CJMurray

Well it is time to start tuning my tbi 350 that a swapped into my Jeep and I'm looking for some advice on the best tuning avenue. The motor is a stock, rebuilt 350 with a Holley intake and 670cfm tbi unit. I've also added headers, true duals, and an upgrade fuel pump. It has run ok for the past year while I got mechanical bugs out, but it is bad on gas and not near as fast as it should be. Is Rbob's EBL setup the easiest and quickest route for a new tuner to get this set up dialed in or should I persue the MAF route that some others have had some success with.
I have the chip burning equipment and will be purchasing a wideband to boot. I have read nearly all the EBL threads, and I like the support you can get here. A cam and a set of trick flows are in the future, but I'd like to get my feet wet on a more stock set up. So spend my money Gentlemen!

CJMurray

Any success stories with either EBL or a MAF on a similar set up would also help. Thanks

dimented24x7

iTrader: (2)

The major advantage of the MAF setup is that its immune to the fuel dynamics issues that come up at part throttle with a wetflow (gas in the manifold) system. At low throttle, the fuel cools the intake charge, and can throw off the speed density calcs. MAF sees the flow, which means that itll accuratly calculate the fueling with as little as a few tenths of a percent of error. The MAF is also faster to tune as the only table controlling the fueling is the table that relates the MAF output to the gms/sec airflow. Even with an airgap manifold and a cold air intake, Ive found the system to be quite versatle. The car runs fairly well even at very cold temps with a cold engine. Performance is also good. With a few hours of tuning, I was able to get a smooth running engine and the car can do 0-60 in a little over 5 seconds.

The main disadvantage is that you have to be careful when setting up the intake as the MAF is sensitive to airflow. Any resonance and the fueling will go all over the place. Also, its based on a later model PCM, so the routines are more complex. Its not super hard to set it up, but there will be a learning curve, and its not as intuative as other systems. EBL will be more intuative, but is speed density (MAP controlls the fueling), and costs money.

The MAF system is free. I dont think I could charge anything, anyway, especially if I included the transmission code. Much of the algorithm was, and still is, patented by GM.

CJMurray

Obviously, to do the MAF swap, I would need an MAF sensor and the correct computer. I would also have to set up a different intake to utilize the MAF. But, would I have to modify my harness to use the newer ECU? And when I did get the hardware installed could I just start it up and start data logging? I'm currently using a 700r4 set up, so other than the TCC set up, I wouldn't have a lot to modify there. Thank you for the input!

dimented24x7

iTrader: (2)

Youd need: Laptop, OBD-1 cable (bought or home-made), 32 pin red + blue connectors + pins, 96+ MAF sensor, wires. The connectors and pins can be had from rosesandwrenches.com. Youll need to repin the ECMs connectors. This is about a 1-2 hour job. You basically depin the old connectors and insert the pins into their respective positions in the new connectors. Run power and signal wires out to the MAF, and the installation is complete. The pigtail connector for the MAF is available through A/C Delco.

As for setting up the PCM, there is a thread in the stickies on the TBI board that covers the basic installation. There is also a thread on this board for setting up the TCC.

dimented24x7

iTrader: (2)

Heres the thread referring to the non-CC TCC.

https://www.thirdgen.org/forums/diy-...700r4-tcc.html

CJMurray

Thanks for the input! I'm scared to jump in with both feet as I'm new to tuning, but I guess there is no other way. I'm an engineer with a little patience, so I should just take the leap. I know you and Fast have had success with this set up, but were you using your modified .bins to get you started, or did the stock bin get you up and running? Also, do you or Fast have the re-pin diagram available? Thanks for the input. It would really be nice to have some one do a step by step swap from hardware to software, but I was hoping not to be the dope to attempt, lol.

RBob

iTrader: (1)

There are pro's & con's of both systems. Both will cost money, so no free lunch there. Fastest & easiet to set up? The EBL. It is an integrated package: BIN, ECU/XDF files, documentation, data logging, VE Learn, ADC inputs for WB and other devices, playback and analysis of data logs. All the pieces that make it easier for the novice.

Uses stock TBI ECM harness such as used in f-body's, b-body's, and a bunch of trucks. Has TCC controls for the tranny and a bunch of other goodies. If running on-board air or welding, has a high idle input to bump the engine speed up. It is well worth the price of admission.

RBob.

CJMurray

Rbob, I do like the straight forwardness of your EBL. I agree with you on the price as well, especially since time is money. I'm just curious as to how superior MAF is to a MAP system, especially with my set up. I see the benefits of MAF, but I'm just looking to get my set up dialed in and then forget about it. I do have to pass emissions here in MA, but I believe this is a sniffer test only and visual is not as important. My major concern with MAF is that I'll spend so much time setting it up and debugging, that by the time the top down weather gets to New England my Jeep will be layed up in the back yard and I'll be kicking myself.

CJMurray

Anyone run both? We've heard from the people who know these systems best and their continued support is surely appreciated. What are the pros and cons? How long are you guys spending on a semi stock tune? I'm looking to upgrade the heads and cam in the future, but let's be honest... it isn't worth the money if I'm not going to tune it properly.

RBob

iTrader: (1)

One of the better items for driveability and ease of tune, is to run a heated intake manifold. The stock TBI intake has a water jacket under most the underside. On carb style intakes I'll block the exhaust x-over's, then run water (coolant) through that area.

RBob.

CJMurray

I believe the Holley TBI manifold I'm using is heated. As I've stated before, I do drive my jeep and it drives reasonably well It run's pig rich when cold, seems to break up occassionally in higher rpms at WOT and simultaneously seems to bog down low. Obviously the Holley tbi unit is the culprit here, but I want to have my cake and eat it too.

dimented24x7

iTrader: (2)

Theres not much debugging with the MAF. But, like EBL, it needs to be calibrated to the engine its running on. As for the intake, youll either need to use a stock type airbox with a non-uniform cross section, or a cone filter element on the end of the MAF if you dont mind taking in hot air. From what Ive found, getting the car up and running takes about two or three hours of tuning. Dialing in the fueling takes about 30 minutes (advantage to using MAF) and its done. You do a couple runs with a wideband to calibrate teh sensor and adjust the MAF table to match what youve datalogged. The frequency based MAFs and 32 bit software code are very precise. If the curve is correct, it delivers the desired AFR within 2% over all operating conditions. Fast was using a late model MAF and it worked without issue off the bat as the table for the MAF was for that specific one. I used an earlier unit, and had to calibrate to its specific output curve. Then its the timing, which works in the same manner as EBL and other systems. After that, its a matter of details like idling, initial start and cranking parameters, etc. Those are usually what take time as there are alot of components to the parth throttle/startup/cold engine calibration. It does provide very good drivability, and allows the use of hi-po manifolds in nearly any condition. My engine has a misground cam in it and idles like complete crap. Very erratic and lumpy, sort of like a blown head gasket or an ignition problem. If the PID idle speed control algorithms are enabled, it almost idles perfectly. Its pretty amazing what the newer algos can do.

if you want a versital system that can adapt to almost all conditions without the need for recalibrating, and provides good drivability, the PCM + MAF are for you. With the MAF, theres almost no drift in fueling with varying conditions and the AE routines can adapt to the manifold wall temperature to provide the correct AE with non-stock, non-heated manifolds.

If you want a system thats easier to use and provides additional features for out here and you dont mind having to tweak it every now and then EBL is for you.

dimented24x7

iTrader: (2)

Fast355 would be the one to talk to. hes used my system as well as RBobs...

dimented24x7

iTrader: (2)

The thing I hate about the heated manifolds, in addition to the heat, is that they dont flow well and the plenum is the size of a matchbox. I wish someone would make a high performance heated manfold.

A full cold air setup that flows well provides a very nice power gains. I remember the first time I hit the gas with a cold air intake. It really boosts the power. Not just a few extra HP, but something thats immediatly noticable. The downside is that tuning the AE for one of these in the winter is like balancing a pin on its head while its resting on the edge of a razor blade. That, and the manifold turns into a block of ice. But all that extra power...

CJMurray

Well Dimented, you make a strong argument for MAF. Does the stock .bin have to be modified to use an MAF or was this a built in feature. I love the responsiveness in my vortec (MAF) truck. Does the MAF basically use only the incoming airflow to calculate fueling? Would this make cam swaps smoother?

dimented24x7

iTrader: (2)

The MAF system is comprised of open source code I wrote thats burned onto a prom and installed in place of the stock chip. The code has software that uses the MAF to calculate teh needed fueling. Teh only table for the fuel is an 85 line table of airflow vs. frequency. Through the magic of math, the computer takes teh average grams per second airflow over one complete intake cycle and calculates the mass of air in that one cylinder, and using the desired AFR, it calculates the pulsewidth for teh injectors for the next cylinder. This makes cam swaps easier as there is no tuning other then the usual tweaks to the timing and such for the cam. The only caveat is that if there is a large split in the ammount of airflow from one intake cycle to the next, youll likely get a lopey idle from the erratic signal. With EFI cams, you should have little issues.

Youll need: a PCM, MAF, connectors, 2-transistor cable, and G1 adaptor + burner from moates.net

For general tuning youll also want: A wideband and an emulator for real time tuning.

If you dont want to lock yourself in, you can make an adaptor that will allow you to maintain your wire harness as is. You can take the large connector head (the thing that the connectors plug into) out of a junk TBI ECM and use that along with teh PCM connectors to make teh adaptor. If you decide that you dont like MAF for this reason or that, you can pull the PCM + MAF, ebay it, and put EBL or whatever in.

RBob

iTrader: (1)

Heated high performance manifolds are easy to come by. Use any carb manifold with a x-over and use it for heat. A poor choice for a MAF, MAP, or CARB street car is an air-gap style manifold. There just isn't any driveability.

There are many successful speed density (MAP) installs with TBI. It works and works well. Note that GM has never used a MAF setup with a TBI. All are speed density.

RBob.

CJMurray

Well I respect both Rbob and Dimented's opinions and work. I guess I just need to check the bank account and figure out how adventurous I'm feeling these days. Thank you both for your input. It's guys like you that make this one of the best boards I have followed.

Fast355

iTrader: (2)

I HAVE used both systems.

Don't get me wrong the EBL is a fantastic product, but as far as set it and forget it. The MAF setup is on top. I've swapped cams, heads, intakes, as well as really upped the injector flow and haven't even had to touch the MAF calibration that is actually from a stock 5.3. All I had to do was tweak the AE, timing, and idle speed. The ZZ4 cammed 350 TBI with ported vortecs is a complete animal when the pedal is mashed, yet runs easily around town. It is knocking down 18 mpg highway in a 5,300 lbs Chevy G20 Van.

This is really a testament to how well the MAF setup runs on a cold morning. It was approximately 20*F outside.

http://youtube.com/watch?v=FmS1m3zlqHo

You can hear the nice ZZ4 cammed cold idle in this clip

http://youtube.com/watch?v=wRehD8He18E

Finally this is how the cold engine responds, engine probably wasn't even at 60* yet, so its a little sluggish.

http://youtube.com/watch?v=p2kH39oC8O0

CJMurray

Thanks Fast, did you use a stock 5.3 MAF sensor as well? Also, I know you and Dimented have changed some of the original pin out locations, would you or anyone have a diagram for the swap. If I did do this, I would probably make an adapter to keep my original harness plug.

Fast355

iTrader: (2)

The MAF is stock for a 2002 5.3 Suburban, I got the pigtail and the sensor for $25.00 from a local wrecking yard. The duct work was found inexpensively as well. The TBI bonnet is from an early 90s FWD V8 Cadillac TBI.

I can find my notes on the pinout change. It is pretty straight forward. When I find my notes, I will scan them and post them up. Might be Sunday before I have a chance to do so.

The Knock sensor will need to be replaced with the 1993-1996 TBI 350 equivalent.

The ESC module will need to be eliminated and the wiring jumped to connect the Knock sensor straight to the PCM.

In the process this gives you a Keyed power wire and a PCM connected ground wire to power the MAF from. You will also be eliminating the EGR solenoid at the same time, which gives you a great signal wire back to the PCM from the MAF.

The MAF sensor that I am running has 5 pins total and houses an internal Intake Air Temperature sensor. That sensor requires an extra 2 wires to operate, but IMO is well worth having and enabling.

CJMurray

You guys have sure done your homework. It seems like the initial set up is relatively straight forward: Add MAF sensor, Change KS and rewire, and make a harness adapter or repin. I would then have to get the modified .bin from dimented and then start her up. If I got a 5.3 MAF, would I have to fool with the MAF tables, or would it be straight to AE, idle, and wideband work? If I can get this thing close to as responsive as my stock vortech truck, I'd be happy. I know the motor will never run to it's potential without a good deal of time invested into tuning it. Thanks for all the input.
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So the EGR is eliminated when going to MAF? Will this cause any emissions issues?

dimented24x7

iTrader: (2)

I drove the car for a few weeks in jan/feb when my daily driver was down for major repairs. With tuning, the car worked fairly well. My only complaint was low speed (<800 RPM) leanout for the first five minutes of operation. The commanded AFR would be on target untill the engine speed dropped, and then it would lean out and the reported AFR would head to the lean end for a few seconds and then recovers. Never had any stalls. More of an annoyance problem with a stick. The biggest detriment isnt drivability, but getting the drivability. This required AE routines that can compensate for manifold plenum temp.

My biggest concern isnt as much drivability as what the emmissions are. I suspect that the fuel mixture is more heterogeneous and could give rise to excess HCs and NOx if you smog the car in the winter.

MAP setups work fine for power as well as anything else. My biggest issue was when I got away from the stock setup and used the vortec carb manifolds and cold air intakes. The fuel dynamics would rear its ugly head and the car would run different day to day at part throttle. One of the biggest reasons that GM didnt use MAF may have been reliability. Every 6 months to a year the MAF sensing elements need to be cleaned due to the large ammount of varnish that TBIs have.

dimented24x7

iTrader: (2)

Its hard to say what will and wont need to be changed. It could just be a few things. How far from stock you are will likely dictate what has to be changed. I had to touch on everything in the calibration to eliminate the various issues that popped up. I think you can get it to run fairly well. The better you want it to run, the more time will need to be invested to calibrate all the little things. Drivability is alot of detail work from what Ive experienced.

I think youll do ok without the EGR. The EGR input is currently for an electric cool. fan. I got tired of the stock fan switch so I put code in to control the fan to the set points I wanted.

CJMurray

Dimented, is the MAF table the only thing you've added to the code? I guess I'm curious if I could follow the threads that detail tuning this particular PCM for things such as AE and idle and so on. I'm afraid that if the .bin is so far modded from the original, I will be pestering you and Fast for guidance on a daily basis. As a new tuner, I'm sure there will be stumbling blocks, but I don't want to be that guy with the crappy jeep that is PMing you daily, haha.

dimented24x7

iTrader: (2)

From the main fuel tuning perspective, yes. Ive also made changes to the AE routines. The main AE is handled by the MAP while the short AE needed for any delays in the MAFs response as well as manifold filling is handled by the TPS AE. Ive added other odds and ends as well as deleted code for the EGR, governor, air, etc. Ill post a list of the commonly used items that I have in my tunerpro def. file.

The MAF handles the fueling with SD serving as a backup. If the MAF pukes, you can unplug it and continue on in speed density mode.

The actual MAF code is comprised of a frequency read in subroutine in the DRP interrupt routine, 16 bit table lookup subroutine, and a 32 bit calc. routine to compute the needed pulsewidth.

CJMurray

So MAF TBI truly is your own evil creation! Very nice. I'm surprised more people aren't running it.

CJMurray

Well, the arguments are so good for either system that I may try both!! I'm thinking that I will throw the EBL system into my Jeep for now and possibly try the MAF route on another build up my cousin is working on. He is still putting together his motor and car, so it really will be of no extra expense to go the MAF route there. Thank you all for your help and support.

dimented24x7

iTrader: (2)

Heres the pinouts as well as the list of common items for reference, if you so choose to use the system. The hadwritten lettering cooresponds to the current pins in the stock harness.

dimented24x7

iTrader: (2)

Fast,

BTW, is your brother still using the MAF TBI in his work van? If so, hows that been working out over the long run?

CJMurray

Any reason why I couldn't open the .zip? It said it was not valid.

dimented24x7

iTrader: (2)

Try firefox or another computer if its available. Some versions of e-explorer wont DL the zips properly for some reason.

CJMurray

Well I'll be damned, Firefox worked like a champ. What is the text file you included. Is that a print out of your current setup? Good info as I've been scrolling through, just curious where it came from. Sorry for the newbie questions.

dimented24x7

iTrader: (2)

No problem.

Thats the printout from TunerPro. Those are common items that are in the tuning definition file that Im using. Below each item is the constant or table thats currently entered in the bin.

Those items actually appear as selectable items in tuner pro. Click on something like the injector constant or the maf table, and itll pop up in a window for editing.

Blazin4x4

Is there a reason why the ebl can't be used with the maf?

Fast355

iTrader: (2)

The high mileage 4.3 TBI is still running great. The 700r4 is starting to slip though. Really wanting to start messing with the transmission side of the code to run the transmission off the optical VSS and put a 4L60E into it. We've got a 4.3 Vortec longblock sitting in the garage to cam, go through, and run.

dimented24x7

iTrader: (2)

The MAF requires a pulse accumulator (counts the electronic pulses from the MAF) and pulse counter (stop watch that measures the elapsed time between MAF pulses). This didnt become available until 93 with the advent of the PCMs, and to my knowledge, is still the same stratagy used today.

I did make a system for the earlier TBI computers, but it required a frequency to voltage converter. On top of this, unlike the PCM which can read the MAF frequency in with 16-bit precision, the ECM could only do the voltage at 8-bit through the A/D. This resulted in poor resolution. This, and the early motorola 6809 is missing some key features like the DRP driven interrup and FractionalDIVide and IntegerDIVide, which make the fuel calculations in the software much easier.

Oddly enough, Im not the first one to do this. I was looking on ebay and I ran across an old fuel injection system made by airsensors, inc. in the mid 80's. Its a real dinosaur. Only compensation was the CTS. No TPS, IAT, MAP, or anything else we normally take for granted. Just an accel type TBI, MAF, and a CTS. The adjustability was confined to 5 pots on the front of the unit and it used one of the spark plug wires for syncronous injection if you wanted it. Async if not.

http://www.auto-nomics.com/documents/HR_0285.pdf

"Code Buster" bit is also interesting...

Fast355

iTrader: (2)

That supercharged 4.3 with the air sensors EFI would be a fun little, fuel efficient powerplant.

dimented24x7

iTrader: (2)

Reman. analog systems are still avaliable... And they have the temp sensor Im looking for to boot.

junkcltr

iTrader: (1)

I like it. Anything with boost if fun. You get the best of both worlds. Great MPG and HP. Are you going to run the SC setup with the 395/427 PCM?

Blazin4x4

yeah but the savings from the great mpg gets eaten by the price of premium gas. I am looking into buying a 98 or so ls1 trans am and I was all stoked because they get 28 mpg hwy with 350 fw hp then I realized their 10:1 .

dimented24x7

iTrader: (2)

Yeah, anything these days with alum. heads that NA has around 10:1 CR.

Dave Farr

I haven't pulled the trigger yet on a ecu mod. Dealt with RBob- great guy full of relevant info. I feel my application doesn't require a full blown stand alone but will do it if I have to. Application is 1989 Chev 1500 4x4 350, TPI/Vortec heads 700r4 all running off 7747. Started life off as TBI then went to Edelbrock MPI conversion then onto TPI and never was satisfied with how the chip was programmed. Was going with Perfect Power SMT 7 as you can piggyback the 7747 and run a wideband in closed loop- but my dealer is getting cold feet about using it for whatever reason. Motec is pricey- considering Haltech- reliablility is paramount. Future engine mods include warmer cam, RHS 2.02 Vortec heads. The EBL looks good, I very interested in the MAF mod (MAT is present but unconnected right now), my mechanic made this suggestion also. Dimented24x7 whats the price of admission including all parts needed. Really wanted to run the wideband but this is not looking good. My email is davefarr@telus.net PS I'm working abroad and will have an experianced tech doing the work- wanted to stay away from chip burning and do all tuning via laptop. Thanks

RBob

iTrader: (1)

I just haven't written the code to use a MAF. Still not a big fan of MAF systems.

RBob.

dimented24x7

iTrader: (2)

What reservations do you have?

The newer MAFs are lightyears ahead of the old bosch garbage systems. Theyre no longer an overly complicated POS. GM has these things down pat now. The control circuits are now housed along side the main body in a small nylon resin housing. All thats in the sensor is just the elements. Theyre also easily serviced, and seem to be reliable. The one I have is 10 years old and still works well. The interface is also much easier. Just power and signal. The only thing is that you need to either have the correct hardware or an A/D converter, which adds complexity and cost, but works ok provided you have a 10-bit A/D. From my experience, 8-bit systems dont cut it due to the resolution needed, which means that youd need external hardware or something with a C3 ECM.

dimented24x7

iTrader: (2)

The price of the MAF software is free as its open source. The cost of the PCM, MAF, G1 adaptor, MAF, will probably run about 150-200 total, depending on what deals you can find at the yards.

Like most of GMs other OBD-I systems, it still has the memcal and chip. There is an input for a wideband, but its currently just to have its output in the datalogs. True full scale wideband control would be more difficult due to the poor resolution of the 8-bit A/Ds. The MAF is good enough that itll be fairly close without closed loop control at WOT. From my experience, the actual AFRs within +/- 2% of what your calling for as long as the maf table is correct. It still has the narrowband for P/T closed loop fueling.

Dave Farr

I'm sorry, I had the impression that you sold conversion kits.

Dave Farr

Rbob, I see that you got around to include the EGR in your package, how would a combination of MAP and MAF work with EBL?

Blazin4x4

I dunno... I'm torn. I want and ebl and maf not one or the other. Ebl makes things so much easier but so does maf...