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So I've gotten my IAC counts and some other things figured out. Car is now running much better.
The issue Im running into now seems pretty simple but Im not sure where to look to fix it.
If Im rolling down the road, I can put it in neutral and the engine will smoothly drop to idle speed and stay there. No big deal. I can leave it in neutral and slow down and it's fine, but as soon as I roll to a complete stop, it drops about 200-300 RPMs and nearly stalls. Then it recovers and is fine again. Seems simple since it idles more or less where it should while rolling and while in a steady state idling in place situation, it's just after rolling to a stop it does this. I know there's some kind of idle-vehicle speed threshold setting, and Im guessing that has something to do with it.
I'm having an issue with hot restarts.
Pretty much if I shut off the car when it's something around 220F and come back 20 or 30min later, the car acts like it's flooding.
Cold starts are fine...
Starting the car while watching with a wideband O2, it shows a pretty rich fuel mixture and it runs a little rough for a bit, sometimes stalling.
Sometimes I need to crank for a while, flooring the pedal in hopes of clearing the flood.
I'm using most of the values from the 3001 bin..
Details that might matter, CFI injection, renegade intake that's been ported slightly, edlebrock heads (70cc), aremotive fpr with the vacuum reference connected to the intake, and 80lb injectors.
long tube Headers, dual 3in exhaust, 84 vette.
One thing I have not done, was to check the cts at key on...
Increase the cranking AFR at the engine temperature where this occurs. Can also reduce the choke AFR in the same temperature area. Choke is really after-start fuel that is added for a short period of time.
Doesn’t appear to show any knock – so I’m not sure what’s happening.
Notice how this happens as RPM's reach upwards of 5700-RPM. You will see your engine vacuum reach 7", when it was averaging less than that at lower RPM's at wide open throttle. It jumps from 5 to 6" to 7" when RPM's increase, and depending on how your Main Table is set, it appears you need to make a few adjustments in that table to compensate for the increased engine vacuum at higher RPM's. How is your air intake? Is it adequate in terms of the needed volume as the RPM's increase?
Notice how this happens as RPM's reach upwards of 5700-RPM. You will see your engine vacuum reach 7", when it was averaging less than that at lower RPM's at wide open throttle.
———————
How is your air intake? Is it adequate in terms of the needed volume as the RPM's increase?
- Rob
I had a hunch it was restriction related. The KPAs dropping down to 90 was an indication- but didn’t think that could impact SA.
I am running AFR Eliminator 180 heads with 65cc chambers and close to .496/.495 lift on my cam (using 1.6 rockers on the intake and 1.52 on the exhaust on .465 / .488)
Intake... I am running a Renegade intake (CFI) and have a set of TBs getting bored out to 2” this week. My current TBs are bored out to ~1.9”.
When I upgraded to the AFR heads, I had to increase my fueling from 20psi to 25psi just to keep the tables close in terms of VE.
The cranking AFR is actual commanded AFR. So increasing it is leaner.
The choke AFR is a value that is subtracted from the commanded AFR. So reducing it makes the final commanded AFR leaner (less is subtracted out).
RBob.
Thanks for the clarify, I guessed right.
And when this happens: I noticed that the car will usually fire up for about 2 seconds, it struggles to run, and then stalls.
Resulting in a bit of cranking time to get it running again.
Once back up, it smells way rich for a few minutes and might take a rev or three to clear it up.
What about "Crank - prime PW", and "Crank - PW Multiplier"?
And when this happens: I noticed that the car will usually fire up for about 2 seconds, it struggles to run, and then stalls.
Resulting in a bit of cranking time to get it running again.
Once back up, it smells way rich for a few minutes and might take a rev or three to clear it up.
What about "Crank - prime PW", and "Crank - PW Multiplier"?
CRANK - Prime PW
This table is a cranking PW adder based on the engine coolant temperature. When the engine is first cranked the first two injections (TBI) or the first one injection (Port) has added to it the value from this table. This provides an initial pulse of fuel to aid in starting.
CRANK - PW Multiplier
This table changes the cranking AFR based on the percentage of RPM between zero and the 'engine running' RPM. The purpose is two fold: to lean out the AFR as the cranking speed increases, and to transition the AFR from cranking to the running state.
Thanks, and to be sure I'm not forgetting/retarded.
Next thing, I'm doing open loop wide band VE learns at wot and near wot
For the BPC - BPC vs Vac table, I want to increase the numbers to get the injectors to give me more fuel correct?
My issue: I'm maxing the ve table @ 80kph (4400 & 4800 rpm)
To make sure i'm super clear, it's currently at 139 bpc, if I raise it wo 144 the injectors should give me more fuel (assuming I'm ok with the injector DC)
Max'ing out the VE is a common issue. Easiest way to take care of it is to reduce the VE table(s) by 15%. And increase the BPC - BPC vs VAC table by the same 15%.
This provides more head room in the VE while retaining the fueling tune.
Although, with the BPC at 139, keep an eye on the injector duty cycle (DC%). You may be running out of injector.
The cranking AFR is actual commanded AFR. So increasing it is leaner.
The choke AFR is a value that is subtracted from the commanded AFR. So reducing it makes the final commanded AFR leaner (less is subtracted out).
RBob.
Thx RBob. The reason I asked is because at times, the motor is harder to start HOT after sitting for a few minutes. Also noticed that in those times it was starting a bit rich. A mechanic friend of mine, who also owns a ZR-1, commented on how he saw some black smoke at the time of startup with engine still in a warm state. And he said it smelled rich also.
So I am going to give your suggestions a go.
Nice to see this thread is still going. I haven't touched my truck in a few years, money, life, etc., but hopefully I'll be getting back into it within the next year or so.
Ok I'm not quite sure how to do a % in tunerpro, I googled how to do it in excel but my eyes glazed over pretty badly.
For now I'll just increase the area and rebuild the fueling where possible.
I'll keep an eye on the DC% as well, its not a big deal to increase fuel pressure if needed.
And a question for those that run a vac ref fpr on a TBI...
My car has cross fire fuel injection, so I have two throttle bodies.
My vac ref fpr is connected directly to a port on the side of my intake, then the map sensor is connected to a port on one of the throttle bodies.
Is this the best config, or would I be better off moving the vac ref to the other throttle body, or the map sensor to a port on the intake manifold?
Ok I'm not quite sure how to do a % in tunerpro, I googled how to do it in excel but my eyes glazed over pretty badly.
For now I'll just increase the area and rebuild the fueling where possible.
Been using the EBL for several years, but never posted on here. That is about to change! I'll chime in if I think I can help anyone out. In the meantime...
Could anyone explain the delta A/C steps terms? It sounds like it controls the minimum and maximum amount of steps that the IAC is allowed to move when the compressor is cycling. So does that maximum limit cap the steps when it is running? For example, if I'm driving around and my steps are at say "60" and the A/C currently on, but is cycling every minute, (max steps set to 30, min at 5) it can reduce that 60 steps to 55-30, but not outside that range (assuming throttle hasn't moved)? I'll also assume that that example 60 steps is dependent on the throttle follower settings. Any help is appreciated!
I've learned so many tough lessons throughout the course of tuning my current setup (383 HSR, XFI280HR, T5, 3.73s) and even my old 305. I'm tempted to start a small thread to document most of those troubles in an effort to help anyone out or assist anyone just starting out with the EBL.
I've used the EBL for several years now, and learned countless lessons...usually the hard way! I figured it is time I start posting on this thread to help others, or just gather more information. Anyways....
Can anyone explain how the delta steps works for A/C? If I am cruising at constant throttle with the air on and the compressor cycling every minute or so, how do the settings affect the IAC steps? In the previous scenario, say my IAC steps are at 60, due to throttle follower, and the A/C is cycling, does that mean that the steps will never go below 65 steps (min delta steps set at 5) and never above 90 (max delta steps set to 30) when the compressor is active? Haven't been able to maintain a running condition long enough to observe changes in steps to see how different settings affect it.
Second dilemma, closed loop idle seems to act the same no matter if i change gains, duration, or idle O2 window terms. NBO2 just bounces around like a zigzag. Closed loop at steady state driving looks fine, nice peaks and troughs, despite most of it being caused from the INT dragging the fueling around from insufficient gain. I could provide a screenshot or datalog, but I don't see the point just for that. None of the CL idle logs I have look the same. The engine runs fine in OL or CL idle, just wasn't sure why the NB behavior is so much different at idle. Maybe exhaust pulses?
Rbob, thpse changes did the trick, after a couple pulls the car is now hitting the rev limiter very smoothly! (5900rpm)
Corv3tt3, your build sounds a lot like mine but with better heads, i don't know what base bin your using, but the 3001 had a lot of settings that helped me greatly!I'm using main sa table that i pulled from a factory 89 corvette, then built up the extended sa table from that.99% of the rest was taken straight from the 3001.The o2 sensor settings helped with my idle greatly.I also had started with another bin that i found out was from an older version of ebl that someone else had started.I'm not sure what the difference was, but things started going much smoother once i started over with a fresh bin, and copied over the defined values via tuner pro.
Can anyone explain how the delta steps works for A/C? If I am cruising at constant throttle with the air on and the compressor cycling every minute or so, how do the settings affect the IAC steps?
From the current IAC position, when the A/C turns on, the IAC will open by at least the minimum value. And by no more then the maximum value.
Second dilemma, closed loop idle seems to act the same no matter if i change gains, duration, or idle O2 window terms. NBO2 just bounces around like a zigzag. Closed loop at steady state driving looks fine, nice peaks and troughs, despite most of it being caused from the INT dragging the fueling around from insufficient gain. I could provide a screenshot or datalog, but I don't see the point just for that. None of the CL idle logs I have look the same. The engine runs fine in OL or CL idle, just wasn't sure why the NB behavior is so much different at idle. Maybe exhaust pulses?
Could be cam overlap, could also be a cold sensor.
Chatted with RBob about my issue offline. This is post worthy because it’s not something that comes to mind easily.
If you intend to have a higher rpm range than what your starting BIN calls for, you could hit the SA overspeed scaler. When you do, your SA will drop. It’s not something that easily came to mind for me- but RBob found it. It’s a soft rev limiter.
Here’s the scalar-
OVSPD - RPM SA Reduction (8cyl)
Chatted with RBob about my issue offline. This is post worthy because it’s not something that comes to mind easily.
If you intend to have a higher rpm range than what your starting BIN calls for, you could hit the SA overspeed scaler. When you do, your SA will drop. It’s not something that easily came to mind for me- but RBob found it. It’s a soft rev limiter.
Here’s the scalar-
OVSPD - RPM SA Reduction (8cyl)
That is interesting. Curious, where are these two scalar's originally set for in the bin you started with?
I've been noticing an odd bucking or kick back sensation recently. Car is a 4 speed manual. Problem occurs between 1500 and 2000 RPMs with no throttle.
Idle is smooth when in neutral and no issues while on the throttle. Problem seems to go away over 2000 rpm or is certainly much less noticeable.
No unusual sounds or backfire when this happens.
Could this be something in the tune that I can adjust the bin for, or do I have some kind of mechanical problem, like rocker arms/push rods not adjusted right?
Thanks
I didn't see any response, so let me bump my own post.
I've been told this 'trailer hitching' or jerking I'm feeling could be due to the cam I have with a lot of overlap and exhaust gas is feeding back into the intake. If that is the case, is there anything I can do to tune it to make the problem less severe? More or Less timing?? How about fuel ?? Is it possible to command Open Loop for a given MAP and RPM range so I could add or subtract fuel just in this area?
I didn't see any response, so let me bump my own post.
I've been told this 'trailer hitching' or jerking I'm feeling could be due to the cam I have with a lot of overlap and exhaust gas is feeding back into the intake. If that is the case, is there anything I can do to tune it to make the problem less severe? More or Less timing?? How about fuel ?? Is it possible to command Open Loop for a given MAP and RPM range so I could add or subtract fuel just in this area?
Usually called "cam surge" is what you may be experiencing. I'll assume you're far enough away from stock settings. I experience the same thing down low with a 280XFI cam, but I have mostly minimized it.
Check if the surging is happening in closed loop, as that's a symptom of too much or too little proportional gain. Also check your spark advance; make sure it isn't jumping around too much. While there, check your VE table, check for any significant changes between cells.
What has helped significantly for my case is chucking a TON of spark advance at the motor in the range that it is bucking. At low load, part-throttle, you are correct with the self-EGRing going on. In addition to this, the mixture density is low in that region, requiring more advance to light it off efficiently. With the HSR I'm running, I have near 40 degrees of advance in that part throttle region. Try this: copy your existing .bin twice, change the spark table in one of those by maybe 2-3 degrees, and 3-5 on the other one, flash those onto different banks, and go for a drive. After using your original bin, click one of the two new tunes on the bank selector. Drive it, see how it feels. Change to the other new bin, drive and see if the additional advance helps at all. Doing it this way is a quick way to see how the additional advance can help/hurt. I wouldn't worry about a ton of advance in that part-throttle area, give the engine what makes it happy!
My surging is at a little lower RPM, between 1000 and 1500. I've been working on my proportional gains but I have no idea where to go from here. Any help would be greatly appreciated.
My surging is at a little lower RPM, between 1000 and 1500. I've been working on my proportional gains but I have no idea where to go from here. Any help would be greatly appreciated.
So on a cammed engine with a good amount of overlap, that can throw things off. My CL idle looks a lot like the Ms in your plot there. To rough in prop gains, leave the gain vs o2 error stock, and take a look at the gain vs airflow table. You can calculate the BPC for a stock engine, and you know the BPC for your engine. A proportional change in injector flow will require a proportional change in proportional gain. If a stock BPC is around 199 (port) and your BPC is say 109, multiply the entire gain vs airflow table by 109/199 (or .547). That should get you close. Its easier to see whats going on at higher RPM (2000 or so) with prop gains, since overlap won't be quite so pronounced.
Dealing with high RPM break up.
It’s not valve float- springs are new and on new heads from AFR. Heads have less than 500 miles on them.
I am seeing the RPM break up at about 4700 RPM in first gear and then 4500 in second.
First gear has the greatest mechanical advantage while second has less- so, it se me load related. And the difference in when the RPM starts to swing makes sense. The image attached shows the swings start and then get progressively worse up to 5500 RPM.
Other thoughts-
- Air flow is good (210 GMs/Sec up until break up) fueling is good (albeit a bit rich at high 10s and low 11s).
- No knock and no spark retard - sitting okay at either 35 or 32 degrees timing.
- No chatter or noise that indicates anything loose in the valve train happens during the break up. It’s just as if the tach goes all over the place.
My hunch... is this is spark related.
The coil is about 5 years old- the ignition module predates me getting ahold of the car (so, at least 7 years old). Wires are new- plugs are new. I did pull the plugs and they looked pretty good although there is less than 500 miles on them.
Now... they were gapped to .035 and in some cases as low as .030 (I had the plugs replaced when the heads were put on).
HEI alledgely calls for .045, so I did take care of that and re-gapped them.
I also swapped the HEI coil out and swapped the ignition control module out (after having Vettes for the last 24 years I have accumulated a bunch of spare parts). I tested the coil out and it was close to fail in one of the three tests.
I have yet to get it out and test it since swapping parts out and resetting spark plug gaps.
Dealing with high RPM break up.
It’s not valve float- springs are new and on new heads from AFR. Heads have less than 500 miles on them.
I am seeing the RPM break up at about 4700 RPM in first gear and then 4500 in second.
First gear has the greatest mechanical advantage while second has less- so, it se me load related. And the difference in when the RPM starts to swing makes sense. The image attached shows the swings start and then get progressively worse up to 5500 RPM.
Other thoughts-
- Air flow is good (210 GMs/Sec up until break up) fueling is good (albeit a bit rich at high 10s and low 11s).
- No knock and no spark retard - sitting okay at either 35 or 32 degrees timing.
- No chatter or noise that indicates anything loose in the valve train happens during the break up. It’s just as if the tach goes all over the place.
My hunch... is this is spark related.
The coil is about 5 years old- the ignition module predates me getting ahold of the car (so, at least 7 years old). Wires are new- plugs are new. I did pull the plugs and they looked pretty good although there is less than 500 miles on them.
Now... they were gapped to .035 and in some cases as low as .030 (I had the plugs replaced when the heads were put on).
HEI alledgely calls for .045, so I did take care of that and re-gapped them.
I also swapped the HEI coil out and swapped the ignition control module out (after having Vettes for the last 24 years I have accumulated a bunch of spare parts). I tested the coil out and it was close to fail in one of the three tests.
I have yet to get it out and test it since swapping parts out and resetting spark plug gaps.
Thoughts? Am I missing anything?
You say the fueling is good, but what is the injector duty cycle when it starts happening. When you get close to and over 100% duty cycle on a TBI system you can have a wideband showing plenty of fuel and still have the engine break up badly, FWIW.
You say the fueling is good, but what is the injector duty cycle when it starts happening. When you get close to and over 100% duty cycle on a TBI system you can have a wideband showing plenty of fuel and still have the engine break up badly, FWIW.
Fast- I achieving my max duty cycle between 82% and 85% at 5500 to 5700rpm and between 10.8 : 1 and 11 : 1 AFR. FWIW- 5500 is the max RPM I’d like to routinely see.
I’m closer than I’d like in terms of duty cycle, but would the duty cycle fluctuate +/- 2% in and around those RPMs?
I recently realized that I was never, ever getting any DFCO.
Last night I tweaked the DFCO Upper/Lower values for MPH, RPM, and MAP, and also bumped the Enable TPS Threshold to 2%
I am now seeing an occasional engagement of the DFCO, but it is very brief. Only a few tenths of a second. A few frames in the data stream, and then it goes back to the 'normal'.
In looking at the data points immediately before and immediately after the points where I get DFCO, I see no difference. The TPS, MAP, RPM and MPH are all within the limits of where it should be enabled.
In a 15 minute test drive, DFCO enaged probably 5 or 6 different times, but each time for less than 1/2 second. Any thoughts on why it won't stage engaged for more than a few 1/10s of a second?
I am now seeing an occasional engagement of the DFCO, but it is very brief. Only a few tenths of a second. A few frames in the data stream, and then it goes back to the 'normal'.
It is due to this parameter: DFCO - MAP Increase to Exit
The early XDF files have an incorrect conversion. It adds 20 KPa to the value when it shouldn't. So the MAP increases a little (about 3 KPa), and DFCO exits.
Can either just make that parameter 20 KPa higher (to 43 KPa). Or change the conversion of the XDF file in TP. Change the equation where it is adding 20 and make it adding 0. Then enter 23 KPa for that parameter.
Change it from this: 0.312500 * X + 20.000000
To this: 0.312500 * X + 0.000000
RBob.
P.S. not sure which version of the ECM firmware you are running. But it is worthwhile updating.
Tonight I went on a 3.5 hour drive to my hometown. The entire way home I was doing EBL WB O2 learns. Everything was running great and eventually the learns started to make very minor changes.
I stopped at a gas station about 3/4 of the way home and refueled. I then got back on the freeway and thought I’d try to do some VE learns in D instead of OD (I have a 700R4 so usually stay in overdrive to keep the RPMs reasonable at freeway speeds and to save fuel)
Once in Drive, my RPMs jumped to around 3000 (going about 70mph). Immediately, I started to notice a driveline pulsating vibration that was light but still pretty rough so I put the transmission back in OD and the vibrations went away.
I looked over at my laptop and noticed a lot of knock counts. I figured the vibrations caused them so I cleared the knock counts and figured I’d just stay in over drive the rest of the trip and troubleshoot the vibration later.
This is when things got weird: The knock counts kept appearing in very high amounts (255 at some points!) and wouldn’t stop. This is all at cruising speeds while my AFRs remained normal (13.7-13.9) and the engine continued to run smoothly.
The rest of the trip (about 30 minutes) was like this. Non-stop knock counts and lots of spark retard.
I don’t know what’s causing the vibrations while in drive but would driveline vibrations cause knock counts? I think it’s really weird that as soon as I left the gas station and placed the transmission in D then back into OD after noticing the vibration, that the knock counts wouldn’t stop.
Maybe I loosened something up and now that “something” is causing all these knock counts?
I have a tuning day scheduled this next Saturday with Kevin Lorentzen and was hoping I could clear this up before then. Any help/ideas on what to look for would be appreciated!
I finally got to drive my Caprice that I swapped the Vortec L98 TPI engine into. I have it starting and running well enough to start tuning, the WB O2 is working so I can use it for tuning. The engine is very responsive to the throttle and I think when I get it dialed in it will be a blast to drive for a large car. When i drove it I noticed the TCC was not locking up. Also there is no TCC light or hi gear light on the WUD. I am using the EBL P4 3005.bin 5.7 TPI auto. I have not changed any of the TCC parameters, scalars or flags and when comparing bins the settings look to be the same. Can any one please help? Also is there any way to switch Tuner pro to use F instead of C when setting up CTS temp settings.
Thanks
I am still trying to nail down an issue between 4800rpm and 5500rpm. Seems that I am getting a flutter that starts at 4800rpm and continues to get worse through 5500rpm.
The AFR heads went on this year- but looks like at one point with the stock heads it was perhaps starting to flutter last year. New transmission went in last year. Seems to still pull hard through it's RPM range.
Fast355- Fuel pressure is good. In fact, I replaced the pump recently because it bled off too much.
I have four years of logs- so lots of data over the years. Here are logs from the last three.
Any ideas? Lash perhaps?
Mods...
OE TBI units bored out to 52mm
Renegade Intake (aftermarket cross ram)
90lb injectors
Aeromotive Variable Fuel Pressure Regulator (23 at idle / 28psi at WOT)
I’ve been thinking about this a lot. For a 300 to 500 RPM drop, I would expect some type of misfire or something else. The car runs well- the mph and AFR confirms that.
I am going to swap the distributor out for another that I have and see what happens.
I am wondering if there is a signal issue at this point.
06-17-2018, 06:41 PM
