Jeep 7747 Conversion

**PJG1173** · 06-04-2012

[QUOTE=EagleMark;10603]I'll look at it in AM but 5.7L injecotrs on a 4.3L engine...

and your lean? [QUOTE]

Yes, when I first put the 5.7's in my 4.3 I set the flow rate at 61# and was globally lean at 13psi. I had to lower the flow rate to 58# to get it to richen up.

**EagleMark** · 06-04-2012

He does not have that option in a 1227747. Just BPW. I just looked and 5.7L BPW is 135. 4.3L BPW is 181 !

Not sure what I would do there? Bore and stroke are about the same right? Just missing a couple cylinders? There's so many other fuel paremeters based off this... Think I would use 5.7L bin and set cylinder to 6, copy over 4.3L spark and fuel tables to start, but with the big change in injector VE gonna need a lot of work and with Vortec Head Spark Table is going to need work, maybe rough in a Vortec head bin spark table to start then you'd be way closer to work on the fuel VE.

I just did something simalar, since 1227747 never came with 7.4L and a 700R4 I took a 5.7L 700R4 bin and copied in all the 7.4L engine paremeters. So basically made a stock GM 7.4L engine and 700R4 tranny bin. Took about an hour but guy said it runs great and just needs some tweaking because of the 7.4L engine mods. He was about ready to give up after paying a mail order chip company $250 and several logs and new chips to get no where...

**PJG1173** · 06-04-2012

bore and stroke on the 4.3 are exactly the same as a 5.7. when using the TBI SA tables on the vortec heads with the 4.3 injectors at stock FP i was globally rich. once I went to a LT1 spark table it started leaning out for me to the point I had to bump up FP to keep up. Then I crossed 80% duty cycle so I switched to 5.7 injectors at stock fuel pressure.

Crash does this have a stock vortec cam or tbi cam? I have a SA table I copied from a 2000 4.3 somewhere on my computer. I'll post it once I find it. that might be a better starting point for you.

here are a couple things I experimented with. first is a screen shot of the 2000 SA table from efilive. second is a spread sheet I used to format it like the SA table in the mask I'm using.

EagleMark, looks like the site does not accept office 2010 document extensions. I had to convert the spreadsheet to office 2007 in order to post it.

**crash8212** · 06-05-2012

EagleMark,
The fuel pressure runs at around 12psi and will drop to around 9 psi under heavy throttle. There is a good ground present so I doubt power is an issue, although the fuel pump may be a little weak as it has 130k on it (didn't replace it...yet).

PJG1173,
The cam is the stock 91 TBI. Everything is stock other than the heads, intake, headers and injectors.

Factory hp rating for the 91 TBI was around 135, 2000 was around 195hp, other than the cam 190-ish should be close to the rating of this engine which is why I originally believed the injectors were too small.

I am still VERY new to the tuning terminology so this is taking me a few minutes to decipher. I thought this might be a simple issue of turning off the EGR and VSS but now it seems I may be in a little over my head for a first time tuning endeavor. I understand about 99% of what all of you are discussing and suggesting but nearly 100% ignorant on how to go about merging bins, editing VE and SA tables for Vortec heads and such.

I have no idea what the BPW READ ME HACK is

I have 3-4 options at this point and I am trying to make the most cost and time effective judgement.
1 - Call up TBICHIPS.com and have a chip burnt with my specs (I think thats a long shot, but the owner seems to think its not, I am entirely skeptical)

2 - Attempt to learn this myself and buy an Ostrich to tinker a bit until I am sure I can do it then a burner to finalize and nag the heck out of the forum members through it all

3 - I learned today that a friend knows one of the GM engineers that helped originally pioneer the FI system for GM and knows EVERYTHING there is to know about them (according to friend) and he lives less than a mile from me and he still enjoys setting up OBD1 and OBD2 FI systems for his own and his friends race cars (8.0 second Camaros). Will try to pick his brain this weekend if he cares to meet me

4 - Carb and HEI (aka giving up, last resort)

**EagleMark** · 06-05-2012

Originally Posted by crash8212

EagleMark,
The fuel pressure runs at around 12psi and will drop to around 9 psi under heavy throttle. There is a good ground present so I doubt power is an issue, although the fuel pump may be a little weak as it has 130k on it (didn't replace it...yet).

PJG1173,
The cam is the stock 91 TBI. Everything is stock other than the heads, intake, headers and injectors.

Factory hp rating for the 91 TBI was around 135, 2000 was around 195hp, other than the cam 190-ish should be close to the rating of this engine which is why I originally believed the injectors were too small.

I am still VERY new to the tuning terminology so this is taking me a few minutes to decipher. I thought this might be a simple issue of turning off the EGR and VSS but now it seems I may be in a little over my head for a first time tuning endeavor. I understand about 99% of what all of you are discussing and suggesting but nearly 100% ignorant on how to go about merging bins, editing VE and SA tables for Vortec heads and such.

I have no idea what the BPW READ ME HACK is

I have 3-4 options at this point and I am trying to make the most cost and time effective judgement.
1 - Call up TBICHIPS.com and have a chip burnt with my specs (I think thats a long shot, but the owner seems to think its not, I am entirely skeptical)

2 - Attempt to learn this myself and buy an Ostrich to tinker a bit until I am sure I can do it then a burner to finalize and nag the heck out of the forum members through it all

3 - I learned today that a friend knows one of the GM engineers that helped originally pioneer the FI system for GM and knows EVERYTHING there is to know about them (according to friend) and he lives less than a mile from me and he still enjoys setting up OBD1 and OBD2 FI systems for his own and his friends race cars (8.0 second Camaros). Will try to pick his brain this weekend if he cares to meet me

4 - Carb and HEI (aka giving up, last resort)

Well fuel pressure can't drop to 9, this may be the low voltage I saw on data log. Check charging system to see it is charging to around 14 volts, if not fix it. Then look at how the power wire is run to fuel pump relay and from relay to pump. Could be worn pump or supply line from pump to TBI also.

Other things can be turned off as needed.

Answers to questions!
1. Is not a good option, as I said above...

He was about ready to give up after paying a mail order chip company $250 and several logs and new chips to get no where...

2. Is an option if you want to learn.

3. I used to work for them. It will cost more then option number 1 if he will even take time to talk to you.

4. Not an option.

Can you burn chips yet?

**crash8212** · 06-05-2012

Originally Posted by EagleMark

Well fuel pressure can't drop to 9, this may be the low voltage I saw on data log. Check charging system to see it is charging to around 14 volts, if not fix it. Then look at how the power wire is run to fuel pump relay and from relay to pump. Could be worn pump or supply line from pump to TBI also.

Other things can be turned off as needed.

Answers to questions!
1. Is not a good option, as I said above...

2. Is an option if you want to learn.

3. I used to work for them. It will cost more then option number 1 if he will even take time to talk to you.

4. Not an option.

Can you burn chips yet?

I will check on the voltage to the fuel pump tomorrow and see if there is a drop or bad ground and also check charging system.

As far as the engineer goes, he is a friend of a friend that just enjoys doing it in his spare time from what I'm told. Not as a side business although I was told a few years ago that he would have built me a wiring harness to connect the 4.3 computer to the Jeep main harness for around $100 (total coincidence that its the same guy). I had already made it myself at that point but would have been more than worth the $100 for a plug in setup. If a high price tag turns out to be the case I'd rather fork over cash to someone on this forum that is still in the manner of creating their way of life rather than a retired engineer that already has everything and doesn't need more money. Ill find out more Thursday

BTW #4 was more of a joke. I will not be defeated, only beaten up repeatedly.

I can not yet burn chips. I have to make the decision on either the Ostrich or the APU1, both are beneficial to me but one seems to cut a little of the work out (at this point, that seems a moot point though)

Thanks again for all of your help.

BTW, if I were to log more data for help analyzing, what is the best scenario and time frame to do it in? I know warmed up and in closed loop but is there a min/max time frame and an acceleration or idle period to go through to set a baseline? Anything helps, I'm learning this, the next step is to learn Tunerpro much better once I have learned the purpose of the info it provides.

**PJG1173** · 06-05-2012

I reccomend the APU1 works real well for me chip reader/writer/emulator all in one package. the 4.3 in my truck is my first tuning experiance too. the learning curve is a little steep but once you get the basics you'll be set and things will fall right into line. sounds like you have one heck of a jeep some pics would be nice! as mentioned these things don't like unsteady voltages or fuel pressure taking care of these should make a big difference. if I'm not mistaken the 91 4.3 came with a 1 wire o2 sensor. you might want to upgrade to a 3 or 4 wire sensor as the headders may mess with the readings if they are long tubes. from the sounds of it you haven't strayed too far from stock. shouldn't be too hard for a first time tuner. IMO you could probably get away with using the 4.3 injectors