RBob,

Yes I think you did. But just to be clear, I will make changes to the VE table to match the Commanded AFR and leave the PE Enrich attack rate etc. as is.

 

My engine has that "sluggish" feeling such as giving throttle but getting little response (off idle and light/med throttle) in the early mornings when it is cooler out (using IAT). Should the IAT/CTS settings or the SA Coolant Comp Spark Advance be adjusted.

 

It could be the SA Coolant Comp Spark Advance, or too much AE. I would look at the AE first. Second would be the overall AFR. There is startup fuel added that may also be too rich.

Better off leaning things first (if required) before adding timing.

RBob.

 

Thanks Rbob............I'll do some logs and checkout those areas.

 

Who thinks they've had the best luck with their WB02 and the EBL combo, I know a few people have been running into problems just wondering which to get since I don't think I can advance too much more without one and am ready to make the big purchase.

 

Well I have the EBL and yes it's nicer for tuning but, I just ordered a wide band O2 and a EGT. There is only so much that you can do with a narrow band O2. I'll let you know how far off the narrow band was once I get the WB up and running.

 

No question that the hot setup is EBL+WBO2+Ostrich+TunerPro. This has made tuning soooooo much easier than dealing with a scantool at 1frame/sec.
Imagine going through a 2.5 hour datalog and re-calc a new VE table in 3minutes.
IMO, you need to know where you are WOT-wise before you can tune part throttle. This is particularly true if mods have included cam and heads. You need to get the FP right for WOT and then go from there. The ZT-2 Zeitronix has worked well for me in this combo.

 

Isn't that the truth. I know exactly where you are coming from. It does NO good to tune for part-throttle, if you are about to have to give it 10 psi more fuel pressure than it already has to make it run decent. My stockish 350 wants 32 psi on 61# injectors in order to pull 5,600 rpm out of it.

 

Alright, so I'm tuning mine with this EBL setup now that I got my mechanical stuff straightened out.

I'm working with VE tables, and I already set my BPW constant.

I'm at 30 psi of fuel pressure and i'm still maxing the fuel tables in certain spots (100% VE). What should I do? Damn this motor wants fuel! I dont think I should turn it up any more!

Also, my idle is good, but not perfect. How can I perfect my idle? I haven't begun to adjust any of the IAC settings or anything.

My 383 runs pretty good. I nailed in in 2nd gear and the road was a little wet, I found myself sideways, and I have 40x18.5 tires in back!

 

What size injectors are you using?

 

Exactly the same. Also now agree with the WOT/FP statement after having to start over several times after raising FP to feed WOT.

 

61 lb/hr.

 

They are 96 lbs/hr now! Mine are 100 lbs/hr.

Downzero, told you that the throttle response would be good.

My 350 will put my Van with P295/50/R17s sideways.

 

Down,

You need bigger injectors. I am running 80s with 20psi FP and getting 75% DC at WOT. That calcs to 99lb/hr. Ben 73 has a 383 stroker motor and runs 90s. He reports that his DC% is about 90% at 20psi.

 

Whoa, wait just a second, his 61# injectors at 30 PSI are equivalent to 96 lbs/hr. Mine at 32 PSI are like having 100 lb/hr units. Running my old 68#s at 35 PSI was like having 116 lb/hr injectors and they were on a 312 (.040 over 305), I was still hitting 87% DC @ 6,300 and almost 90% @ 6,500.

 

Fast,

Well you want more headroom for DC. The larger injectors don't need the higher FP to deliver the same amount of fuel. This reminds me of a thread on the Corvette Forum where a guy named "ski down it" thought it was better to use smaller injectors at higher FP. Not saying that your combo doesn't work, but my approach is to use an injector sized more appropriately for the application rather than just bumping FP. The higher the FP the more difficult it is to control idle due to the very small PW needed.

 

More fuel deliver = shorter pulse widths at idle, period. It doesn't matter if the added flow is from bigger injectors or from more fuel pressure.

He already had the 61#s and I gave him a way to make them work with his application.

For TBI, I personally like smaller injector at higher pressure. It aids in atomization and efficiency. Fuel burns in a vapor state, not liquid. The better you get the fuel atomized the higher the efficiency. Makes for improved HP and better fuel mileage.

I agree with him, use the smallest injector that you can reasonably support your combo with. I use 35-36 PSI as the pressure limit for my TBI builds, GM ran between 26 and 32 PSI on the last 454 TBIs, I pushed their ratings a little. I am not too worried about injector, fuel pump, fuel line reliability either as the fuel lines for a late TBI 454 are the same as an early 454 or even a 350 (in the G-series atleast) and ran at 26-32 PSI. At 36 PSI, I look for bigger injectors.

 

My understanding is that the "atomization" takes place on the walls of the TBI. The idea is to have the fuel sprayed on the sides of the venturi, where the air velocity "shears" the fuel and atomizes it. Thats why you want to minmize the effect of the IACs.


I wouldn't doubt that. I personally have not heard of those pressures. I had always read that the BBC injectors were rated at 13psi. The Xfire ran 64/66 injectors at 10-13psi. Since these are individual TBIs, I needed to parallel plumb the fuel lines and replaced the stock injectors with the 80s. Until I doubled the FP to 20 psi, the injectors were static at WOT. Care to share what you gave Down to make the 61s work?

 

To a large extent it does, but the smaller injectors give a finer spray pattern than the larger injectors do.

I helped Down in the idea to run the fuel pressure up way high, he is running 30 PSI.

 

My BLM at idle is really crazy (172?) but as soon as I crack the throttle it goes to 128 or so.

I'd say with the way it is idling, I'm too rich at idle. Is that the case? How do I compensate? Pull fuel from the 600-800 RPM range? (VE tables?)

My engine is starting to run a lot better, but still doesn't quite run to its potential. The idle is pretty choppy right now (sounds like I have a nastier cam than I do) but other than that, it runs great. It will crawl right through the brakes in 4 low, and I'm really confident in it turning out quite well, thanks to you guys.

I really don't think bigger injectors would do anything at this point. Like Fast said, more FP = bigger injectors. I've already got bigger injectors, I just got them by cranking fuel pressure rather than by changing them.

 

Fast,

Have you found a point of diminishing returns? IOW, at what point does more pressure contribute nothing? What difference have you found between running the FP at 20psi and 30psi?

 

There is no diminishing return. Adding fuel pressure makes your injectors flow more fuel.

 

The only thing that keeps me under 40 psi is the stock regulator diaphram. If I was to get rid of it, I would run 50 psi on 45 lb/hr 4.3 injectors. Most of the GM TBI injectors have been tested to work at 70 PSI! The point of diminishing return is when the solenoid can no longer open the pintle to allow fuel to flow.

Bumping from 20PSI to 30 PSI gave me a huge difference in the pulsewidth/DC needed to properly fuel the engine. I went from a redline (%DC over 85%) of 4,500 to a redline of 5,600 and still at only 68% DC.

It still idles at a smooth 600 RPM in Park/Neutral @ 26 MAP, with a PW of 1.2 and 3% DC.

PS-I was feeding my 258 RWHP 305 that I recently swapped to TPI with 55 lb/hr 305 injectors at 30 PSI.

 

"Bumping from 20PSI to 30 PSI gave me a huge difference in the pulsewidth/DC needed to properly fuel the engine. I went from a redline (%DC over 85%) of 4,500 to a redline of 5,600 and still at only 68% DC.

It still idles at a smooth 600 RPM in Park/Neutral @ 26 MAP, with a PW of 1.2 and 3% DC."

Impressive numbers. 26kPa is what I get on decel. My 350 is idling at 875rpm/47kPa. PW is 1.3 at 3%DC. @5700rpm, the PW is 4.3 at a 75%DC with a MAP of 96kPa.

 

mine idles at 750 at 39kpa, PW is 1.3 @ 3% DC, WOT PW is 4.4 and 78% DC, and 72 kpa.

 

The BLM of 172 is adding fuel, a lot at that. I would first add to the VE table in the idle area (MAP & RPM). And see what happens. The other side is that the BLM is adjusted according to O2 sensor feedback. Is it an AC Delco sensor? And if headers a heated sensor? This can make a difference.

RBob.

 

LC-1 Lambda Cable w/ O2 Sensor (Standalone WBO2) [Model: LC-1 w/ O2]

I got a suggestion to use this one and at $199 its the cheapest out there, how many people have tried it? And what problems should I look out for? Does it include everything need to hook up to the EBL?

 

I and at least a couple of others have had lots of success using the LC-1. Suggest you get it from one of our own and support the DIY effort - go to:

DIY Fuel-Injection Tools - Moates.Net

to order it (and no, I'm not affiliated with Craig Moates and his DIY stuff in any way -- other than another of his very happy customers)

 

It is a Bosch sensor and no, it's not heated. It is responding though, even if I just let the truck idle, the O2 sensor does get hot enough to work.

 

And you've verified that it is staying in closed loop and not dropping out? I'd still put in a heated AC-Delco 3 wire sensor (AFS-74) if it were me (and I did).

 

Yes, it stays in closed loop no problem. I may add a 3 wire O2 sensor later, but it seems as if it's not necessary.

I used to sell auto parts and I can tell you one thing about AC Delco the last few years--they don't make any parts anymore. They farm out everything. Most likely, by paying for an AC Delco sensor, you're getting a Bosch in the box.

Either way, my idle is way out of whack at the present. Everything else seems to be running real well. I'm almost to the point of buying a wideband, I think with you guy's help I've proven to myself that this tuning isn't so hard, I just need to straighten a few things out.

RBob, I sent you some data logs, please look over them and tell me what you think.

 

I should also have inquired about headers. I just assumed that the vehicle has them. It is possible that the O2 is cooling off enough to report lean. With the result of having a lot of fuel added (the high BLM).

Maybe flip the open loop idle option bit. And tune from there. If anything it is worth trying it out.

RBob.

 

I've been getting all my tuning stuff from Craig and he has been great to deal with so I see no reason to stop.

 

I'd buy that, because it does smell rich and the idle is choppy (no black smoke though).

Did you look at my data logs?

If I do force an open loop idle, where/how do I tune fuel mixture? What parameter do I edit for that?

 

Looking at the data logs there is an issue with the O2 sensor to the ECM. To me it looks as though the O2 sensor wire is shorted to something. May have burned through on the header.

The fils.dat log starts out normal. The O2 starts to heat up and come alive showing voltages in the 700-850 mV range. Eventually it is in the 900 mV range. Which on a cold engine is normal.

Then something happens, the O2 voltage starts getting funny. Such as going from 4 mV to 814 mV in one frame. As time goes on the O2 voltage sits low, with jumps to 451 mV, and back low again. See attachment.

Check the O2 sensor wiring for any burning on the exhaust or chafing on a bracket. It may also be at ths point the O2 sensor is gone. The Fils2 log doesn't show any real activity on the sensor.

RBob.

 

I'd get another o2 sensor, preferably a 3 wire. Just added the 12vdc swithed and a ground. I had an o2 sensor do the same thing and had me all screwed up. FWIW, I've been using the universal cheaper ones 'cause I was running so rich at idle when I first started tuning, it seemed to eat up o2 sensors, I went through like 3 of them till I got my tune good. Or it could have been my notorius crappy luck!!

 

Yeah, I'm planning on getting a heated one, I just want to make sure that my rings are seated first and the engine stops using oil. I don't want to eat up a brand new O2 sensor.

My VE learn work has added fuel in a lot of areas of part throttle. It doesn't seem to ever want to take fuel away.

The 02 sensor wire must be shorting on something. I'm going to have to get that straightened out. I'll probably have to solder in a new piece of wire and tie wrap it out of the way. Now that you remind me, I've been meaning to take care of that.

This vehicle is off-road use only, so it's pretty hard to get a place to drive it and tune it. I was driving it around in a new subdivision where there is no traffic to get the data that I did get.

 

Down,

Sounds like its going to be difficult getting the Learn VE to calc an accurate modifcation. As Fast355 will tell you, the Learn VE is accurate after doing a significant datalog and not sure 3-5 mile trips. My tuning has progressed much faster once I started doing 50-100mile trip for logging. I usually combine that with a trip for another reason. As you said, the car is strictly off-road, so its a problem.

 

Yes, this truck has 40" tires, hydraulic steering, no doors, etc. It's not safe or even close to legal for road use. The tuning doesn't have to be perfect for highway cruising, I just need to make sure it idles and makes good power.

All of the tuning thus far makes me wonder what this injection setup would be capable of on a road driven vehicle. There are a lot of features that are useless to me that seem like they'd really help drivability. Right now, even at the stage I'm at, my truck runs WAY better than it ever ran with a carb, and I'm very proud of myself for choosing EFI for this engine. It's not perfect yet but it'll get there.

I'm going on a four wheeling trip next weekend and I will be data logging most of the time. That should allow me to get much more information that I can use for tuning.

This truck hasn't had 50-100 miles put on it in years. It usually crawls along at 3 mph or so. The only time I really get moving is if I'm going through mud or some other surface where wheel spin is necessary. I have been taking it for short rides on the road to try to get some data though.

I understand that it's difficult, but I guess it's no different than if it was just a straight drag racing car.

 

Since you basically need Idle/Off-idle/WOT it shouldn't be too bad to tune. I wounder if you could take the 40" tires off and do some dyno tuning for power. Can you revert your setup to RWD or is it Full-time 4wd?

This is a near stock, very mild TBI 305 with tuning, prior to the EBL.

YouTube - Van Burnout

 

FAR OUT!

 

On a WOT run how steady are your WB AFR'S supposed to be? If I get them close in 1st and 2nd they change in 3rd and 4th. What could be changed to correct this?

Thanks guys.

DM

 

I have noticed this somewhat as well. Mine doesn't vary much more than .2 or .3:1. Not enough of a problem to worry me, much better than most carbs that I have put on a wideband. I am running a 700r4 with a loose converter so you 5 spd guys maybe having more difficulty than I.

This is still my main problem!

The Darts are off and back in the garage after valve guide to valve clearance issues. Need to get on Manley's case, LOL. This is with ported 193s on my engine and 61# injectors at 25 psi!

 

Chris I thought the new 350 was staying stock until the warranty ran out.

LOL......anyway how much difference did the porting give?


As far as the AFR's mine vary more than that in one gear which can be improved upon. They run from (after AE runs out) from lower 11's to high 12's. But then they are different in other gears leaving questions as to where to apply changes to correct AFR.

 

Fast,

Looks like your injectors were static on that run. Are the 200 IAC steps there to allow more air?

 

It had an issue under warrenty, as the person that installed it, GM paid me to "FIX" it. The engine broke a valvespring in the original head, bent a valve, and picked up a terrible miss. The head needed to come off and I wanted to make damn sure that it wouldn't happen again. Stock TBI springs are NOT designed to run @ 5,500+ RPM. The ported 193s gave me more compression and alot more flow. I would not hesitate to say 40-50 hp, but I have not taken it to the track or dyno'd it yet. I put the Darts on there as a temporary measure, so that I was mobile, while working with the swirl ports.

Yep, the the IAC is actually at 255 counts to allow for more air which is still at 94 KPA @ 5,000.

 

The wanting to die when decelerating to idle area (trailing throttle, surge like a tsunami) with vigorous recovery persists, I have added considerable fuel to 20-40 areas, but in reviewing logs now it seems that the lean condition is caused by the IAC remaining too open for too long.After the IAC drops to the 2-4 for idle,things are gettin rich. Is it correct to raise TF decayfilter rates and lower delay time? Dfco is disabled,should TF gain be cut as well , how about cutting Min + Max TF steps? (running 2" bores) Idle is getting quite rich with the raising of the cell values, which exposes more of my ignorance.. Would you be so kind as to elaborate on the 0 cell rpm and mph? Is there a rich limt or commanded AFR for Idle? The lean limit is cool,but how is the rich end controlled? By the ve cell only or are there other modifiers? This is all open loop stuff, but the surge problem persists in closed as well. Thanks for the info and the patience, Val

 

The Idle Cell RPM threshold is the crossover point between cell 0 & 2. Once below that RPM the ECM switches from the decel cell to the idle cell.

The Idle Cell MPH threshold is to enable BLM learn. When in the idle cell the MPH needs to be below this threshold to enalble BLM learn.

No rich limit for AFR.

As for the lean during decel, the IAC won't affect this. The air that is bypassed will affect the MAP along with the area of the VE table being used. The issue may be that the injector pulsing is changing in and out of async mode.

If it is this usually causes issues when combined with larger injectors. Check the data log and if the ECM is switching in & out of async mode, set these INJ terms to 0:

Async transition Hi
Async transition Lo

That will keep it in sync mode.

If you have a short log of this issue feel free to zip it up and email it to me.

RBob.

 

Thanks for the info, APW is 0 in the trouble areas , and seemingly everywhere else also.. If I savvy what you said, the approach should be to leave the IAC alone and increase the ve cells to satisify/match the IAC action,when I got to the point that 20-30 was higher than the 50 cells ,I was sure that just couldn't be right, but I see that if we are adding fuel to match the IAC action, it makes sense..Of course confusion still lingers on the o cell,is it a specific cell in the VE table, or is it derived from a cell and modified, not seen in the xdf? The cell numbering is totally unknown to me(more of that pesky ignorance),Thanks again for the help and the patience, Val

 

OK, sounds like it is staying in sync mode. Which is good.

when I got to the point that 20-30 was higher than the 50 cells ,I was sure that just couldn't be right
Ahh, the bathtub curved VE table, this is typcially caused by not enough injector bias. There is a table that is injector bias vs battery volts (INJ - Injector Correction Offset). It is an adder table, not the multiplier table. Add 200 usec (micro-seconds) to each entry of that table. You may need to add a little more later. You will know once the VE tale comes together after this change.

This will level out the VE table and better linearize the PW calc. What is happening is that you are adding to the VE table to make up for the injector opening time. And end up with the 20-30 columns higher then the 50 KPa columns.

The low VE areas will richen up after you add to the bias table. No issue with that, just need to be aware of it once you see that.

There are 3 BLM cells: cell 0 is used for idle, cell 1 is used for cruise, with cell 2 used for decel.

The idle or decel cell will be used when the throttle is closed. The engine RPM is used to decide whether to use the idle cell (low RPM), or the decel cell (higher RPM). There is an RPM threshold in the cal for this.

If the throttle is open then the cruise cell is used.

RBob.