Weird Tuning Issue

[Jsup]

Now, first thing is I am hell bent on making this work with the stock ECU.

That being said here's the werid condition.

Basis: 1990, Small block 427, 42lb injectors (bosch), 240/246 roller cam 1.6 RRs. Long tube headers.

I have a wideband sensor hooked up, as well as FP guage, and OBDI Analyzer, I forget the brand. The O2 sensor is in the collector of the headers, One O2 sensor on the drivers side is a 4 wire heated aftermarket sensor. The wideband is on the passenger side in the same location.

Here's the deal, around 2400 RPMs the ECU tries to pull fuel out because the O2 sensor is telling it to. However, the Wide Band on the other side is reading lean.

The first thing I'm going to do is switch the sides, put the O2 sensor hooked to the driver's side into the passenger side collector and put the wideband on the driver's side to see what happens.

Any thoughts of what would be causing this?

 

[mrvette]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

 

[Jsup]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

Fuel pressure is 55 lbs. It is a MAP, Speed Density.

the injector wires fit only one way, and because it's batch fire why would it matter?

 

[mrvette]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

Fuel pressure is 55 lbs. It is a MAP, Speed Density.

the injector wires fit only one way, and because it's batch fire why would it matter?

Wondered if you had a weird computer output problem...failure of some sort...

55 lbe sounds a tad high to me....42 lbs injectors I supposed to do 350+ on only 24 lbs and so with those 42's maybe back off a bit down to 42 psi....I am told injectors don't like too high a pressure.....unless of course you know more about what your injector supplier rates them at.....I do assume they are all identical....hate to get you into cutting your harness, so wonder if you put a fuel gauge on it, run it a minit, then watch the pressure drop, it should be 15 minits before it goes to maybe 1/2 value....you maybe have a leaky injector.....

:suicide:

 

[Jsup]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

Fuel pressure is 55 lbs. It is a MAP, Speed Density.

the injector wires fit only one way, and because it's batch fire why would it matter?

Wondered if you had a weird computer output problem...failure of some sort...

55 lbe sounds a tad high to me....42 lbs injectors I supposed to do 350+ on only 24 lbs and so with those 42's maybe back off a bit down to 42 psi....I am told injectors don't like too high a pressure.....unless of course you know more about what your injector supplier rates them at.....I do assume they are all identical....hate to get you into cutting your harness, so wonder if you put a fuel gauge on it, run it a minit, then watch the pressure drop, it should be 15 minits before it goes to maybe 1/2 value....you maybe have a leaky injector.....

:suicide:

I checked with Jon at FIC, I got the injectors from him. He says no problem with 55 lbs. I have a new, high volume fuel pump that will support the pressure.

The injectors were tested and flow matched before they left the factory. It's only at 2400RPMs or so, at 3000 it's rich, well, 13.X anyway.

Everything is new and seems to be working fine. The adjustable FPR came with the intake and is fine too. Car runs great everywhere but 1500-2400 RPMs.

 

[mrvette]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

Fuel pressure is 55 lbs. It is a MAP, Speed Density.

the injector wires fit only one way, and because it's batch fire why would it matter?

Wondered if you had a weird computer output problem...failure of some sort...

55 lbe sounds a tad high to me....42 lbs injectors I supposed to do 350+ on only 24 lbs and so with those 42's maybe back off a bit down to 42 psi....I am told injectors don't like too high a pressure.....unless of course you know more about what your injector supplier rates them at.....I do assume they are all identical....hate to get you into cutting your harness, so wonder if you put a fuel gauge on it, run it a minit, then watch the pressure drop, it should be 15 minits before it goes to maybe 1/2 value....you maybe have a leaky injector.....

:suicide:

I checked with Jon at FIC, I got the injectors from him. He says no problem with 55 lbs. I have a new, high volume fuel pump that will support the pressure.

The injectors were tested and flow matched before they left the factory. It's only at 2400RPMs or so, at 3000 it's rich, well, 13.X anyway.

Everything is new and seems to be working fine. The adjustable FPR came with the intake and is fine too. Car runs great everywhere but 1500-2400 RPMs.

HUMM....take the air induction off the throttle body just for test....

after that if no change, methinks you into the programming, and obviously the cam profile interaction with what program you are running....

if it's running under load at say 2600 rpm's will it eventually correct itself??

have you tried that yet?? there is always some learning/correction built into all them chips/computers almost sounds like that type of range....

:flash:

 

[Jsup]

I get real tired of my OBD1 anal y sir have to reset the vehicle inputs every time....PIA....must be a dozen key strokes...

I presume this is a batch fire sysem like mine.....do you run a MAF, or is it speed density like mine???

you have the batches set in each side?? like mine....

if so you maybe want to switch the injector wires around if it's easy to get at....

listen to the injectors on each side with a stethescope, they sound all the same??? what is your fuel pressure??

Fuel pressure is 55 lbs. It is a MAP, Speed Density.

the injector wires fit only one way, and because it's batch fire why would it matter?

Wondered if you had a weird computer output problem...failure of some sort...

55 lbe sounds a tad high to me....42 lbs injectors I supposed to do 350+ on only 24 lbs and so with those 42's maybe back off a bit down to 42 psi....I am told injectors don't like too high a pressure.....unless of course you know more about what your injector supplier rates them at.....I do assume they are all identical....hate to get you into cutting your harness, so wonder if you put a fuel gauge on it, run it a minit, then watch the pressure drop, it should be 15 minits before it goes to maybe 1/2 value....you maybe have a leaky injector.....

:suicide:

I checked with Jon at FIC, I got the injectors from him. He says no problem with 55 lbs. I have a new, high volume fuel pump that will support the pressure.

The injectors were tested and flow matched before they left the factory. It's only at 2400RPMs or so, at 3000 it's rich, well, 13.X anyway.

Everything is new and seems to be working fine. The adjustable FPR came with the intake and is fine too. Car runs great everywhere but 1500-2400 RPMs.

HUMM....take the air induction off the throttle body just for test....

after that if no change, methinks you into the programming, and obviously the cam profile interaction with what program you are running....

if it's running under load at say 2600 rpm's will it eventually correct itself??

have you tried that yet?? there is always some learning/correction built into all them chips/computers almost sounds like that type of range....

:flash:

Yes, under load at 2600-2800 or so it smooths out and doesn't run lean. Just in that one spot around 2400.

 

[mrvette]

I have no other suggestion than programming in the fuel map....sorry to say....

did you try redoing the air induction, by dropping the piping and air cleaner down to a naked tbody??? don't have to drive is very far to eliminate that slim change....but it's worth a shot, as opposed to going nutz and finding that.....

I can't help you on the programming.....I understand some later GM computers are sequential and have a much broader learning capability, similar to what the Mega Squirt system I tried 2 years ago was supposed to have.....it never worked out for me though....

:crutches::flash:

 

[Jsup]

I have no other suggestion than programming in the fuel map....sorry to say....

did you try redoing the air induction, by dropping the piping and air cleaner down to a naked tbody??? don't have to drive is very far to eliminate that slim change....but it's worth a shot, as opposed to going nutz and finding that.....

I can't help you on the programming.....I understand some later GM computers are sequential and have a much broader learning capability, similar to what the Mega Squirt system I tried 2 years ago was supposed to have.....it never worked out for me though....

:crutches::flash:

What would stripping the induction do? What would that tell me?

 

[Bullshark]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

 

[mrvette]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

I tend to agree, and know it's a shot in the dark....but the price in time and $ is right, just a thought.....

me being cheeeep.....and all, .....:lol:

 

[Jsup]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

Greg has an excellent reputation and has been tuning cars for years. Most of the cars he has tuned have been blown cars of the 350/383 variety. I think with my cam he's never seen this kind of build....

Carroll Supercharging/Blowerworks has been doing these cars for years, and I can't find anything bad about him. PLUS I can't find anyone local who has the equipment to tune this thing. He's not a tailight tuner, just the opposite, he's been working with me through the hiccups. My trans blew so we couldn't tune, and to his defense I had those POS Accel ignition parts which shit the bed. The car wouldn't run right no matter what so I had to replace cap, rotor, wires to resolve that before we can even get the tune right. The baseline was all wrong because the car would never fire right.

Getting those problems resolved put us almost perfect on the tune. The issue is that if I block the bottom BLM 112 I have no problems. If I drop it to 90, it will go to 90. Essentially we're starting from scratch. I don't blame him for that.

 

[Bullshark]

Peace.....just pulling your chain.:devil:

 

[mrvette]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

Greg has an excellent reputation and has been tuning cars for years. Most of the cars he has tuned have been blown cars of the 350/383 variety. I think with my cam he's never seen this kind of build....

Carroll Supercharging/Blowerworks has been doing these cars for years, and I can't find anything bad about him. PLUS I can't find anyone local who has the equipment to tune this thing. He's not a tailight tuner, just the opposite, he's been working with me through the hiccups. My trans blew so we couldn't tune, and to his defense I had those POS Accel ignition parts which shit the bed. The car wouldn't run right no matter what so I had to replace cap, rotor, wires to resolve that before we can even get the tune right. The baseline was all wrong because the car would never fire right.

Getting those problems resolved put us almost perfect on the tune. The issue is that if I block the bottom BLM 112 I have no problems. If I drop it to 90, it will go to 90. Essentially we're starting from scratch. I don't blame him for that.

I think I maybe have a 1/2 assed idea of what/why/IS a BLM......but can someone explain that clearly??? I think it a area of the fuel map that is drawn like a mountain range in diagrams with colors all over it....but I dunno even if that's right, really....

so me the whole thing is a analogue problem and simpler solved that a ways than digitally....but that's ME.....

:waxer::flash:

 

[Jsup]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

Greg has an excellent reputation and has been tuning cars for years. Most of the cars he has tuned have been blown cars of the 350/383 variety. I think with my cam he's never seen this kind of build....

Carroll Supercharging/Blowerworks has been doing these cars for years, and I can't find anything bad about him. PLUS I can't find anyone local who has the equipment to tune this thing. He's not a tailight tuner, just the opposite, he's been working with me through the hiccups. My trans blew so we couldn't tune, and to his defense I had those POS Accel ignition parts which shit the bed. The car wouldn't run right no matter what so I had to replace cap, rotor, wires to resolve that before we can even get the tune right. The baseline was all wrong because the car would never fire right.

Getting those problems resolved put us almost perfect on the tune. The issue is that if I block the bottom BLM 112 I have no problems. If I drop it to 90, it will go to 90. Essentially we're starting from scratch. I don't blame him for that.

I think I maybe have a 1/2 assed idea of what/why/IS a BLM......but can someone explain that clearly??? I think it a area of the fuel map that is drawn like a mountain range in diagrams with colors all over it....but I dunno even if that's right, really....

so me the whole thing is a analogue problem and simpler solved that a ways than digitally....but that's ME.....

:waxer::flash:

I'm sorry, I said BLM I meant Integrator. The BLOCK LEARN MODE (now I'm not a tuning expert) is where the computer looks under specific conditions pre determined by the factory. Limp home for example is BLM 4. Hill acceleration would be another, flat acceleration would be another. MY UNDERSTANDING AS LIMITED AS IT IS is that the ECU looks at all the sensors, vacuum, air temp, RPMs, MPH, etc and makes a decision which block to throw it into.

The INTEGRATOR is a mechanism where it learns. The high and the low can be set. The stock low is about 90. I had to move that up to 110 to keep it from going too low and pulling out too much fuel.

Its target is 128 so it has to add or subtract fuel to get to the magic 128. 90 is pulling out. WHY? because the O2 is reading rich, so it's trying to go lean to get to where it needs to be. Problem is according to the wideband, it's not rich, so it's creating a lean condition.

 

[Bullshark]

Jsup, one of the primary reasons GM incorporated the BLM and Integrator learn functions was to help the narrow band O2 in doing it's job in closed loop. You are correct about the two learn modes. The Integrator and Block Learn (I and BL) and Block Learn Memory (BLM) cell. The I and BL feature is normal with a value of around 128. If this value is higher than 128, it indicates that the ECM is adding fuel to the base fuel calculation because the system is running lean, a value lower than 128 indicates that the ECM is taking out fuel because the system is running rich. The integrator is a short term corrective action while the BLM is along term correction. The BLM value will change if the integrator has seen a condition which lasts for a longer period of time. The ECM learns how much adjustment is required in each cell, retains it in memory, and applies these adjustments when the engine operates in that cell or RPM - Load Range. These features of the OEM ECM allows the system to adjust itself AUTOMATICALLY to your engine and assure peak performance for stock and other than stock engines as long as the engine modifications result in a VE that are within the limits of the learning calibration range. I suspect that your engine's base calibration is off. I am also inclined to have more faith in the UEGO wideband O2 sensor readings. It would be interesting to check the wideband O2 sensor accuracy. What kind do you have. If it is a LC-1 it has a built in calibration function that I would trust. Aftermarket EFI systems that utilize the wide range and resolution of the UGEO typically don't depend on Learn functions.
I guess what I recommend is utilize a wideband to get all your base cells accurate and go from there.

Bullshark

BTW, I am thinking the base BLM factory modifier values may need calibrating to your engines new setup. Thinking out loud here, but maybe the Integrator function cannot tweak the BLM values enough over the longer term to get them within proper operating range??????

 

[mrvette]

I have no other suggestion than programming in the fuel map....sorry to say....

Bingo:thumbs:

Time for that expert tuner Jsup......hope his warranty isn't a "tail light warranty". (i.e. expires when he looses sight of your tail lights) :stirpot:

Bullshark

Greg has an excellent reputation and has been tuning cars for years. Most of the cars he has tuned have been blown cars of the 350/383 variety. I think with my cam he's never seen this kind of build....

Carroll Supercharging/Blowerworks has been doing these cars for years, and I can't find anything bad about him. PLUS I can't find anyone local who has the equipment to tune this thing. He's not a tailight tuner, just the opposite, he's been working with me through the hiccups. My trans blew so we couldn't tune, and to his defense I had those POS Accel ignition parts which shit the bed. The car wouldn't run right no matter what so I had to replace cap, rotor, wires to resolve that before we can even get the tune right. The baseline was all wrong because the car would never fire right.

Getting those problems resolved put us almost perfect on the tune. The issue is that if I block the bottom BLM 112 I have no problems. If I drop it to 90, it will go to 90. Essentially we're starting from scratch. I don't blame him for that.

I think I maybe have a 1/2 assed idea of what/why/IS a BLM......but can someone explain that clearly??? I think it a area of the fuel map that is drawn like a mountain range in diagrams with colors all over it....but I dunno even if that's right, really....

so me the whole thing is a analogue problem and simpler solved that a ways than digitally....but that's ME.....

:waxer::flash:

I'm sorry, I said BLM I meant Integrator. The BLOCK LEARN MODE (now I'm not a tuning expert) is where the computer looks under specific conditions pre determined by the factory. Limp home for example is BLM 4. Hill acceleration would be another, flat acceleration would be another. MY UNDERSTANDING AS LIMITED AS IT IS is that the ECU looks at all the sensors, vacuum, air temp, RPMs, MPH, etc and makes a decision which block to throw it into.

The INTEGRATOR is a mechanism where it learns. The high and the low can be set. The stock low is about 90. I had to move that up to 110 to keep it from going too low and pulling out too much fuel.

Its target is 128 so it has to add or subtract fuel to get to the magic 128. 90 is pulling out. WHY? because the O2 is reading rich, so it's trying to go lean to get to where it needs to be. Problem is according to the wideband, it's not rich, so it's creating a lean condition.

Something that drove Spiro and me crazy in the lab for over a week was a instrumentation error, grounding shit and so maybe something like that in your wiring....I thought I made a improvment with rewiring some ground ref point in the O2 sensor of my 1227730 GM computer speed density install with aftermarket Cal pack.....the wire was 'mistakenly' grounded in a line with one of the injector power grounds.....it maybe made a improvement, but my raggedy assed idle persisted...maybe check your grounding for wire routing, every damn ground get it's own wire to engine directly...like I wound up doing....

just for shits and grins so to save money or embarr ass ment....:rain:

 

[Jsup]

I think what I am going to do is buy an Ostrich, there's a Bluetooth version that is currently available.

With that, I am going to also pick up Tuner Cat, or Tuner Pro RT to tune, I will leave the Ostrich hooked up and run the car off it.

Finally I'm going to pick up Datamaster or similar program to run logs.

I'm going to learn this stuff myself. And continue to work with Greg.

Anyone have any preference on software? Tuner Cat? Tuner Pro? Data Master? Scan Pro? what do you think?

 

[mrvette]

I think what I am going to do is buy an Ostrich, there's a Bluetooth version that is currently available.

With that, I am going to also pick up Tuner Cat, or Tuner Pro RT to tune, I will leave the Ostrich hooked up and run the car off it.

Finally I'm going to pick up Datamaster or similar program to run logs.

I'm going to learn this stuff myself. And continue to work with Greg.

Anyone have any preference on software? Tuner Cat? Tuner Pro? Data Master? Scan Pro? what do you think?

Just to be sure you see this....IMO you got a fair chance to have WATER in your gasoline....same shit that happened to me a month+ ago...

drain the tank and dry it out totally, clean the lines and stick some good gas in there.....it's that I wound up doing.....

NEVER had a car so prone to getting water in the tank....total mystery as to WHY....

:cussing:

 

[Bullshark]

I think what I am going to do is buy an Ostrich, there's a Bluetooth version that is currently available.

With that, I am going to also pick up Tuner Cat, or Tuner Pro RT to tune, I will leave the Ostrich hooked up and run the car off it.

Finally I'm going to pick up Datamaster or similar program to run logs.

I'm going to learn this stuff myself. And continue to work with Greg.

Anyone have any preference on software? Tuner Cat? Tuner Pro? Data Master? Scan Pro? what do you think?

Jsup, Since you are committed to the GM stock computer, I think you are on the right track with the Ostrich. That should give you alot of the capability you are going to need. I used Tuner Pro, and Scanner Pro on my GM MEFI ECU on Ramjet before going to the Gen 7. I thought it was a good choice and the price is right.

Bullshark