So I will drive the car and see what it is like.

NOTE: The IAC was not the problem. On the way home I noticed the coolant temp was -6, so I checked the sensor and it was unplugged. IAC works aot better now. Imagine that I actually solved a problem!!!
 
Out of curiousity could I also have a copy of your GCT file and the log?

I am just curious to see it with the problems you are having versus what I was experiencing and fixed.

If not, ok, otherwise send them to nick.steffens@usionline.net

All in the process of learning.
 
Have you checked to make sure that you don't have any exhaust leaks? Those are notorious for sucking in air at only certain rpms, and fooling the O2 sensor so your tuning winds up with a "hole" in it where the afr isn't what you think it is. On the TR's a leak usually makes the idle blm go way up (ecm thinks it's lean) but the higher rpm/load cells are usually okay, but on one friend's car he was trying to make a chip and kept having to make the 2400 rpm pe-rpm cell way out of line with the rest of the table to get the O2's to be uniform, and then he had a big flat spot where the car would not spool. Fixed the leak, the O2's at 2400 changed a whole bunch (but the idle blm was normal the whole time), retuned the chip to get them back, and now it's great.
 
Nick, you have mail.

ijames, I have turned the closed loop off before and did that again this morning with the IAC unplugged and the stutter was still there. I watched the 02 while I drove and it was showing lean, over 15.9.

I am pulling the plugs today after I check for vacumm leaks to look at them.
 
Ricky,

You have your A/F table set up the same way I did... I am of course no expert, but I can tell you 95% that what I did fix your problem too.. it cannot hurt to try it.

Take you whole A/F table and do like I have suggested... I have attached it here.

Try it and see what you think.. this made it go away on my truck.

sampletable.gif


You are interpolating values from all the cells around it and for some reason those extremely high values in the lower part of the table and up a few cells were causing my problem.

Try and see. This is what jumped out at me as your logs and my original A/F table look nearly identical.

Play with it as you may be able to run it a bit leaner than what I have suggested... Mine is actually at 13.3 which is richer than I suggested but see what you think. If I run mine leaner than this at idle it will stall going between park and drive. Something I am working on.

Also.... I was looking at your AE VS TPS and your AE vs MAP and thinking they were really high compared to mine.. and I see why.

You have your TPS max for idle at 26... so per your previous post I see you are still at about 24 for idle. Well if you look there on the AE vs TPS position you are already only at 60% AE by the time you leave idle. So you have to jack the AE vs. TPS and the AE vs. Map table way up to compensate for this.

Just another suggestion, if anything here I am saying does not make sense or someone has other information, please don't hesitate to jump in, like I said I am pretty new to this but am learning.
 
Ricky et al,

Just wanted to see if there has been any change/discoveries (had to travel to South America for businees- a lot less glamourous than it sounds...)

-Bob C.

(p.s. I never got the new logs, but wasn't able to read the last ones)
 
Bob, I sent you mail from my laptop but it was returned. I might have put your email address in wrong. I had been emailing you from my desktop. I will send you the gct and logs.

I called accel tech about my tb and high tps% setting at idle. I will make some changes tonight to see if I can correct that.

I pulled my plugs and they look okay and checked my valves, looked at my timing map, I have 34* in at 2000rpm.

My wife is going to drive tonight and I am changing A/F ratio to 13.5 in that area. If that don't work I will make it fatter till it pucks fuel out the exhaust. I will post the results tonight or tomorrow morning
 
Guys, I went in and changed A/F ratio to 13.5 at idle to 2400 and from the bottom of the map to the top. I then went out on the interstate and ran 2000rpm with my wife driving. I started going up in VE to reduce 02 correction. Once I got that cell, think it was the 48 kpa I had her give it a little throttle and it stumbled pretty bad in the next cell so I did the same for the higher kpa cells at 2000rpm.

I ended up with high 80's in the 44 - 50 kpa cells then 100 -110 in the cells above that only in the 2000rpm area. I also ended up with alot more AE vs tps position and a ton more in the AE vs Map rate of change. I have the map AE going in real qiuck.

The engine ran good with no more stumble and the 02 is not adding alot of fuel in the 2000rpm cells. Once I got off the highway and pulled up to a light the engine was jumping around at idle in gear. The AE vs map rate was jumping in and making the engine fat and 02 was correcting so I had this tug-of-war going on. Should the map AE be coming in at idle in gear???? If not what could be the problem? Instead of taking out the Map AE I changed the "dMap noise threshold" up until it was not adding fuel at idle (30 instead of 7). I do have my throttle follower set at 12 with my idle tps at 23 or 24.

I drove the car to work this morning and it runs good, no stumble as the engine moves through the 2000rpm cells and no more steady 2000rpm stumble or spitting out the tb. I know the map looks weird compared to most and I don't understand why unless it has to do with my converter ( advertised 2500 stall with lock-up).

What does having to put the high VE numbers in to get the 13.5 A/F ratio tell me????

I still will need to look at AE fuel settings and figure out if I did right by using the dMap noise threshold to take out AE at idle.

I know I am closer to having a good tune. Keep giving feed back and thanks for the help.
 
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