ok, that sounds easy enough, just watch data in WinALDL. I am pretty sure ssyorks tbi is modded for adjustable fpr.
CK5
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New cam
- Thread starter ssyork
- Start date
MNorby don't you have an AutoProm? If so get it ready to emulate, get the .ads or .adx file so you can read data instead of WinALDL and Viola! 
dave w
1/2 ton status
I was referring to general tuning.
For the break in, if I were to see a lean condition I would add to the BPW a couple numbers. Adding to the BPW a few numbers has about the same effect on fuel flow as adding a some fuel pressure. Adding fuel pressure is more of a course adjustment, and changing the BPW is still a course adjustment but on a smaller scale. Changing a few VE cells is also an option, but I like to use an actual calculated value (math stuff) when changing a VE cell.
dave w
I've read people say WinALDL give more log data than Tunerpro gives so I have gotten used to running it i guess. We're not worried about tuning right now, just making sure we can safely break the new cam in.
My fuel pressure reg is adjustable, but already set to max.
Here is another sorta related questions but mostly for my own knowledge. What the max number you ever want to see the BPW set at? I've read if its too long it can overheat the injector???
This is something you can set by doing the math. I'm just a newb here so this is a cut and paste answer. One thing to add is that on a TBI engine the injectors go static (100% open) at 15 or times two so 7.5 secs. They are also prone to be eratic just before this stage so if you need more fuel you'll need more fuel pressure.
The BPW constant is the relationship of the volume of a single cylinder to the injector size. For TBI, it is as follows:
TBI
; Val = 1461.5 * (VOL/RATE)
; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec
I
The BPW constant is the relationship of the volume of a single cylinder to the injector size. For TBI, it is as follows:
TBI
; Val = 1461.5 * (VOL/RATE)
; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec
I
dave w
1/2 ton status
Correct, to much BPW will overheat the injector.
I tend to think the max number is realistically 170. By accident, I ended up using 5.7 liter injectors on an almost stock 7.4 liter. When the BPW was adjusted to what seemed an extreme 170 and some of the fuel VE tables were close to 90, I figured out the injectors were the wrong size.
dave w
Broke the cam in last night without any major problems. It did not want to idle very well with my stock tune. Seemed to run alright at the higher rpms. I have put the big block tbi on tonight and we are going to start with a stock big block tune and go from there. I was checking things out though and it seems the brown wire that you unhook to time it is not connected to anything. It has a butt connector on it but is only crimped on the one endo the brown wire and has never been crimped on the other. Is this going to be a problem?
Never mind. I found it. Don't know what the other disconnect is though. Purple on one side and then brown on the wire not connected to anything..
Get it all wired in yet?
Just heading to bed now. I got the new computer in with stock big block tune, minus a few things. Gt the aldl connector wired in andmounted under dash, chk engine light wired and found the right disconnect for the setting the timing. Then I handful of other little things.
y5mgisi
1 ton status
So by the looks of this, 7747 and 8747 are swapable? Just some of the tables on the chip are different?
Stick with whats right! KISS! 
If it was a 7747 truck to start just stay there! 7747, 8747 and 8746 are usually swapable. But one, maybe 2 don't have knock sensor. The big problem is definition files are differant. Last I looked one of the 8787 or 8786 never got one made...
Disclaimer: I have done all these in conversions but this was all from memory.
Do your research and make sure the Defs are available .adx and .xdf
If it was a 7747 truck to start just stay there! 7747, 8747 and 8746 are usually swapable. But one, maybe 2 don't have knock sensor. The big problem is definition files are differant. Last I looked one of the 8787 or 8786 never got one made...
Disclaimer: I have done all these in conversions but this was all from memory.
Do your research and make sure the Defs are available .adx and .xdf
y5mgisi
1 ton status
I know mine has a knock sensor. It also has the est module.
dave w
1/2 ton status
The 8747 is swappable with a 7747 and vise / versa with a custom chip. From my very limited research (for just one vehicle) the 7747 and 8747 have the same wiring (for just the one vehicle I researched)
What I also noticed is the 8747 was used with a TH400 and the 7747 was used for the TH700R4 (for just the one vehicle I researched)
The TH400 uses a Kickdown relay that is wired to the ECM.TunerPro does not support the 8747 very much! For the beginner chip programmer, the 8747 can be challenging! If there is an option to swap a computer, hands down I'd retire both the 8747 and 7747 and install a 16197427 PCM. The headaches are all equal, IMHO, when swapping a 7747 / 8747 / 16197427. The 7747 / 8747 share the old 160 baud rate!
dave w
Still may be both on a Big Block! That's probably why/what I am remembering from them and they were simple swaps.
7747 or up. Don't try to reinvent the wheel.
8746 was not the Big Block truck I was thinking. That was the 1228747
The 1228746 is a very good ECM and will plug into 7747 harness. It's about identical except it has a MAT sensor as well. Had one in my 1993 9C1 TBI Police car (NotaCop) I think they were in camaros to from like 1990 to 1993.
This is getting confusing? Seems like theres two projects going on now?
I have a 4F.XDF but could not find a 4F.ADX Since the ones I did were simple swaps I probably just used my Scan Tool to check data and the .XDF to change what needed. But l didin't get into tuning because the ECM was what came with stock engine.
7747 or up. Don't try to reinvent the wheel.
8746 was not the Big Block truck I was thinking. That was the 1228747
The 1228746 is a very good ECM and will plug into 7747 harness. It's about identical except it has a MAT sensor as well. Had one in my 1993 9C1 TBI Police car (NotaCop) I think they were in camaros to from like 1990 to 1993.
This is getting confusing? Seems like theres two projects going on now?
I have a 4F.XDF but could not find a 4F.ADX Since the ones I did were simple swaps I probably just used my Scan Tool to check data and the .XDF to change what needed. But l didin't get into tuning because the ECM was what came with stock engine.
I can not verify that. Listen to these other guys! All of my very limited knowledge has been learned on this truck, and definitely have way more to learn. Here is what I started with and what I have now. Started with a 1990 3/4 ton with a 5.7 and a 4 speed. I put an nv4500 in and everything worked great. Then I added Vortec heads off a 96 a few years later. I daily drove it with only a little stumble when I floored it and an occasional check engine light that never stayed on. All on a stock chip in an 8747 computer. Then I changed to a fuel pump out of a 96 and did the tbi mods and it ran great still on the 8747 w/stock, chip. Now I added a new cam, the bottom side of a bb tbi unit, the fuel pod off of my old small block tbi with the pressure maxed out, 7747 comp, and a stock bb tbi chip from a manuel tranny with the egr and knock sensor turned off,since I have neither of these. I haven't hooked a computer up yet, but will on the first day of bb on Hells. It runs great now, no stumbles or bobbles anywhere. Had a mechanic friend drive it also and he said it feels and sounds good too. Still want to hook up the computer and see what it looks like and also keep learning.
dave w
1/2 ton status
I posted a screen shot of the 8747 and 7747 Timing and VE tables. The 8747 has only one VE table with more cells than the 7747, the 7747 has two VE tables. The 8747 has higher RPM's in the both VE and Timing tables.
dave w
y5mgisi
1 ton status
Thats pretty crazy that that mix match of parts turns out to run well! Good stuff! Dave, You just got me wondering about something. Using winaldl, i have mine set to the 7747 setting. Does 7747 and 8747 use the same setting? Or am i just out of whack on my computers?
