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Thread: IS TBI back?

  1. #1
    Fuel Injected!
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    Cool IS TBI back?

    After 20 years in retirement from the auto industry I recently started taking select clients to help pay rent on my lab.
    In the 1980s I had a small fuel injection and carb shop with a partner who was the carb guy.
    I must have repaired hundreds of DFI and 468 Cadillacs Olds and Crossfire Corvettes.
    After the carb shop I had a Small Corvette shop for 5 years and was recruited by DCS Corvette action center.
    Raced 28 weeks of the year as a Busch Grand National Nascar crew chief.
    Then I retired and walked away from the whole industry.
    I was contacted by a guy who had 3 of the 1984 corvettes and no 1226026 ECMs available.
    There might be a few still alive but it does not matter much anyway.
    The only way the old tune is going to feel right is to run REC90 fuel since all the old O2 sensors are targeted at 14.7 narrowband.
    You see they are selling 10% ethanol as pump gas and it is stoichiometric at 14.2.
    On the old engines with TBI lean power is 14.6 and that is dangerous lean for Gasohol stuffs going to break.
    Another old trick the 160 ThermoStat means most likely your oil is going to be black with alcohol and water.
    180 is needed to evaporate alcohol completely and purge the water vapor from the oil.
    So I built a Harness Adapter and installed a Microsquirt first hard street pull it jumped the timing chain so I will be back tuning it next month.

    I actually pulled my notes from the attic and built a flow bench for the crossfire again.
    Nothing like rebushing 35 year old Throttle Bodies.

    Another friend is HotRodding a 1967 Mustang.
    His number one desire is to have a reliable ride with HotRod looks and sound.
    I actually recommended he switch to a TBI to cope with the drivability issues he has had with 4 different new carbs.

    So is it time for TBI to come back?

    Also I am trying to decide about my own truck.
    I got a very nice 95 suburban with 278K on the clock interior is great with later model seats, dual zone ac and all the LS niceness.
    The motor not so much bad fuel pump, EGR valve, broken exhaust manifold bolts and manifolds.
    The truck was set up full hill billy 2 inch raise with rubber in the front springs and spacer in the back, Reese hitch and electric brakes, Over sized tire on 15" rims, running boards, busted grill with brush guards, 6 inch side belts monkey snot glued on, basically embarrassing.
    So far I have dropped it 6 inches all around, drilled the heads and installed Tri-Y headers and Zoomies at the rear door.
    Stripped the plastic chrome and built a grill for the front, lost the rear bumper, made some foam rear valance panels, set 285 / 40 R 17 on Black 17x10 rims.
    Pulled the 8 track and cassette decks placed a Pioneer DVD head unit.
    Painted the top hammer coat silver (Mandatory in Florida), the lower valance, hood and boot black hammer coat.

    So I have two choices on my engine for this build.
    I have a nasty LT-4 that tachs out to 8500 and peaks at 600HP at 6500, 595Ft# at 5200.
    I need to re-ring and re-seal, Replace the crank trigger and DIS about $3500.

    The other is to put the old stock LT-4 roller cam in the truck block, timing gear set, Port and cut the heads, MOD the injector, Rebuild Dizzy, victor junior, Microsquirt Module, Oil pump, 2 piece timing cover, One piece pan gasket, Electric water Pump Good for about 375 Max at RW. $1000

    One thing that is making me back away from the hotter engine is that I already have rear end wind up causing a really impressive squat at take off from the lights but scaring the crap out of me with the lowered springs in the rear. With the Zoomies I no longer have room for slappers or a caltrak. So I need to build a torque arm for a 10Bolt chevy. 400HP real easy 600HP the arm will break when I punch it.

    Also I might give one of those cheap power stroke diesel turbos a try later.

    Opinions welcome.

  2. #2
    Super Moderator dave w's Avatar
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    I don't know if TBI is coming back or not. TBI is an affordable option.

    TunerPro RT http://www.tunerpro.net/ is an excellent TBI tuning software, a suggested $39 donation.

    The Ostrich 2.0 available from Moates.net http://www.moates.net/ostrich-20-the....html?cPath=64 eliminates the need for chip burning equipment and when interfaced with TunerPro RT provides TBI Real Time tuning while driving!

    TBI is affordably tuned with a Wide Band O2 sensor http://www.gearhead-efi.com/Fuel-Inj...g)-Spreadsheet, see attached screen shots below.

    dave w
    Attached Images Attached Images
    Last edited by dave w; 12-29-2017 at 05:24 PM.

  3. #3
    Fuel Injected! uncabob's Avatar
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    WOW!
    Welcome to the forum. Good info.
    My build is a ratrod 49 Jimmie PU with a 84 corvette Xfire against aTH400.
    20k original miles on the engine. Using original TBI.
    Could not find an original harness or ECM so went with the 1227747.
    Not on the road yet but still working on the running gear and body.
    Will a WBO2 help with the gasahol stoich problem?
    Bob
    Don't force it, get a bigger hammer!

  4. #4
    Super Moderator dave w's Avatar
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    Quote Originally Posted by uncabob View Post
    Will a WBO2 help with the gasahol stoich problem?
    It will help with understanding what the Air Fuel Ratio is in the exhaust. Is the engine running lean or running rich? Knowing what the Air Fuel Ratio is in the exhaust is very helpful for tuning the Oxygen Sensor voltage offsets and fuel table parameters for ethanol blended fuels. I often think of a WBO2 as just another tool in the toolbox, it simply measures the Air Fuel Ratio in the exhaust, nothing else. It's similar to a digital caliber, it's up to the skill of the user to know to do with the measurements from a digital caliper. The same is true with a WBO2, it's up to the skill of the tuner to know what to about the Air Fuel Ratios measured in the exhaust.

    Once the WBO2 Air Fuel Ratio is included into a data log, corrections for an engine running Rich / Lean is less challenging ( corrections to fuel tables are actually measureable).

    Using a laptop to fix a fuel table parameter is similar to changing jets in a carburetor, expect no gasoline smell in the shop.

    dave w

  5. #5
    Fuel Injected!
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    Quote Originally Posted by uncabob View Post
    Could not find an original harness or ECM so went with the 1227747.
    Not on the road yet but still working on the running gear and body.
    Will a WBO2 help with the gasahol stoich problem?
    Bob
    Hi bob
    Yes a few years ago people started substituting the 1227747 all three of the vettes had them on the floor when I got them.
    There was a harness adapter to plug and play but most just re pinned the connectors.
    My guys mechanics did not all three have electrical issues now.
    I liked the GM ECU66 that was in the LT-1 and Cats Tuner for the tunes.
    I will probably have to get a prom burner for the memcal ECMs used to have a TECH 1000 terminal, now for the older ECMs I only have an OTC with the cartridges.
    I have the pin outs for the 1227747 and the 1226026.
    I think I will post those with some other stuff I accumulated.

    From what I understand about the ECM O2 input it is using the high or low signal to develop a block learn count that adjusts the fuel so I am not sure if the WBO2 on the old ECMs will function correctly.
    At a birds eye view it will indicate if the system is running rich or lean so you can make adjustments manually I guess.
    I am thinking about this for my own truck project.
    Ideally I think a signal conditioner using a OP amp like a 741 or a 358 for duals would allow you to adjust the stoic preset and produce the narrowband signal to feed to the ECM.
    Also I am thinking about making or hacking a flex fuel sensor to provide a basis for stoic condition.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  6. #6
    Fuel Injected!
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    Thanks Dave W
    Is there a unix / linux software that will work with the Ostrich?
    The Windows stuff is a no go for me.

    Also I see a lot about the WBO2 on the nets but I am failing to understand.
    Are you guys using the WBO2 on old ECMs in closed loop or as a tuning aid with an external meter/gauge ?
    After reading a bit on the forums I see that you are pulling the WBO2 off an unused EGR pintle position ADC and logging it.
    Are you using the data in the block learn algorithm ?

    From GM ECM repair school back in the early 1980s I understood that the O2 inputs on the ECMS are Hardware preset low and high thresholds set around the narrowband 14.7 response. I thought that the O2 signal is sampled at a software preset rate and after a software preset number of samples Hi or LOW it increases or decreases the block learn for that map/rpm cell.
    Is the WBO2 functioning in these systems ?
    Last edited by daveosx; 12-29-2017 at 11:00 PM. Reason: Added understanding
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  7. #7
    Super Moderator dave w's Avatar
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    Quote Originally Posted by daveosx View Post
    Thanks Dave W
    Is there a unix / linux software that will work with the Ostrich?
    The Windows stuff is a no go for me.

    Also I see a lot about the WBO2 on the nets but I am failing to understand.
    Are you guys using the WBO2 on old ECMs in closed loop or as a tuning aid with an external meter/gauge ?

    From GM ECM repair school back in the early 1980s I understood that the O2 inputs on the ECMS are Hardware preset low and high thresholds set around the narrowband 14.7 response. I thought that the O2 signal is sampled at a software preset rate and after a software preset number of samples Hi or LOW it increases or decreases the block learn for that map/rpm cell.
    Is the WBO2 functioning in these systems ?
    Good question on using the Ostrich 2.0 with Linux. I have not used Linux. It appears Linux using "Wine" is an option for using TunerPro (http://forum.tunerpro.net/viewtopic....e06f5c2346242e). Wine information (https://www.linux.com/LEARN/how-inst...ications-linux).

    WBO2 is a data tool only. WBO2 it is a tuning aid with an external meter/gauge . WBO2 data has been "hacked / reverse engineered" to stream real time into a data log. The WBO2 data in the data log Does Not affect or control BLM, the factory O2 sensor is still needed to control BLM fueling. Having the WBO2 data stream real time in the data logs, allows for frame by frame or sample by sample comparison of the Air Fuel Ratio for any given MAP / RPM cell.

    The best use for WBO2 tuning is for Acceleration Enrichment aka AE (Carburetor Pump Shot) and Power Enrichment aka PE (4 barrel Carburetor Secondary opening up). The TBI computer will lock the BLM's at 128 when fueling for AE & PE. Imagine how awesome it would be to tune a carburetor for 12.5 Air Fuel Ratio, when the 4 barrel secondary opens up. Imagine using a laptop instead of changing jets to adjust for 12.5 Air Fuel Ratio! Imagine how awesome it would be to tune a carburetor to have the 4 barrel secondary open up at 50% or 60% or 70% or ??% Throttle Position with a laptop! Imagine how awesome it would be to know what the carburetor Air Fuel Ration is at WOT. I don't imagine these things, I data log with WBO2 to SEE Exactly what those Air Fuel Ratios are.

    The second generation TBI computer (#16197427) is my TBI computer of choice. R.I.P 122774 http://www.gearhead-efi.com/Fuel-Inj...out-Directions!

    It's fair for me to mention, I'm an EFI Tuner and Custom EFI Harness builder (aka Old School EFi LLC).

    dave w

  8. #8
    Fuel Injected!
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    Thanks Dave W

    I am sitting here having a senior moment over thinking the whole thing.

    The O2 sensor is just reading the O2 in the exhaust stream as long as it is up to temperature the stoichiometry should not effect the O2 reading.
    The mechanical pressure regulator of the TBI is probably all thats really needed to adjust to prevent the 10% ethanol lean conditions.

    If the pressure to flow rate is in the linear portion of the injector curve (14.7 - 14.2)/14.7 = .034 or 3.4% increase in fuel pressure would compensate.
    So figure 5-7% increase in fuel pressure to cover enrichment this would allow block learns to return to more normal gasoline levels.

    I love the carburetor references
    I have always been a fuelie guy.
    Even the old rochester mechanicals.

    Like everyone else the jump to computers has dulled my old school memory of the physics of fast.

    I was thinking of a way to enable older ECM vehicles to run the E85 for the power boost.
    Started a little searching and found a great post on a DIY FLEX fuel sensor setup .
    https://forums.nasioc.com/forums/sho....php?t=2810122

    So I am thinking ...
    Maybe a second set of two TPI style injectors squirting in the same bores as the TBI.
    I could trigger the second set using the ground side of the existing injectors as inputs to the arduino and a couple of Mosfets coming out.
    Use the Alcohol content reading for the PWM of the AnalogWrite(output,ALK)
    That would give me a fuel adder that is proportional to Alcohol content.
    Now for the timing...
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  9. #9
    Fuel Injected!
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    My brain just kicked in again.
    Back in the early 90s we had something of a tax dodge government inspired fad called BI-FUEL.
    They where 500Bar CNG tanks feeding a TBI spacer with two Proportional valves.
    If I remember correct the proportioning valves used two injection signals from the ECM.
    The way the system worked was that the driver could select CNG, Gasoline or both.
    On CNG the vehicles really had no power but in "hybrid mode" the truck would switch between fuels on load.

    I am thinking that my E85 power adder idea could be possible from the ECM without the arduino.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  10. #10
    Super Moderator dave w's Avatar
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    Without overthinking things, it's true ... with enough time and money a mountain of recycled aluminum cans could be turned into a supersonic jet fighter.

    On the money side of things, I think leveraging a factory flex fuel system is a modestly affordable option. My plan for flex fuel would not use TBI, I would opt for TPI instead. I would update the TPI engine to OBD2, using parts from EFI Connection https://www.eficonnection.com/home/c...x-product-line

    Ok, with the 24x system installed on the TPI engine using a factory LSx computer, it's a downhill slide to configure a factory LSx flex fuel system to a TPI engine.

    The 24x system uses the coil on plug ignition system, so programmable timing to a maximum of 60 degrees of dwell is available.

    Why TPI not TBI, most LSx computers are running engines with 8 injectors.

    The 24x system allows using OBD2 tuning software from EFI Live or HP Tuners.

    dave w

  11. #11
    Fuel Injected!
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    Yep mountain of money
    I have another project I am trying to save for a Nelson LSX for my WS6.

    On the cheap a lot of TBI has hit the u-pull salvage yards.

    I really never liked OBDII always felt it was way too much nanny state.

    Actually was thinking of making a throttle body spacer with extra injectors run off an arduino for quick power add and retain the unaltered ECM and memcal.

    I am going to look at what the cheapest FLEX sensor is today at the parts store.

    Enrichment curve should be easy enough to map based on % alcohol in fuel.
    Last edited by daveosx; 12-31-2017 at 09:15 PM.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  12. #12
    Super Moderator dave w's Avatar
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    I was posting thoughts and ideas, based on proven products and software. Perhaps the options I mentioned could stir new ideas and information exchanges.

    I see many challenges with a 160 baud TBI ECM, with a 4K chip.

    I see affordable solutions using the OBD1 based EBL Flash System: http://www.dynamicefi.com/

    Perhaps a combination of affordable salvage yard TBI Hardware combined with an aftermarket enhanced code / ECM hardware.

    dave w

  13. #13
    Fuel Injected!
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    The only TBI resurgence I'm seeing is the cheap aftermarket TBI systems like the Holley Sniper.

    As for your truck, put the slapper bars above the spring.

  14. #14
    Fuel Injected!
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    The slappers are no go for me
    No room between the coach bottom and the spring its a suburban.
    I have Zoomies that exit in the little gap between the rear door and the tire well and the truck is dropped 6 inches so the springs are only 3 inches from the floor of the truck above the spring 1.5 inches to the Zoomies frame mount.
    I did come up with a torque tube design I think will work.

    I have motor mounts on a 500SEC to do tomorrow.

    Then I'll FAB a torque tube style rear end locator.
    Last edited by daveosx; 01-01-2018 at 04:08 AM.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  15. #15
    Fuel Injected!
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    Yes I know the ECM is real slow but I was thinking of just picking up the ground signal off the TBI injectors.
    Rather than try and communicate with the ECM.
    More a electromechanical than a computer style power adder.
    Years ago I used a GM 3Bar map sensor to control boost enrichment on a turbo BMW with Ljetronic just added fuel with injectors in parallel with the stock ones.
    When boost came up the second set of injectors turned on used a VCO and an AND gate to control proportional fuel.
    Just AND the injector pulse with the VCO output for secondary injector control.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

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