Check what the INT is doing, along with the possibility of a lean area in the VE table.

RBob.

 

If I display my Malfunction codes, I have an intermittent IAT LO (23). Pretty sure I have a loose wire. Anyway, the SES box in the WUD is not lighting up despite the MALF code. Is that because the IAT 23 MALF flag is not enabled in the BIN, or should WUD light up the SES regardless of the bin setting?

 

Only the cars have the IAT sensor. The 1st column will blink without a sensor connected. With the IAT LO 23 flag not set the code won't go any further.

The center column controls the SES/CEL light, with the 3rd column being a stored code.

RBob.

 

What are some signs of too large injectors being used?

I am starting to believe that might be part of the issue. I just can't seem to get my fueling figured out. My learns always seem to go way to far in the corrections and never meet in the middle...Currently running 36lb injectors on my setup that's in my sig.

I just feel like I am going in circles with these VE tables and cant find the reason why. I don't have any exhaust leaks anymore and really thought I would be able to get this thing reliably drive-able.

 

Too big of a fuel injector usually shows up as idle issues. As that is typically the smallest PWs are used that have a major affect on the engine.

The VE going is circles can be a fuel delivery issue. Any variance in delivery (pressure) will affect the resultant AFR.

RBob.

 

VAFPR? What brand and have you inspected diaphragm? Will it hold pressure using a Mighty Mite? What are your DC's at cruise RPM low load low MAP? My always changing VE logs were a result of vac leak some years back. Interface at header collector to ext pice where the NB 02 sensor was located. Why 36 injectors?

 

I am running a external adjustable fuel regulator set to about 43-45psi. I do not have the vacuum hooked up. Not sure what you mean by mighty mite? Is that like a manual vacuum pump?

I will get a datalog up once I get home. I know from memory I idle at about 4% DC and I believe ~2.7ms on the pulse width.

Far as I know there isn't a vac leak that Ive found. My WB is mounted just after the y-pipe comes into the single pipe/intermediate pipe. Practically brand new sensor with new LC-2 programmer.

I went with the 36 injectors because they were a good deal at the time and I thought they would work out ok. I knew they would be a little bit on the larger side for this build but wanted some room if I decided to do anything more with this build. They are seimens deka injectors that had just been serviced at southbay if I remember right.

 

I would hook up vac to VAFPR. I don't see how that would hurt. It will affect your VE temporarily until you have the new VE dialed in. Yes MM is a manual vac pump. 4% seems OK. 2.7 ms seems OK. From my experience anyway. Are you also using a NB 02 sensor? I never ran my NB02 that far from the header collector. Nor my WB. Both are 12 inch from header collector. I am using the NB02 and also the WB only for a separate datalog. WB not in control of A/F. Something is affecting the A/F. Again ext leak is probable cause. Been there .........!

I would lock out asynch and run synch with large injectors. Do you see both showing changing values in WU logs?

 

The FPR should be connected to a plenum vacuum port. This is because the outlet of the injector is subject to manifold pressure. Which if not vacuum referenced will cause the injector flow rate to change as the intake manifold pressure changes.

Note that this is for a MPFI setup.

I'll bring up injector compensation data, but not sure what can be done about it. I know of no known data for Deka 36#/hr injectors.

RBob.

 

I will get that hooked up then. When I get home tonight I will try and do that then go for a drive and do some VE Learns again. I will also give a datalog as well. Got busy last night. I have changed the injector compensation data to attempt to get it closer. Took some info from similarly sized injectors and kindve averaged what I found out. I can definitely tell it is still wrong due to it going leaner as the voltage goes down.

 

Messed with it some this evening and didn't have much success. I did get the vacuum hooked up to the regulator. Went for a drive and I experienced some missing and what seemed like a electrical issue cutting things out. Experienced this some before and thought at the time it was due to being lean. But I'm doubting that now. Going to look into this deeper when I get some time and hopefully come up with an answer. Thinking I'm having mechanical/electrical issues that need addressed before I do any tuning.

 

Maybe some compensation info here. I have not checked.

gearhead-efi.com

When I purchased my injectors the vender provided the compensation data without me asking.

 

Update...

5.2 to 5.4 second 0-60mph are some of best times I have gotten out of the Vette.

Attached is a really crude image where I have an overlay of where I started out with the car with only a mild Compu-cam. The before image is the only one I have in terms of historical documentation- so it is not perfect. It is directional at best because the throttle stab isn't exactly the same. Regardless, the 2.87 and small cam didn't make much difference anyway you stab the throttle.

EBL and all the mods supporting the .465" IN / .488" EX cam on a 3.73 rear end has garnered a huge increase in acceleration on stock wheels, tires, and exhaust.

The car is NOT a drag racer- I just wanted it to run better and be a little quicker.

 

Got my plug wires replaced and that helped a lot. Apparently my wires had some burns from being routed under the headers that was not visible. Ordered D.U.I. sleeved wires and got them all installed. Anyways took it for a test drive using a old tune that I remembered was a decent tune that was driveable at the time with the motor the way it was now. It was before I did the TKO 600 swap.

It is a lot better then it was before. Now I've still got a lean issue that shows up. I'm thinking its a combination of a heat soak condition and not having a true cold air intake. Just running a filter on the throttle body. As well as the correction offsets being off.

Here is my data log and the two tunes I ran during it. I switched to the test tune about half way through the datalog, right before the hard acceleration.

Datalog & Tunes.zip

Any thoughts on the datalog and changes I could make to help? Other then the obvious getting a cold air intake installed and figuring out some offsets.

 

I've had a busy week but finally able to look closer at that datalog. You can find exactly where things go lean at about 5:03 on the run time. Which is exactly when the fan first turns on. The IAT temps start climbing almost immediately. The IAT is a plastic cage style mounted right next to the throttle body opening/filter. Accurately showing temp of whats being pulled into motor. The temps climb from about 92F to 113F in 10 seconds. Reaching 130F in about a minute.

So right now I'm pretty convinced that my lean issues are coming from the "open engine compartment air" setup I have. Currently looking into options for a cold air intake. My Ram Air II hood is opened up at the nostrils but didn't come like that. I'd like to get the cold air intake from Hawks that is made for these hoods but am worried that since mine wasn't built as an open hood that it wont fit properly.

I might try and fab up something to direct/keep the fan air from the throttle body area. Hoping to look into that this weekend. Only other option would be getting some intake tubing and connectors then routing it to drivers side fender opening. My battery isn't mounted in the drivers side due to not being an original TPI car. I might end up having to move it to that side, because running a intake tube to that side looks like it will be tight if not impossible.

 

You can reduce the affect the IAT has on the injector PW by changing the blend table:

IAT/CTS - Blend Filter

By increasing the value(s) the IAT has a lessor affect.

RBob.

 

By doing so will it change up fueling substantially? If I change it to like 75:25 CTS:IAT?

 

It can, but note how the table values are tapered. More CTS at low airflows and less at higher airflows.

RBob.

 

Placing all values at 100% will place all fueling at coolant temps solely. That is what I did before I had IAT control. Could do as an experiment and rule that one out. I found IAT addition to be a good thing for me.

 

RBob maybe you can assist me in diagnosing this miss under load I have developed. It seems that when the vehicle gets up to temp it will start jerking under load such as when the TCC locks up. It will also stumble coming off the line. I thought ignition issue so I checked the cap, rotor, and wires and all looked good. The motor only has about 14k miles on it to the plugs are relatively new.

In my data log below it is happening badly at 5:53 mark. I do see the O2 go lean. I should add that this issue is also present at idle. You can hear it stumble and what sounds like an injector clicking.

 

I chased my tail with getting the IAT and CTS bias where it needed to be for a while. Sounds like you might have the same issue from your other post.

 

Under load is higher MAP. As the throttle opens MAP drops and fuel fall out of atomization. I would add more MAP-AE and see if that increases the NB02 voltage at the area you see the issue in log. WB02's are helpful in this regard. AE throttle follower could be increased a little as well. Too much AE-TF and fuel mileage suffers

 

Minor correction...

Quite correct.

As throttle opens MAP INCREASES !! ( it's an easy mistake to make, saying the opposite of what your brain means to say )
( What ? It's just me ? )

Condensing on the manifold walls, to later evaporate and cause a rich spike on throttle lift.

 

Hi-Sorry for the noob question..but can someone explain the differance between the "program" and "read" buttons on the flash page of the WUD?
Should they have the same name?

Thanks!

 

The "Program" action is used to send a BIN/Calibration to the ECM. This is the most commonly used action. As it is used to program the ECM with a calibration. Which is used after changes have been made to the BIN/Calibration.

The "Read" action is used to get the calibration out of the ECM. IOW, if a hard drive crash, or a new laptop is used, this action can be used to get the current BIN from the ECM. Which then can be used to continue tuning.

RBob.

 

Yep I misspoke. Brain fart. Throttle opens MAP increases vac decreases. Heavier load higher MAP and lower vac.. Fuel falls out of atomization with throttle opening. A downside to TBI. I believe that is reason throttle follower AE exists.

 

It's the reason AE ( or "pump shot" ) exists anywhere, including concentric venturi motorcycle carbs !
Pressure rises everywhere after the throttle blades, including in the cylinders.
As pressure rises, fuel condenses out. It's just physics. The question is if it matters ? Where it does, "pump shot" is intended to make up the difference in the atomized mixture. Where it really matters most, is in the spark plug gap !

Where it can be a problem, in an engine "on the edge" the excess fuel condensed between the piston and cylinder wall above the top ring, is a frequent "advantageous circumstance" for detonation, so to speak.

Like most things, there's a trade-off.

Port injection simply lessens the places the condensation can happen. ( yes, among other things )

 

I believe pump shot or AE MAP AE TPS is for the more dramatic throttle openings. AE TF is for the more gradual opening of the throttle. Both are contributors of reduced VAC increased MAP.

Makes me want reread Aaen tutorial on Mikuni carbs as to how they compensate in that regard. I left carb this year in total on my sleds

 

[QUOTEWhere it can be a problem, in an engine "on the edge" the excess fuel condensed between the piston and cylinder wall above the top ring, is a frequent "advantageous circumstance" for detonation, so to speak.
][/QUOTE]
Flame speed across the piston top? Residual fuel to allow detonation earlier than desired?

 

I presume a tighter gap to assure flame not blown out?

 

Has to do with the shape of the slide. That curve at the intake side working against the straight edge on the out side changes the aerodynamic just enough...
Rather ingenious, really.

No. Detonation is an extremely fast ( supersonic ) self-ignition of fuel. Oxygen not required, only pressure !
The cylinder and piston walls absorb enough heat that the flame never gets there, but the pressure does ! ( this why there is always some unburned hydrocarbon in the exhaust. The cat-con takes care of it )
Detonation is never desired ! The relatively slow burn of the flame front, is desired.

To assure the flame kernel gets started at all !
To have a combustible AFR in the gap. Too lean, it won't light off. Once lit, the AFR can be off by quite a bit, but in the gap it has to be close, else you get a miss.

The purpose of AE is to assure that in spite of condensation, there is some properly atomized AFR in the gap itself.
Decel enleanment is the converse, but since we are seldom concerned with making the most power when we're trying to slow down, it's primarily to preserve the life of the cat-con.

 

This sounds like something I may be having a problem with. I have a 90 SCSB 2wd chevy pickup with a 5.7 and 700R4. Runs great now that Ive tuned on it awhile-even got 24MPG on a medium long trip, and, at the time, had lean cruise turned off. Anyway, Ive noticed that when cruising along in 4th gear at anywhere from 45-65 MPH, if I the road starts to rise and I give it a hair more accelerator pedal, nothing happens. As I give it more and more, it kicks into a lower gear and accelerates just fine. I know I have the torque to pull the slight rise without the kickdown, but it seems as though the computer is ignoring the TPS and not enriching the mixture enough to maintain speed or even slight acceleration. Which AE table should I address? Or is it something else I need to look at? It only seems to happen in 4th gear.

 

That's not AE. AE is only in effect for a few revolutions of the engine.
In your case, need much more of a data log to make any assessment.

 

Ok. Let me see what I can do....

 

With a manual transmission, what IAC and/or TPS parameters can I adjust to get the RPM's to drop more quickly on clutch in? I have a problem at clutch in coming to a stop, where the RPMs take what seems like an excessive amount of time to return to the normal idle. Also, when accelerating, RPMs don't drop as I would expect when pushing the clutch in to shift.

 

Throttle Follower (TF). It is when the IAC follows the TPS% as it opens and closes. To adjust it for shifting you can limit the total TF steps, and can change the gain of the TPS% versus IAC steps.

Then as the throttle closes, there can be a delay before the IAC starts to step closed. Plus there is a decay rate that can be adjusted.

RBob.

 

After reading the above, on a full throttle stomp, would this effect its response? I am trying to get more FULL PEDAL response... I have a super great smooth pedal performance... and am really hesitant to tune and mess it up... but would like to get the pedal stomp spin the tires, back... any insight on how to dial that back in with a great tune... I would imagine its a balancing act. But where should I start as to not mess with the main tune.... IAC sounds like the ticket... If I were to describe she runs great smooth steady firm pedal... great 0-60... but smash is not good...

Looking for above and beyond to get some back...

 

Hard to say, in the 3005 BIN the AE - IAC opening fuel is set to 0. Being an auto the convertor has a lot to do with a stomp.

There is also launch mode (LM) SA that can be used to bring the engine up against the convertor.

It may also be going rich or going lean, adjusting the AE will tune this in.

RBob.

 

Forgive me if this was covered, but I didn't read all four thousand posts in this thread.

You guys running the port mod, with large high-z injectors. Say 60-120lb injectors.

On some of these injectors, like mine, the dead time is upwards of 1msec or higher. This makes it quite difficult to idle with typical double fire batch.

I'm curious how you guys are doing it - are you using single fire at idle, and double fire everywhere else or something else?

I know some members have reported sub 1msec idle pulsewidths and stable AFR at idle, but I find that hard to believe.

-- Joe

 

Thanks Rbob. I was reading through some other threads for more info on the IAC - TF Gain parameter. In those other threads people talk about having gain % of 70%, 100%, I think I even saw someone with 200%. The BIN I am using (EBL_F_2002) as a basis has only 12.55%. Do I want to go any lower with this, or should I be raising it higher to get my RPM to drop faster? Not clear on which way this one needs to move to achieve the desired outcome. Thanks.

 

The higher the gain the further the IAC opens. On stick vehicles I like to set the gain so that as 100% TPS is reached the IAC has reached the max allowed steps. Which can also be increased to add airflow (both max steps and max TF steps).

Then adjust the decay rates to match your shifting. A higher decay percent is a faster decay (IAC closes more quickly).

Be aware that a delay can also occur on a throttle lift. I like to set those to zero (see the 3001 BIN).

To see the available parameters open the calibration help doc. Then hit CTRL+F to open a search window, enter w/o quotes "IAC - TF " and highlight all. That will show the TF parameters.

RBob.

 

I'm still getting the hang of tuning, however I have managed to get it running decent...

One issue I'm having is related to ebl not seeing the difference between D and OD, if I flip the option it stays as OD, if I flip it back it's D no matter what.
I did a transmission rebuild right before all of this, very possible I damaged the switch. That or I have a wiring mistake.
I'll replace the switch when I have the pan off this spring and see how it goes.


Few questions
First
RBob, you mentioned a bin flasher at one point, I was thinking it would be perfect for a little security device.
Still available?


And for reading the ebl log, is there a cheat sheet for what each column relates to?

 

see "intro to tuning" on RBobs site. dynamicefi.com

Also see stickies on DIY Prom for terminology help

 

Thanks, i did see some basics on RBobs site and i have been spending alot of time searching trying to avoid asking redundant questions.

What i have now is i have a wide band sensor setup and I'm trying to get the fuel mapping setup, learns plus exporting the log to a csv and reviewing sections I'm focused on and then building my ve table in the higher rpm.

What i cant find are clear definitions of the columns other than the few mentioned on RBobs site...

 

Set the option so it shows D. Once the transmission actually shifts into OD (4th), then the WUD should show OD. If it doesn't then as you mention, bad switch or wiring.

Not at this time.

See the WUD help document:

Start->All Programs->EBL Flash->What's Up Display Help

RBob.

 

Thanks, and there it is at the bottom!

 

I think I found my 4th gear problem...


In the wiring diagram cheat sheet(84 CFI), it lists two pins with the same wire ref


6 - C7 (third gear discrete)
22 - C7 (fourth gear discrete)


I started with the top of the cheat sheet and worked my way down, by the time I got to the end I found that 6 and 22 were the same pin so I left the third gear wire.


Should I remove third gear and replace with the 4th, or wire them together?

 

There is confusion or discrepancies among the various wiring diagrams over B6 & W22. I think it may also varied among the various x-fire years.

Try it on B6 GRY/RED wire. That is for 4th gear on an auto, or 2nd gear for a manual trans.

With W22 DRK GRN being 4th gear switch for a manual trans.

That is from a GM '84 Y-Body connector pin out diagram.

RBob.

 

Here is the pin diagram from my 84 (corvette)


And I have my car up on jackstands right now, I shattered my front trans pump while having some fun, so It's coming out again.


I can do some wire traces and even run new leads while I have the drive train out.

 

I made a crosswalk from RBob's wiring instructions. I have an '82 though. Left side is crossfire to EBL and right side is EBL from crossfire.

I have also cross-checked it with a few schematics to make sure it was right.

The numbers with no letter identifier are from the crossfire harness. The alphanumeric indicators are for the EBL PIN.

So, "## - X##" means "crossfire # to EBL PIN location"

NOTE: The provision for the IAT (MAT) sensor gets plumbed in by you if you elect to use one. It's not part of the standard harness.