Block Learn readings of 154-160.............because my injectors are undersized?
12-11-2001, 11:59 AM
#1
Member
Thread Starter
Block Learn readings of 154-160.............because my injectors are undersized?
Just trying to keep my learning going.......have a 406 TPI motor in my Blazer........and with my new Auto Xray scanner (dangerous I know) I check all sorts of stuff just to learn what is normal, etc. My BLM's are in the 154-160 range, indicating, according to my book, that the injectors are forced to add fuel.........and that a reading of 120 should be 'normal'. Now I have 24lb/hr injectors, am I taking the leap here of assuming this high BLM reading means I have undersized injectors? Is this really an issue?
Integrator is about 128 most always.......
TIA
------------------
'79K5 Blazer with 406TPI
Integrator is about 128 most always.......
TIA
------------------
'79K5 Blazer with 406TPI
12-11-2001, 07:45 PM
#2
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
Which TPI? SD or MAF? I need to know more about your system before I can tell you how to fix it.
Currently, you are on the verge of triggering an SES "O2 Lean" code while in part-throttle. I have no idea of how lean you are in WOT. You could be at the verge of a "melt down" if you are getting BLMs of that level.
If you were running 19# injectors you may have "overcorrected" conversely if you had 22# injectors, you didn't go big enough. You MIGHT fix the "part-throttle" by "mechanical fixes" (bigger injectors) but I think you need a custom eprom to ensure you are getting the proper amount of fuel in part-throttle and WOT.
BTW, 128/128 is "perfect" fo BOTH BLM and INT. That is what we strive for at ALL rpm/load values of the powerband.
Currently, you are on the verge of triggering an SES "O2 Lean" code while in part-throttle. I have no idea of how lean you are in WOT. You could be at the verge of a "melt down" if you are getting BLMs of that level.
If you were running 19# injectors you may have "overcorrected" conversely if you had 22# injectors, you didn't go big enough. You MIGHT fix the "part-throttle" by "mechanical fixes" (bigger injectors) but I think you need a custom eprom to ensure you are getting the proper amount of fuel in part-throttle and WOT.
BTW, 128/128 is "perfect" fo BOTH BLM and INT. That is what we strive for at ALL rpm/load values of the powerband.
12-11-2001, 07:47 PM
#3
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
Oh, also, in WOT you'll notice the BLM/INT change to 128/128. This does NOT mean you are now running "perfect". It means you are in "Power Enrichment" Mode and that you are relying on your eprom's fuel tables - no O2 sensor correction.
Hope this helps.
Hope this helps.
12-11-2001, 08:13 PM
#4
Member
Thread Starter
<font face="Verdana, Arial" size="2">Originally posted by Glenn91L98GTA:
Which TPI? SD or MAF? I need to know more about your system before I can tell you how to fix it.
Currently, you are on the verge of triggering an SES "O2 Lean" code while in part-throttle. I have no idea of how lean you are in WOT. You could be at the verge of a "melt down" if you are getting BLMs of that level.
If you were running 19# injectors you may have "overcorrected" conversely if you had 22# injectors, you didn't go big enough. You MIGHT fix the "part-throttle" by "mechanical fixes" (bigger injectors) but I think you need a custom eprom to ensure you are getting the proper amount of fuel in part-throttle and WOT.
BTW, 128/128 is "perfect" fo BOTH BLM and INT. That is what we strive for at ALL rpm/load values of the powerband.</font>
Which TPI? SD or MAF? I need to know more about your system before I can tell you how to fix it.
Currently, you are on the verge of triggering an SES "O2 Lean" code while in part-throttle. I have no idea of how lean you are in WOT. You could be at the verge of a "melt down" if you are getting BLMs of that level.
If you were running 19# injectors you may have "overcorrected" conversely if you had 22# injectors, you didn't go big enough. You MIGHT fix the "part-throttle" by "mechanical fixes" (bigger injectors) but I think you need a custom eprom to ensure you are getting the proper amount of fuel in part-throttle and WOT.
BTW, 128/128 is "perfect" fo BOTH BLM and INT. That is what we strive for at ALL rpm/load values of the powerband.</font>
By the way, if a person upped the lb/hr of their injectors (say from 24-28) is a rework of the custom chip required?
Might my 'fix' for this high BLM count be an AFPR, which I ordered from TPIS last week? Not sure what my stock fuel pressure is but also ordered a 0-100 lb gauge to check it. I will 'baseline' it as soon as the gauge shows up before I put in the AFPR.
------------------
'79K5 Blazer with 406TPI
12-12-2001, 08:34 AM
#6
Supreme Member
Join Date: Sep 1999
Location: Manassas VA
Posts: 3,197
Likes: 0
Received 6 Likes
on
5 Posts
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
Well, you're engine is cureenlty trying to add 20% fuel in part throttle conditions to the tables. That means your chip isn't even vaguely close to correct for your combo during those conditions.
You could put an AFPR on it, but thats a mechanical cludge and will never be as good as fixing the problem, the chip. Also, there is no way you could even add 20% fuel with an AFPR, you'd need to run close to 65psi. Most AFPRs don't get that high, and even if they did you would fry your fuel pump running it at that presure constantly.
In other words you are at a crossroads. You can continue to drive t and use whatever kludges you like to get it closer to 'right' (but still way off), or you can get into the chip and fix the root of the problem, that your VE tables and your injector constant are both off. The latter fix is the only one i can recomend, since it is a true fix. To treat the PROM as a constant and try to kludge around it may work in a half-assed way, but will never be truly close to correct. Even if you get your BLMS into a more reasonable area during closed loop, your WOT stuff will still prolly be way off. Fix your WOT stuff and your closed loop will prolly be way off. You'll be chasing your tail, pulling your hair out, and hopefully not have a melted down engine by the time you realize that inside the PROM is where you need to be. Even if getting into the PROM seems like a daunting task to you, keep in mind you don't have to get it anywhere near perfect. You're off by 20% or more right now, thats easy to get in the correct ballpark by changine one number (your injector constant), then you can tweak other stuff from there depending on what you see.
------------------
Ed Maher - Moderator @ The TPI & Carb Boards
92 Z28 Convertible - Quasar blue / Tan top
305 TPI A4 2.73 - 14.7 @ 93.6
Stock except ported plenum and dual cats
-=ICON Motorsports=-
- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die
You could put an AFPR on it, but thats a mechanical cludge and will never be as good as fixing the problem, the chip. Also, there is no way you could even add 20% fuel with an AFPR, you'd need to run close to 65psi. Most AFPRs don't get that high, and even if they did you would fry your fuel pump running it at that presure constantly.
In other words you are at a crossroads. You can continue to drive t and use whatever kludges you like to get it closer to 'right' (but still way off), or you can get into the chip and fix the root of the problem, that your VE tables and your injector constant are both off. The latter fix is the only one i can recomend, since it is a true fix. To treat the PROM as a constant and try to kludge around it may work in a half-assed way, but will never be truly close to correct. Even if you get your BLMS into a more reasonable area during closed loop, your WOT stuff will still prolly be way off. Fix your WOT stuff and your closed loop will prolly be way off. You'll be chasing your tail, pulling your hair out, and hopefully not have a melted down engine by the time you realize that inside the PROM is where you need to be. Even if getting into the PROM seems like a daunting task to you, keep in mind you don't have to get it anywhere near perfect. You're off by 20% or more right now, thats easy to get in the correct ballpark by changine one number (your injector constant), then you can tweak other stuff from there depending on what you see.
------------------
Ed Maher - Moderator @ The TPI & Carb Boards
92 Z28 Convertible - Quasar blue / Tan top
305 TPI A4 2.73 - 14.7 @ 93.6
Stock except ported plenum and dual cats
-=ICON Motorsports=-
- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die
12-12-2001, 09:32 AM
#7
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
I agree with Ed, that eprom is WAY OFF and needs to be redone.
If your engine is a "mild" 400 with TPI, 24# injectors should be more than adequate to 5,000 rpm for the power characteristics of your 400 TPI. In fact, I have found the 22# injectors with the stock SD L98 bin tends to be overly rich by 15-20%. With the fuel pressure around 45-46 psi I am confident that a TPI on a mild 400 could work with 22# injectors, with the RIGHT changes to the eprom.
I would need to know more about your engine and mods to make a definitive call on what minimum injector size you need. There is a down-size to too large of injectors. The ECM can only shorten the pulse width so much, so getting a proper idle may become a problem. This is the challenge guys have with a heavily modded engine running large injectors with the stock ECM.
My hunch is the person the burnt you that eprom (if it was for your 400) screwed up. Either they overstated the Injector Size in the engine (causing it to run leaner than it should) OR they failed to increase the Cylinder Displacement (again causing you to run lean).
I also agree with Ed that the change needed by increasing the fuel pressure is quite dramatic. Also, increasing fuel pressure has its greatest effect at "high load" (climing hills and WOT) and least effect at "low load" (idle, light throttle and deceleration).
What is 8 28# injectors going to cost you? The Pocket Programmer only costs $149.00 and the TunerCat Editing software $69.00 (if you order the $8D TDF with the TunerCat software, you may save the $20 for that, they did when I got mine).
Since you have SD, you DON'T need a UV Eraser, just a couple of Flash Proms ($5.00 each). And you don't need a scan tool as you got one already.
So the total cost to get into eprom burning is under $250.00 AND you can tune your engine perfectly and better than ANY custom eprom you can buy, except one where the eprom writer personally did "hands-on tuning" for you with a dyno and WB O2 sensor. And also did a fair amount of "part-throttle" driving with you on the street. But the cost of that is prohibitive and that STILL may not get you a "perfect" eprom.
If you got the equipment, you could even mail the BIN to some fellow members on the DIY Prom Board that might be willing to help you get through your inital "teething".
While I don't "burn eproms", I don't mind taking a quick look at the BIN from a fellow "eprom burner" to see what the initial problem is and help make a recommendation (or the change if it is a "quick fix"). But they must submit the BIN to me and have the equipment.
It is too bad it is not the summer, we could meet at a "Cascade Crew Gathering" and I could take a quick look at that eprom to see what the problem is with the excessive lean condition. Not enough "Cascade Crew members" are interested (or believe) in eprom burning. Too many are quick to recommend a "mechanical fix" instead of fixing the real problem, the eprom. This is because most don't understand what the eprom REALLY does.
[This message has been edited by Glenn91L98GTA (edited December 12, 2001).]
If your engine is a "mild" 400 with TPI, 24# injectors should be more than adequate to 5,000 rpm for the power characteristics of your 400 TPI. In fact, I have found the 22# injectors with the stock SD L98 bin tends to be overly rich by 15-20%. With the fuel pressure around 45-46 psi I am confident that a TPI on a mild 400 could work with 22# injectors, with the RIGHT changes to the eprom.
I would need to know more about your engine and mods to make a definitive call on what minimum injector size you need. There is a down-size to too large of injectors. The ECM can only shorten the pulse width so much, so getting a proper idle may become a problem. This is the challenge guys have with a heavily modded engine running large injectors with the stock ECM.
My hunch is the person the burnt you that eprom (if it was for your 400) screwed up. Either they overstated the Injector Size in the engine (causing it to run leaner than it should) OR they failed to increase the Cylinder Displacement (again causing you to run lean).
I also agree with Ed that the change needed by increasing the fuel pressure is quite dramatic. Also, increasing fuel pressure has its greatest effect at "high load" (climing hills and WOT) and least effect at "low load" (idle, light throttle and deceleration).
What is 8 28# injectors going to cost you? The Pocket Programmer only costs $149.00 and the TunerCat Editing software $69.00 (if you order the $8D TDF with the TunerCat software, you may save the $20 for that, they did when I got mine).
Since you have SD, you DON'T need a UV Eraser, just a couple of Flash Proms ($5.00 each). And you don't need a scan tool as you got one already.
So the total cost to get into eprom burning is under $250.00 AND you can tune your engine perfectly and better than ANY custom eprom you can buy, except one where the eprom writer personally did "hands-on tuning" for you with a dyno and WB O2 sensor. And also did a fair amount of "part-throttle" driving with you on the street. But the cost of that is prohibitive and that STILL may not get you a "perfect" eprom.
If you got the equipment, you could even mail the BIN to some fellow members on the DIY Prom Board that might be willing to help you get through your inital "teething".
While I don't "burn eproms", I don't mind taking a quick look at the BIN from a fellow "eprom burner" to see what the initial problem is and help make a recommendation (or the change if it is a "quick fix"). But they must submit the BIN to me and have the equipment.
It is too bad it is not the summer, we could meet at a "Cascade Crew Gathering" and I could take a quick look at that eprom to see what the problem is with the excessive lean condition. Not enough "Cascade Crew members" are interested (or believe) in eprom burning. Too many are quick to recommend a "mechanical fix" instead of fixing the real problem, the eprom. This is because most don't understand what the eprom REALLY does.
[This message has been edited by Glenn91L98GTA (edited December 12, 2001).]
Trending Topics
12-12-2001, 10:10 AM
#8
Member
Thread Starter
A MAJOR thanks to both you, Ed, and Glenn, for the incredibly informative response. Wow, are you guys good.
The eprom is one that my builder/guru (as I somewhat believe he is) gets from a local guy he has been working with doing the burning for years. What I think is the problem with this situation is the builder is somewhat disorganized in his shop and the chips are all scattered around in a box, with really not the correct labeling. So there may be a 305 chip in there with a 454 chip and not be clearly marked. I have seen it happen with him.
I may seriously consider that eprom burning software/hardware. That is truly the way I want to go in the future........I love doing things myself and do 90% of my all my own work on this truck (if you have seen my website you know what has been done - hint - www.blazzinor.rockcrawler.com ), but for the short term I will talk to my builder, explain the BLM readings, and I expect he will agree a new chip is in order.
Will let you know the outcome.........and again, a heartfelt thanks. Having resources like you guys on this board is incredible.
------------------
'79K5 Blazer with 406TPI
The eprom is one that my builder/guru (as I somewhat believe he is) gets from a local guy he has been working with doing the burning for years. What I think is the problem with this situation is the builder is somewhat disorganized in his shop and the chips are all scattered around in a box, with really not the correct labeling. So there may be a 305 chip in there with a 454 chip and not be clearly marked. I have seen it happen with him.
I may seriously consider that eprom burning software/hardware. That is truly the way I want to go in the future........I love doing things myself and do 90% of my all my own work on this truck (if you have seen my website you know what has been done - hint - www.blazzinor.rockcrawler.com ), but for the short term I will talk to my builder, explain the BLM readings, and I expect he will agree a new chip is in order.
Will let you know the outcome.........and again, a heartfelt thanks. Having resources like you guys on this board is incredible.
------------------
'79K5 Blazer with 406TPI
12-12-2001, 02:35 PM
#9
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
Your welcome. I'm always willing to help people that wish to learn how to burn their own eproms - not just get a "plug 'n play" solution (it generally doesn't work out that well).
If you are comfortable with "tuning" motors (the principles are the same between a carb/reg. dist. and EFI, you just have more things you can control) and a general knowledge of computers, then you will fit right in with us eprom burning guys.
To get MAX performance from an eprom, you need to do a lot of testing, especially with the spark advance. I have some "tricks" I do with the spark advance and knock sensor which can yield a noticeable improvement in performance. I am more than willing to share this information privately to those that are burning eproms, as they are well aware of the risks.
I just don't like posting "that" information publicly as there is a definite risk where you could detonate your motor if you don't know what your are doing or ignore the "danger signs". I don't want some irrate father sueing me becaue his 16 year old kid followed my "advice" and blew up his engine. But for those that are willing to accept the risk and be very careful at the first sign of "ping", you can get a definite performance increase if you take yourself to the "ragged edge".
Maybe next summer, when the Cascade Crew have another gathering, we can meet each other and talk about those things over a beer.
I won't criticize the person that is buring eproms for you, but I will say, I would be damn scared of someone who can make those type of mistakes (305 bin for a 454). Sounds like he did the same thing to you.
You get the equipment and I'll gladly help you.
If you are comfortable with "tuning" motors (the principles are the same between a carb/reg. dist. and EFI, you just have more things you can control) and a general knowledge of computers, then you will fit right in with us eprom burning guys.
To get MAX performance from an eprom, you need to do a lot of testing, especially with the spark advance. I have some "tricks" I do with the spark advance and knock sensor which can yield a noticeable improvement in performance. I am more than willing to share this information privately to those that are burning eproms, as they are well aware of the risks.
I just don't like posting "that" information publicly as there is a definite risk where you could detonate your motor if you don't know what your are doing or ignore the "danger signs". I don't want some irrate father sueing me becaue his 16 year old kid followed my "advice" and blew up his engine. But for those that are willing to accept the risk and be very careful at the first sign of "ping", you can get a definite performance increase if you take yourself to the "ragged edge".
Maybe next summer, when the Cascade Crew have another gathering, we can meet each other and talk about those things over a beer.
I won't criticize the person that is buring eproms for you, but I will say, I would be damn scared of someone who can make those type of mistakes (305 bin for a 454). Sounds like he did the same thing to you.
You get the equipment and I'll gladly help you.
12-12-2001, 04:45 PM
#10
Member
Thread Starter
<font face="Verdana, Arial" size="2">Originally posted by Glenn91L98GTA:
Your welcome. I'm always willing to help people that wish to learn how to burn their own eproms - not just get a "plug 'n play" solution (it generally doesn't work out that well).
If you are comfortable with "tuning" motors (the principles are the same between a carb/reg. dist. and EFI, you just have more things you can control) and a general knowledge of computers, then you will fit right in with us eprom burning guys.
To get MAX performance from an eprom, you need to do a lot of testing, especially with the spark advance. I have some "tricks" I do with the spark advance and knock sensor which can yield a noticeable improvement in performance. I am more than willing to share this information privately to those that are burning eproms, as they are well aware of the risks.
I just don't like posting "that" information publicly as there is a definite risk where you could detonate your motor if you don't know what your are doing or ignore the "danger signs". I don't want some irrate father sueing me becaue his 16 year old kid followed my "advice" and blew up his engine. But for those that are willing to accept the risk and be very careful at the first sign of "ping", you can get a definite performance increase if you take yourself to the "ragged edge".
Maybe next summer, when the Cascade Crew have another gathering, we can meet each other and talk about those things over a beer.
I won't criticize the person that is buring eproms for you, but I will say, I would be damn scared of someone who can make those type of mistakes (305 bin for a 454). Sounds like he did the same thing to you.
You get the equipment and I'll gladly help you.</font>
Your welcome. I'm always willing to help people that wish to learn how to burn their own eproms - not just get a "plug 'n play" solution (it generally doesn't work out that well).
If you are comfortable with "tuning" motors (the principles are the same between a carb/reg. dist. and EFI, you just have more things you can control) and a general knowledge of computers, then you will fit right in with us eprom burning guys.
To get MAX performance from an eprom, you need to do a lot of testing, especially with the spark advance. I have some "tricks" I do with the spark advance and knock sensor which can yield a noticeable improvement in performance. I am more than willing to share this information privately to those that are burning eproms, as they are well aware of the risks.
I just don't like posting "that" information publicly as there is a definite risk where you could detonate your motor if you don't know what your are doing or ignore the "danger signs". I don't want some irrate father sueing me becaue his 16 year old kid followed my "advice" and blew up his engine. But for those that are willing to accept the risk and be very careful at the first sign of "ping", you can get a definite performance increase if you take yourself to the "ragged edge".
Maybe next summer, when the Cascade Crew have another gathering, we can meet each other and talk about those things over a beer.
I won't criticize the person that is buring eproms for you, but I will say, I would be damn scared of someone who can make those type of mistakes (305 bin for a 454). Sounds like he did the same thing to you.
You get the equipment and I'll gladly help you.</font>
I'll let ya know not if, but when, I get into the hardware/software stuff. Any particular place to pick up that stuff online that you can recommend?
Where do you guys usually do the Cascade Crew hookup?
I'll be in touch by email..........thanks.
------------------
'79K5 Blazer with 406TPI
12-12-2001, 06:35 PM
#11
TGO Supporter
Join Date: Jul 1999
Location: The Bone Yard
Posts: 10,907
Likes: 0
Received 3 Likes
on
3 Posts
Car: Death Mobile
Engine: 666 c.i.
All of the Prom Burning equipment is available online. In fact, I don't think you can much of it at an electronics store. I attempted to find some of the equipment and I couldn't find anyone in British Columbia that was able to get all of it. The one or two places that I was able to contact that had Prom Burners wanted an outrageous price. So I followed the links in Tim's (Traxion) Prom Burning Introduction on the top of every web page on the DIY Prom Board.
There is actually a "poll" being conducted of what equipment everyone is using that you can scope out on the DIY Prom Board.
40 years old eh? I'm 46 myself. Many of us "older guys" tend not to go to those "gatherings" as we tend to feel out of place. Just feedback I have gotten from a few of the other "older guys" I chat with in the Northwest area.
I guess if enough of "old guys" go, then I'd go to. I have not actually attended any of the "gatherings" because I feel too old and out-of-place. I know a few more "oldsters" that feel as I do, but maybe we should attend this summer.
There is actually a "poll" being conducted of what equipment everyone is using that you can scope out on the DIY Prom Board.
40 years old eh? I'm 46 myself. Many of us "older guys" tend not to go to those "gatherings" as we tend to feel out of place. Just feedback I have gotten from a few of the other "older guys" I chat with in the Northwest area.
I guess if enough of "old guys" go, then I'd go to. I have not actually attended any of the "gatherings" because I feel too old and out-of-place. I know a few more "oldsters" that feel as I do, but maybe we should attend this summer.
12-12-2001, 07:57 PM
#12
Guest
Posts: n/a
I actually picked up a burner locally, but I live in the 'greater LA' area in Cali so I am probably fortunate in finding stuff locally.
Edit: Actually I picked up everything locally, havent had to order a single thing for burning stuff.
Prom burning is not difficult to do. If you are concerned about getting into it email me and I'll send you a rough copy of a file I am working on, should ease the pain
[This message has been edited by madmax (edited December 12, 2001).]
Edit: Actually I picked up everything locally, havent had to order a single thing for burning stuff.
Prom burning is not difficult to do. If you are concerned about getting into it email me and I'll send you a rough copy of a file I am working on, should ease the pain
[This message has been edited by madmax (edited December 12, 2001).]
Thread
Thread Starter
Forum
Replies
Last Post
9192camaro
Engine/Drivetrain/Suspension Parts for Sale
16
02-03-2019 12:21 AM
