bizzybone485

Title should read IAT, not IAC

Hello,

I have had the EBL Flash for some time and have recently had some time to tweek things a little. I realized that during my datalogs, the IAT stay at 40 C while the CTS changes and goes upwards toward 100C. How do i get the EBL Flash to start reading IAT temps so things will change acccordingly?

Also, with the EBL Flash i remember reading when i got it last year that in order to do the VE learn you have to cap off the EGR valve and delete it or something? Im fairly new to the EBL so please forgive me.

Thanks for all your time!

God Bless


P.S : This is for a mild 355 TBI in a 1991 single cab short bed Chevy truck. It has bolt ons, mild cam, tbi performer intake and TBI mods. Any information needed please ask.
Ulysses

RBob

iTrader: (1)

The TBI trucks didn't get an IAT from the factory. Easy enough to wire one in. Pick up ground at the CTS block ground, then wire the other terminal to ECM pin C12. No polarity.

For VE learns it is the CPP that needs to be capped. This is to prevent canister purge from changing the fueling. The EGR just needs to be disabled in the calibration.

The Intro to Tuning Part 1 and the What's Up Display doc have additional information on setting up and running VE Learns.

RBob.

bizzybone485

Rbob since your the man to speak to about this program and tuning in general, I have a few questions and thought i would just post them here.

So here is a Split second of my WUD:

Background:
1. I'm running WOT after a short stop on the highway due to an accident.
2. At this moment a sound is let off by the EBL(maybe due to SA Retard?)
3. I am soon about to hit 85%DC at about 4000rpms (Yes i need a FPR BAD!)
4.This was on a VE learn as I am slowly smoothing the VE tables out.
Questions:

1. Does this look ok?
2. Why did my IAC max out?
3. Was that noise due to the Spark Retard?

bizzybone485

I'm currently in the process of smoothing out my VE tables through the learn function. I wanted to add that for some time, I was using table #2025 for a 502 running 80lbers at 24 psi. How it ran as good as it did I don't know but i did a lot of learning in the past(on the wrong startup table) and all seemed to be good. I was also using the crazy high spark tables and surprised my motor never blew. Could that be because of my lack of fuel?

Anyways, my computer crashed the other day and i had to restart the process and that when i found out that i was using the stock bin 2025 all along. I proceeded to try out the original stock bin2010 for 5.7 350 TBI and this is when i found it to run terrible so i mixed and matched the two tables where needed using mostly the 2010(with 2025 VE tables).

Well one thing i found interesting was the SA Latency was different in both 2010 and 2025 and i believe this could have been adding to my problem of the terrible idle, surging when moving from a stop sign, and just barely running.

I am currently running the big block VE tables and SA Latency from the 2025 bin while VE learning and smoothing them out with the rest coming the 2010 bin.

bizzybone485

Who thinks I should add some fuel pressure?



Yup time for an upgrade. Wow i didn't know they went that high!! 113% Yikes, working hard!!

RBob

iTrader: (1)

Yes, it looks OK. The IAC max'd out from throttle follower (TF). This is where the IAC is opened as the throttle is opened.

The laptop can make a sound when knock is reported. With the 1 deg of retard it is likely from that.

In the Preferences dialog this can set it so it won't make the sound (un-check the Knock Alert Sound box).

While there also set the auto radio button for the gear indicator. Then at key-on engine-off the WUD should show P/N. Can then move the gear selector to any drive position and it should show 'D'. If it shows 'OD' then need to flip the high gear polarity option flag:

Option Word 2 - Bit 5 - HiGrH

This is so the EBL ECM uses the correct set of TCC lockup tables.

RBob.

RBob

iTrader: (1)

Can also read the current calibration out of the ECM and go from there.

RBob.

bluers91

What does the %DC mean? When it hits 100% you need more fuel pressure?

RFmaster

DC= Duty Cycle (injector duty cycle) - which means that injector stays open as long as it can between pulses. Increasing fuel pressure allows fuel injectors can deliver more fuel to satisfy engine appetite. With increase in fuel the duty cycle (DC) will drop below 100%. VAFPR is best suited for this since at idle excess fuel pressure will result in very short pulse width which TB injector can not maintain (less than 1.0 mSec) due to mechanical inertia.

In bizzybone application VAFPR that delivers 14 PSI at idle and 22-24 PSI at WOT with a pair of 61 LB-hr should be considered.

//RF

bizzybone485

Thanks for all the help Rbob,

As far as DC and fuel pressure, I just purchased a 8-40psi FPR from xtremefi last night so im gonna work with that and pray it doesn't "bottom out". I was trying to stay away from the VAFPR till i started messing with boost because it seems that it can be a little more difficult to tune it and in the stage of tuning that i am in, i need as little variables as possible to screw around with.

bizzybone485

I'm estimated at about 270-280 HP using DD2000 so im gonna throw 20psi with my 65lbers(rated at 305 with EBL utility) and go from there. If i have slight idle trouble, I still have the stock 55lbers and can see if that clears things up. I have a 190 fuel pump so i think it will work out. I dont have a WB O2 just yet. That should be coming after Christmas and then ill get serious about tuning WOT.

bizzybone485

Rbob, I noticed a post in the EBL manual where you gave steps on how to re-enable the EGR. I have had both the CCP, EGR, and Lean Cruise disabled for VE learns but not really clear on what to do next to get everything back together. I dont understand the reason for more VE learns after EGR is enabled but without flashing the bin... Also, Im confused about the rest. Thanks!

RBob

iTrader: (1)

There is a table that modifies the BPC when the EGR is active:

EGR - BPC Multiplier vs VAC

Note that it is based on vacuum, not manifold pressure. And the EGR replaces oxygen with inert gases, so the engine requires less fuel.

By doing a VE Learn it will show you if and where the fueling is off. Using that data change the above EGR table. To convert the MAP value to a vacuum value, subtract the MAP value (in KPa) from the barometric valve (look at MAP at key-on, engine-off).

The result is the vacuum in KPa.

RBob.

bizzybone485

Ok so i did an 11 mile VE learn for the EGR tune. I took a snapshot of the VE corrections. Im not really sure what to do with them as you said considering there are so many different variations through rpm vs map. Any input at this point would be great! Thanks


What i don't understand was why it was trying to add fuel in so many areas. It was around 55 degrees when i did the EGR VE LEARN tune so i don't know if that had anything to do with the added fuel.

Also, the EGR- BPC Multiplier vs VAC in tunerpro shows up as such....

Id like to add that these are untouched variables with the stock tune and I have yet to touch them.

RBob

iTrader: (1)

If there isn't an IAT and the temperature dropped the BLMs will increase. Even with an IAT the BLMs will move around some what from a change in ambient temperature.

RBob.

bizzybone485

hmmm interesting. Yeah i noticed this as well without the EGR enabled today. What is the explanation for this? Is this the reason for the IAT in the first place? Helps the motor to run better throughout a variety of temps? Thinking this makes me want to install the IAT sooner.

RBob

iTrader: (1)

In many ways it really doesn't matter that the BLMs move around with changes in ambient temperature. As long as the engine runs OK, they can move around.

The flip side of this is that GM did as much as possible to maintain a consistent temperature of the intake air/fuel mix. The air cleaner has exhaust heat that is thermostatically controlled. Along with a full water jacket around the plenum and under the runners.

This consistent temperature gets foobar once the air cleaner set up is changed for colder air.

What is interesting about the use of the IAT in the 1228746 ECM is that it is used mainly for spark control. Likely to avoid detonation on a hot engine. IIRC, the IAT isn't used for fueling.

RBob.

Ronny

iTrader: (1)

I presume that is for GM-ECU. does the EBL use for cooling as well as spark?

I am using stock EBL.bin settings for IAT vs coolant. Any reason to deviate? see photo.

[IMG][/IMG]

RBob

iTrader: (1)

Correct, the stock GM 1'8746 ECM.

In the EBL can blend the CTS into the IAT for fueling and SA.

RBob.

Ronny

iTrader: (1)

Any reason to deviate?