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Factory FI tuning

Bent77

Bent77

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Who out there is still tuning factory fuel injection?

@dyeager535 @sreidmx @az_762_nato @bigblock72

Looking to data log and tune on a 7747 computer with possible move to 7427
Hoping a new and up-to-date thread with the following information:

1) Tuner software platforms and their good and bads
2) links to hardware and software

Thanks in advance. Hopefully some life can be brought back to this tiny corner of the forum


Please tag anyone who is still data logging or may want to be a part of the conversation
 
Yep, still here. Haven't done a lot of tuning the last few years, but I probably should get back in and make sure the new motor is as happy as it seems to be.

For the "dinosaur" OBD1 stuff like we are dealing with, if there is anything new out there I wouldn't be aware of it. I don't know how well EBL ("embedded lockers"?) caught on, but as I recall it required some hardware modification of the ECM? And megasquirt was getting better last I had heard, but haven't kept up on it. I disliked megasquirt because initially it didn't support timing. Pointless IMO, that's me.

Only other option I am aware of, and what I use, is Moates.net APU1 ( http://www.moates.net/apu1-autoprom-package-usb-version-p-54.html?cPath=64). Seems pricey but just checked my email, paid the same in 2010! Moates' hardware for OBD1 stuff is here http://www.moates.net/gm-19851995-c-64.html

For software, I use http://www.tunerpro.net/ Mark Mansur is a great guy, if you end up using his software I'd certainly recommend donating to him. Get the "Pro" version, it's fully functional whether you pay or not. You can load it up on your computer and check it out for free. Heck, you can use it for free too, but it's nice to recognize someone that put this much effort into something this useful.

For the TBI stuff IIRC you need to solder a socket into the ECM to be able to hook up any cables and/or the chips you burn.

I recommend the APU1 because you can run the vehicle off of it...do not discount how tedious learning how to burn chips is going to be. With Tunerpro running on a laptop (maybe phone? Not sure if that is possible) and the APU1 hooked up to the OBD port and the ECM PROM socket, you can drive the vehicle, datalog, AND make changes to the tune with the vehicle still running, all from the laptop. When you are satisfied with the tune, you use the APU1 to burn the data to the PROM (SF512 IIRC) insert the PROM into the ECM, and that's it. You do not need to have the APU1 hooked up to a laptop or the data port to run the vehicle, so if you have to stop programming, and need to use the truck, you can just stick the APU1 somewhere and drive. Not ideal if you are going to go beat on the truck, but if you need to use the truck for something, certainly possible. I've done it multiple times.

There is of course a lot more to this, but it's GENERALLY not complex. I'm not super up on tuning TBI, although much of it is similar to TPI, and the way Tunerpro and the APU1 work is nearly identical for either one. The complexity comes in understanding everything within the programming.
 
dyeager535 said:
Yep, still here. Haven't done a lot of tuning the last few years, but I probably should get back in and make sure the new motor is as happy as it seems to be.

For the "dinosaur" OBD1 stuff like we are dealing with, if there is anything new out there I wouldn't be aware of it. I don't know how well EBL ("embedded lockers"?) caught on, but as I recall it required some hardware modification of the ECM? And megasquirt was getting better last I had heard, but haven't kept up on it. I disliked megasquirt because initially it didn't support timing. Pointless IMO, that's me.

Only other option I am aware of, and what I use, is Moates.net APU1 ( http://www.moates.net/apu1-autoprom-package-usb-version-p-54.html?cPath=64). Seems pricey but just checked my email, paid the same in 2010! Moates' hardware for OBD1 stuff is here http://www.moates.net/gm-19851995-c-64.html

For software, I use http://www.tunerpro.net/ Mark Mansur is a great guy, if you end up using his software I'd certainly recommend donating to him. Get the "Pro" version, it's fully functional whether you pay or not. You can load it up on your computer and check it out for free. Heck, you can use it for free too, but it's nice to recognize someone that put this much effort into something this useful.

For the TBI stuff IIRC you need to solder a socket into the ECM to be able to hook up any cables and/or the chips you burn.

I recommend the APU1 because you can run the vehicle off of it...do not discount how tedious learning how to burn chips is going to be. With Tunerpro running on a laptop (maybe phone? Not sure if that is possible) and the APU1 hooked up to the OBD port and the ECM PROM socket, you can drive the vehicle, datalog, AND make changes to the tune with the vehicle still running, all from the laptop. When you are satisfied with the tune, you use the APU1 to burn the data to the PROM (SF512 IIRC) insert the PROM into the ECM, and that's it. You do not need to have the APU1 hooked up to a laptop or the data port to run the vehicle, so if you have to stop programming, and need to use the truck, you can just stick the APU1 somewhere and drive. Not ideal if you are going to go beat on the truck, but if you need to use the truck for something, certainly possible. I've done it multiple times.

There is of course a lot more to this, but it's GENERALLY not complex. I'm not super up on tuning TBI, although much of it is similar to TPI, and the way Tunerpro and the APU1 work is nearly identical for either one. The complexity comes in understanding everything within the programming.
Click to expand...
Will the tuner pro read through the OBD directly to a laptop?
 
Bent77 said:
Will the tuner pro read through the OBD directly to a laptop?
Click to expand...

I haven't run just the ALDL cable in a long time, but I think so...I'm pretty sure winALDL will if TunerPro won't. But I'd certainly work with TunerPro over winALDL if I could.

That's why I recommend the APU1, if you don't already have some components....buy a cable, then buy a chip programmer and the chip sockets, the chips, etc. The APU1 pretty much puts everything in one bundle to get you going. Except I think you will still need to work around the chip socket issue with TBI.
 
I’m at definitely going to start with the cable and data log and go from there. Currently my issues is I’m messing with the fuel pressure, and am going to the 670 cfm throttle body.

Then when I swap the engine I want to see how close the baseline is. Duration and compression wise they are very close
 
Smokinthehippies said:
All I can think of when I see these threads is that it sucks that eagle mark is no longer with us.

Doesn’t help the tuning you’re working on but I think of him every time.
Click to expand...
He was the man. Big loss on all fronts, was a decent guy on top of being a whiz
 
Can't really go wrong datalogging. The '747 sucks with it's 160 baud data rate, but it's better than guessing. :)
 
One thing I would remind you of is the cost differential between the chip burning tools etc and the capabilities vs the MegaSquirt, for your needs a 250$ and some solder time or a 450$ for the assembled MS2 should do whatever you ask it to do. Timing, injectors, fuel pump, fans etc.. EDIS or coil on plug.. there is almost no limit, but the other consideration is it’s real time tuning and logging capabilities are far greater and far higher resolution than the gm obd1 stuff.. so when trying to find a problem you will have more data to reference. Also it is adaptable to other hardware gm based of course, if you decide to change to another style injection or throttle body.
There will be learning curves for both, I just think the MegaSquirt community has a wider range of guys, and they don’t have to be Chevy guys to help with whateve prob you are having..
 
Does that come with the software as well? I see reference to "Megatune", I assume that is how you program it?

If it is complete, that would seem to be a pretty decent way to go. Doesn't seem like it's much more than getting setup for TBI chip burning/datalogging, and I can only guess to say that it's a better setup. The baud rate certainly is, which is one of the real limitations of the '747 ECM. Nice that the MS2 will also accept WBO2 input, that might mean you could run the late model OEM sensors, which are pretty cheap?
 
Still do a fair amount of tuning myself, trying to get everyone out of the 7747 computers as they can be challenging to get right especially on a nonstock motor i.e. larger cam, larger throttle body, larger intake. Trying to datalog with 160 baud is like running an obstacle course under strobe lights. Some manual trans trucks are a complete joke to get right if not impossible.

The 7427 style computer is pretty straight forward to swap in and is so much easier to tune and datalog, they can run a 4l60/80 trans if needed plus they soooo much more refined.

I use a APU1 from Moates.net and have since 2005, I like it a lot. I don't use most of it's capability since the 7747s aren't very stable when using the emulator (a socket booster helps I've heard) and I use one of my scan tools to datalog. The APU1 does a great job logging, it is just easier for me to grab a scan tool than a laptop. Tunerpro is the best/easiest/cheapest software for tuning chip style computers that I have used, it integrates with the APU1 perfectly to burn chips, emulate and log.

Honestly though with the recent advances in bolt on fuel injection kits that can be had for under 1,000 dollars chip burning is almost a moot point. When you start adding up the costs of a burner (150-330) a bigger throttle body (200 ish) the cost of misc parts (100-300) you can easily approach the cost of a bolt on kit. Plus the time it takes to modify the computer for a 27fs512 chip, and all the other issues that always seem to come up. Unless you really want to learn it really just doesn't make sense.

The EBL systems are about the cost of a good chip burner and they are only just a little more capable than a 7747, they are a little easier to tune though.

The megasquirt computers seem pretty appealing to me especially if you already have a larger throttle body or want to go port injection or boost. The price is good and they have a lot of expansion potential. The MS2 can't run a wideband by itself but wideband gauges and drivers are pretty affordable and will send the signal to the computer. The megasquirt can be somewhat self tuning but still require a fair amount of adult supervision. The megatune software is free and the support forums are very complete with a lot of base tunes for just about every engine ever made. If you are interested in this type of computer make sure and look at all of the options especially the microsquirt.

Whatever you do don't spend any money without looking at the systems from Holley and Fitech, they work well and there a lot of things you can play with in the software that will give some tuning experience.
 
I actually had a Fitech and returned it. Some of the end users are having what seems to me as a higher than acceptable (to me) failure rated of hardware and component failures. Obviously difficult to separate user error vs component failure.

But with some intent I hope to at least give the TBI a decent whirl. The chip I am currently running is really close for the compression/cam/intake changes I have. At 17 psi I think I am getting too much fuel pressure using the EP381 and its high flow rate (little erratic at idle, but it seems to retuning some of that out). Having said that, it pulls clean to 5600. (with the small bore TB)

Doing some readings to measure how close it is to 14.7:1 is my goal. I might be able to tune the rest just on the fuel pressure based on how close it is running now.


Would I go aftermarket EFI? Possibly. But I don't think I am leaving too much on the table to be honest
 
If all you want to do at this point is look at some stuff, then an ALDL cable and Tunerpro is pretty painless. OBD1 is just getting so long in the tooth with all the aftermarket (and LS) advancements, it's not going to get easier to deal with, it's going to get worse. Things will start to get more expensive (real 512 chips are no longer made, all remaining are NOS or Chinese ripoffs that don't work right) and there will be less people to help with it. Unfortunately.

But check ebay for an ALDL cable. Years back I made one, but it was a mess, if nothing else. It worked, but that's all I could say of it. For what they can probably be bought for now, probably a better idea to just buy a cable.There was a guy over on gearhead-efi that was making and selling the cables to help support the site, no idea if he is still doing that.

One other option, which I don't think is nearly as functional as being able to log while driving like TunerPro will allow, is an AutoXray XP240. Or maybe a newer variant of the same thing, but not stupid expensive. The 240 isn't real capable, but in terms of data useful for what you are talking, I *think* it will show BLM's, and maybe AFR (which is near worthless except for steady state cruise on flat ground). They should be about $10 now. Only partially joking about the cost. I have one, I should probably get rid of it, the market is probably pretty small for them now. I used it on a Ford (not mine!!) once, and very early on with the TPI setup, but once I paid for the APU1 and started using TunerPro, I had no real use for it. I needed to actually tune my setup, not just watch what it was doing.
 
Looks like some of the A/F meters we were talking about will also data log

But certainly trying not to spend $1k to support a 7747 computer
 
Bent77 said:
I actually had a Fitech and returned it. Some of the end users are having what seems to me as a higher than acceptable (to me) failure rated of hardware and component failures. Obviously difficult to separate user error vs component failure.

But with some intent I hope to at least give the TBI a decent whirl. The chip I am currently running is really close for the compression/cam/intake changes I have. At 17 psi I think I am getting too much fuel pressure using the EP381 and its high flow rate (little erratic at idle, but it seems to retuning some of that out). Having said that, it pulls clean to 5600. (with the small bore TB)

Doing some readings to measure how close it is to 14.7:1 is my goal. I might be able to tune the rest just on the fuel pressure based on how close it is running now.


Would I go aftermarket EFI? Possibly. But I don't think I am leaving too much on the table to be honest
Click to expand...


There has been some minor issues with the fitech systems, injectors and sensors mostly but all are easily repaired. The real issue was there lack of support in the first year, simply growing pains. Their fuel pump system is a big POS for sure. I put a system on last month and one of the injectors went bad in the first 100 miles, 5 minutes on the phone and they had a part in the mail. I had the part in my hand 48 hours later, it took 10 minutes to install the injector. Some of the factory settings are a mile off so cold start is a big issue on all of them I've installed, I now know the settings that work pretty good and I don't have to mess with them.

If you still have a small t-body you are leaving 20 horsepower on the table easy. I don't think I've ever seen a mail order chip or a canned tune be more than in the ballpark. There is power and drive-ability on the table for sure. If the cam is bigger than 215* @ .050 then it probably needs open loop idle. I install ep381 pumps in all of the tbi trucks I work on even when they are stock and have never had an issue, they only move about 35 GPH and the stock regulator seems fine with it. Your erratic idle is probably due to an overly rich idle (most canned tunes seem to have that issue) and the BLM numbers are probably near their lower limit (around 90). 7747s do weird things when the BLMs get low. Again open loop idle helps eliminate those issues especially when the idle map readings are higher than 35-40 kpa. Once you get a bigger throttle body and do some tuning you will be right with aftermarket stuff for sure. I think you need to order a Burn 2 from moates (85.00) and an ALDL cable (60-80ish), download tunerpro rt and get to work. I can show you how to modify the computer to take a 27sf512 chip for less than 5 bucks as long as you can solder a little, just let me know before you place your order to moates and I can help you get everything in one shot.

I would recommend a wideband gauge of some sort, especially for tuning WOT. You will find that your air/fuel ratio will be steady at 14.7 once in closed loop, you need to be looking at BLM and INT numbers to know how much the computer is adding and subtracting to know how close the VE table is.
 
bigblock72 said:
There has been some minor issues with the fitech systems, injectors and sensors mostly but all are easily repaired. The real issue was there lack of support in the first year, simply growing pains. Their fuel pump system is a big POS for sure. I put a system on last month and one of the injectors went bad in the first 100 miles, 5 minutes on the phone and they had a part in the mail. I had the part in my hand 48 hours later, it took 10 minutes to install the injector. Some of the factory settings are a mile off so cold start is a big issue on all of them I've installed, I now know the settings that work pretty good and I don't have to mess with them.

If you still have a small t-body you are leaving 20 horsepower on the table easy. I don't think I've ever seen a mail order chip or a canned tune be more than in the ballpark. There is power and drive-ability on the table for sure. If the cam is bigger than 215* @ .050 then it probably needs open loop idle. I install ep381 pumps in all of the tbi trucks I work on even when they are stock and have never had an issue, they only move about 35 GPH and the stock regulator seems fine with it. Your erratic idle is probably due to an overly rich idle (most canned tunes seem to have that issue) and the BLM numbers are probably near their lower limit (around 90). 7747s do weird things when the BLMs get low. Again open loop idle helps eliminate those issues especially when the idle map readings are higher than 35-40 kpa. Once you get a bigger throttle body and do some tuning you will be right with aftermarket stuff for sure. I think you need to order a Burn 2 from moates (85.00) and an ALDL cable (60-80ish), download tunerpro rt and get to work. I can show you how to modify the computer to take a 27sf512 chip for less than 5 bucks as long as you can solder a little, just let me know before you place your order to moates and I can help you get everything in one shot.

I would recommend a wideband gauge of some sort, especially for tuning WOT. You will find that your air/fuel ratio will be steady at 14.7 once in closed loop, you need to be looking at BLM and INT numbers to know how much the computer is adding and subtracting to know how close the VE table is.
Click to expand...
All good stuff to know. I do have the larger TB and and going to put it on. I think the ep381 with the 18 psi spring is just too much, especially since the restriction of the factory fuel lines is no longer and issue (-6AN lines now)

I’ll do some homework
 
@Bent77
If you are interested in learning and tuning your own chip........I have the moates Burn2 chip programmer, 7747 computer with the soldered in G2 socket to accept 27sf512 chips, along with 3 chips, and the ALDL cable. I don't need it any longer since I'm going with the 454 Vortec engine. I would make you a great deal on the set-up if you're interested. Just let me know.
 
wheels87k5 said:
@Bent77
If you are interested in learning and tuning your own chip........I have the moates Burn2 chip programmer, 7747 computer with the soldered in G2 socket to accept 27sf512 chips, along with 3 chips, and the ALDL cable. I don't need it any longer since I'm going with the 454 Vortec engine. I would make you a great deal on the set-up if you're interested. Just let me know.
Click to expand...
Thanks, and I’ll keep that in mind
 
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