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Thread: 350 Vortec wi th 454 TBI running pig rich

  1. #1
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    350 Vortec wi th 454 TBI running pig rich

    As a relative newbie, need some advice. Converted '98 350 Vortec to TBI using 454 throttle body, 4 barrel intake and adapter. Have several injectors from 305, 350 and 454 TBIs. Purchased Cop Car injectors that are NOT marked supposedly 65 pph. Keep running into the same situation wherein the engine runs pig rich at idle. Fuel pressure at present is 14 psi. Just switched to 350 injectors and still runs pig rich. Installed adjustable pressure regulator and have it at lowest pressure setting. Still runs rich.

    Found that Oring sizes and fit are critical in the fuel portion of the TBI. Got the wrong size, wrong fit and it hydraulically LOCKED the engine. Pulled all the spark plugs and rotated with starter. Got a gasoline bath. Tried to dry out plugs and reinstalled. Still misfiring and running pig rich. Went to the auto parts store for new spark plugs. Need to get these installed and try again.

    Advise needed for this situation.

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    I just put 454 injectors (80 lb/hr) over my TBI 383. Had to update the BPW/BPC for the displacement, injector flow, and fuel pressure from 135 to 96. I also deleted the EGR. After a few datalogs and updates to the VE table it is running very well.
    1990 Chevrolet K2500, RCLB, Blueprint 383 TBI (16197427 ECM / 80 lb/hr / 15 psi FP), NV4500, NP241, 3.42

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    Quote Originally Posted by Chewy1576 View Post
    I just put 454 injectors (80 lb/hr) over my TBI 383. Had to update the BPW/BPC for the displacement, injector flow, and fuel pressure from 135 to 96. I also deleted the EGR. After a few datalogs and updates to the VE table it is running very well.
    Did you replace the electric fuel pump with one that could achieve higher pressure? What was the fuel pressure set at? Don't understand fuel pressure 135 to 96. How was the EGR deleted. Did you emulate to update the VE tables? Was a wideband O2 sensor/display hooked up when modifying the VE tables? Please advise. Thanks.

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    Fuel Injected! BLG355's Avatar
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    It sounds like you have too much fuel. Your VE tables will need updated, but you need to get something close for it to work off of. Are you sure you don't have a pinched return line or something? Does it lean out when it warms up and gets into closed loop? Can you post a datalog?

    BLG
    My Build: 95 K1500, 355ci w/ OEM roller setup - zero decked, Eagle steel crank, Scat bushed H-beam rods, Speed Pro 2V flat top pistons - Rotating assembly balanced. Dart 165cc Iron Eagle S/S heads - 72cc chambers - 1.94 / 1.50 valves. Isky roller cam - 204/209 dur @ .050 - .480/.496 lift with Comp Magnum 1.6 rockers, Edelbrock 3704 intake - Bored to 52mm - 454 throttle body, Delco EP381 fuel pump @ 18 psi running through 80# 454 injectors. Hedman Headers into 3" Dynomax exhaust.

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    Quote Originally Posted by BLG355 View Post
    It sounds like you have too much fuel. Your VE tables will need updated, but you need to get something close for it to work off of. Are you sure you don't have a pinched return line or something? Does it lean out when it warms up and gets into closed loop? Can you post a datalog?

    BLG
    Would be pleased to attach a datalog. As a relative newbie, learning how to tune the hard way. Get little bits and pieces. Yet it may all add up in the end. The engine is a 1998 350 Vortec with a 4 barrel manifold on top of which is a 454 throttle body on an adapter. It is on a run-in stand right now. Will check to see if the fuel return line is clear. Using export Vortec 5.7L TBI binary file. Fuel Pressure is at 12-14 psi. Purchased supposed 65 pph injectors off of Ebay. Came unmarked look refurbished. Hooked up Innovate LM-1 Wide Band AFR. Runs 10 AFR at idle. Occasionally, leans out to 17 AFR and almost quits at idle then goes back to rich AFR. Installed used 350 (slightly smaller) injectors, same rich AFR results.

    Thinks maybe it is the MemCal. Will pull the MemCal from the 1995 Chev C1500 pickup, and try, that the Vortec on the engine stand is to be installed in to replace the oil burner in the pickup now.

    Seems as though it is in Limp Home Mode (LHM) all the time??? Please advise. Thanks.

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    Quote Originally Posted by rsicard View Post
    Did you replace the electric fuel pump with one that could achieve higher pressure? What was the fuel pressure set at? Don't understand fuel pressure 135 to 96. How was the EGR deleted. Did you emulate to update the VE tables? Was a wideband O2 sensor/display hooked up when modifying the VE tables? Please advise. Thanks.
    Yes I installed an EP381 fuel pump and 18 psi spring in the regulator to achieve a higher pressure. It was the Base Pulse Width that I changed from 135 to 96. 135 was the value from the factory with 350 cubic inch engine, 56 #/hr injectors, and 13 psi fuel pressure. I'm now at 383 cubic inches, 80 #/hr injectors, and 18 psi fuel pressure. There is a spreadsheet Dave W created in another post that will do this calculation for you. To delete the EGR I sandwiched an aluminum plate between the valve and the intake to seal the port, then increased the EGR enable RPM to its maximum value. Dave W's spreadsheet will also update VE tables if you can input your current table and average BLM values from a datalog. Update and log a few times and it gets very close to running efficiently. I don't have a wideband O2, just a new Bosch replacement sensor.
    1990 Chevrolet K2500, RCLB, Blueprint 383 TBI (16197427 ECM / 80 lb/hr / 15 psi FP), NV4500, NP241, 3.42

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    Quote Originally Posted by Chewy1576 View Post
    Yes I installed an EP381 fuel pump and 18 psi spring in the regulator to achieve a higher pressure. It was the Base Pulse Width that I changed from 135 to 96. 135 was the value from the factory with 350 cubic inch engine, 56 #/hr injectors, and 13 psi fuel pressure. I'm now at 383 cubic inches, 80 #/hr injectors, and 18 psi fuel pressure. There is a spreadsheet Dave W created in another post that will do this calculation for you. To delete the EGR I sandwiched an aluminum plate between the valve and the intake to seal the port, then increased the EGR enable RPM to its maximum value. Dave W's spreadsheet will also update VE tables if you can input your current table and average BLM values from a datalog. Update and log a few times and it gets very close to running efficiently. I don't have a wideband O2, just a new Bosch replacement sensor.
    Thanks much for the reply. You have a 747 ECM, I have a 7427 ECM. Was the base pulse width setting item in the Scalars, Flags or Tables? Guessing the Scalars. Trying to interpret which item should be changed for base pulse width in the long list of TunerPro for 7427 ECM which I have. Understand what Dave W. has done with the spreadsheets. Just trying to lean out the fuel some as a first step.

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    I'm not 100% sure but I think it's call Base Pulse Constant in the 7427 ECM. For me, the Base Pulse Width was one of the first scalar values in the parameter list.
    1990 Chevrolet K2500, RCLB, Blueprint 383 TBI (16197427 ECM / 80 lb/hr / 15 psi FP), NV4500, NP241, 3.42

  9. #9
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    injector flow rate TBI in your xdf.
    dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants

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    Quote Originally Posted by delcowizzid View Post
    injector flow rate TBI in your xdf.
    dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants
    Try to understand what "injector flow rate TBI in your xdf" is supposed to mean. "Altitude spark bias" don't understand. Please advise. Thanks.

  11. #11
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    Quote Originally Posted by delcowizzid View Post
    injector flow rate TBI in your xdf.
    dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants
    The reader has NO idea what the writer is trying to convey. Have no idea what is in the writers brain.

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    Quote Originally Posted by delcowizzid View Post
    injector flow rate TBI in your xdf.
    dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants
    I am certain that you are trying to help, yet don't understand the meaning of what you have said. Need to spell out what is in your thoughts.

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    rsicard,

    With all due respect, stop posting and start searching and reading. You have started so many post, yet not followed through with anyones advice. Go here http://www.gearhead-efi.com/Fuel-Inj...g-Error-Codes! and read all the sticky links. When your'e done, read them all again. Same here http://www.gearhead-efi.com/Fuel-Inj...-quot-FAQ-quot

    There are hour after hour of great reading information in those links.
    89 K1500 Scottsdale 5.7L 5spd 3:42

    Build specs: 97 4 bolt main block 350ci, Eagle rotating assembly with flat tops and 4 valve reliefs, Dart 165cc/67cc Iron Eagle heads, Manely SS valves and springs 110lbs seat @1.7, GM Ram Jet cam 196/206 @.50 .431/.451, stock intake and throttle body, heads and intake gasket matched, Delco EP377 fuel pump @ 22 psi, 427 PCM.

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    Quote Originally Posted by brian617 View Post
    rsicard,

    With all due respect, stop posting and start searching and reading. You have started so many post, yet not followed through with anyones advice. Go here http://www.gearhead-efi.com/Fuel-Inj...g-Error-Codes! and read all the sticky links. When your'e done, read them all again. Same here http://www.gearhead-efi.com/Fuel-Inj...-quot-FAQ-quot



    There are hour after hour of great reading information in those links.
    Brian617: Understand what you are saying. Have read at least 1/2 of what you have provided links for. Have spent many an hour reading through the materials. Still have open questions. Understand if the guys on here are getting tired of seeing my name. But after not achieving an objective, there is much more to do. I will go off and read the other link you posted and gather a compendium of what was posted. Maybe it will provide more insight. So the responses have come in little bits and pieces that do not form a bigger complete picture in the mind. Maybe forming a compendium of the other link will do the job. Every person uses their own terminology. Lots of TLAs. Again, the reader does not know what is in the writers mind unless the writer spells it all out the picture in his mind. Find this to be a very common problem leading to misunderstandings and taking the wrong path forward. See this every day.

    Getting really tired and frustrated of seemly getting NOWHERE. Only on about the 7th or 8th run on the engine stand. Got a whole collection of injectors and regulator springs. No positive way to measure their performance. Don't have automated test equipment to test the ECMs for quality of performance. Worked in engineering on the B2 bomber 750 shaft Horse Power Aux Power Unit (APU) Electronics Control Unit (ECU). Characterized the ECU and formed Lotus 123 spread sheet of input and outputs with limits and tested the Line Replaceable Units (LRUs) in 45 seconds with embedded 8088 microprocessor on Std buss rack. Worked like gang busters. Lots of experience in Aerospace Electronics.

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    Fuel Injected! DOCBAWRENCHTURNER's Avatar
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    rsicard- I have been in the same boat with the engine running pig rich. the BPW is in the scalars. I believe that there is a calculator/excel file somewhere to help with this. I ended up telling the PCM that my injectors are larger than what it has in it due to my increased fuel pressure. Also the number your changing is a pcm based number, it will be somewhere around 10 and probably a decimal. You also need to make sure that you IAC is set to where it needs to be (there is a write up about this). I believe Mark said he aimed for ~20 counts.

    edit... I understand your frustration that after 7-8 tries you haven't been able to see any progress, keep in mind that most people here have tried 10-20 times a day. There is a method to this madness, but the learning curve is steep. I have a 96 Vortec engine in a 95 pickup running TBI, similar issues, but we all have to work one step at a time.
    Last edited by DOCBAWRENCHTURNER; 03-24-2015 at 02:26 PM.

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