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1991 5.7L Bored TBI Upgrade Write-up (warning LOTS of pics!)
- Thread starter pma4x4
- Start date
pma4x4
AKA Yankeeroad
Sorry guys. was one a burb hiatus for a couple years. I am back and am working on getting all my thread pics back up and running. stay tuned.
pma4x4
AKA Yankeeroad
Pics are all back up!
Since I have done this mode also I want to add a few little tidbits.
For guys who dont add a TB spacer- I ran into an issue with the driver side fuel line when adding the fuel pressure gauge. The line no matter how I tweaked it would not line up enough to connect. The hard line was hitting the distributor since it was pushed rearward due to the gauge adapter. The only way to correct this is to A. make a new line B. delete the hard line. For the time being I have opted to go back to the factory fuel pressure setup. Sooner than later I will finish the adjustable fuel pressure mod. Since the rebuild the vehicle stubbles all over itself so thinking I have a fuel pressure issue.
If anyone has not had this issue let me know what you did. I would love not to modify anything.
Upgrading to the adjustable fuel pressure using a stock TBI intake- You will find that there is no passthrough in the body of the intake for the adjuster screw. Don't be afraid to drill a hole. It only needs to be big enough for a Dremel Burr Bit. I highly suggest doing this, it makes for a nice clean look, eliminates any alignment issues, and reduces the chance of destroying your TB by using a larger drill bit.
TB Injectors- On the side of each of your injectors there is a small filter screen. Whether you are replacing, reusing in a rebuild, or inspecting your injectors make sure these are present. The filters are part of the rebuild kit. While rebuilding mine I noticed the screen was blown out in one. The injector it came out of has drips in the fuel spray pattern. I am assuming the blown out screen is the cause and will need to replace the injector.
For guys who dont add a TB spacer- I ran into an issue with the driver side fuel line when adding the fuel pressure gauge. The line no matter how I tweaked it would not line up enough to connect. The hard line was hitting the distributor since it was pushed rearward due to the gauge adapter. The only way to correct this is to A. make a new line B. delete the hard line. For the time being I have opted to go back to the factory fuel pressure setup. Sooner than later I will finish the adjustable fuel pressure mod. Since the rebuild the vehicle stubbles all over itself so thinking I have a fuel pressure issue.
If anyone has not had this issue let me know what you did. I would love not to modify anything.
Upgrading to the adjustable fuel pressure using a stock TBI intake- You will find that there is no passthrough in the body of the intake for the adjuster screw. Don't be afraid to drill a hole. It only needs to be big enough for a Dremel Burr Bit. I highly suggest doing this, it makes for a nice clean look, eliminates any alignment issues, and reduces the chance of destroying your TB by using a larger drill bit.
TB Injectors- On the side of each of your injectors there is a small filter screen. Whether you are replacing, reusing in a rebuild, or inspecting your injectors make sure these are present. The filters are part of the rebuild kit. While rebuilding mine I noticed the screen was blown out in one. The injector it came out of has drips in the fuel spray pattern. I am assuming the blown out screen is the cause and will need to replace the injector.
It is with profound sadness that Vic Morse, owner and operator of RV Morse Machine, passed away on August 7, 2021. The business will be closed and is no longer taking orders. In Memoriam forthcoming.
Thank you for your prayers and wishes. http://www.rvmorsemachine.com/
Thank you for your prayers and wishes. http://www.rvmorsemachine.com/
That's sad to hear. What better way to remeber Vic by posting up some of his handy work. Pictured is a TBI that Vic modified, which is currently running my 1991 V3500 Crew Cab. He bored it out 1/8", milled down all the air horns, re-bushed the throttle shaft, rebuilt the injectors, and match flowed them.
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saw this on facepalm, don't know anything about the company, but might be something I should get.
Custom programmed High performance chip for 1987-91 K5 TBI Trucks (replaces factory chip) , Must state which engine you have ! Much better acceleration and driveability over stock. The Stage 2 street tune is for stock vehicles and offers a dyno proven gain on stock vehicles. MUCH better towing power and the Stage 2 street tunes we offer are great for just plain stock vehicles and offer Dyno proven HP at the WHEEL
Price is $76 shipped. Custom tuning also available
https://m.facebook.com/F-body-ECM-Programming-1449489875293854
https://fbodyecmprogramming.square.site/
Custom programmed High performance chip for 1987-91 K5 TBI Trucks (replaces factory chip) , Must state which engine you have ! Much better acceleration and driveability over stock. The Stage 2 street tune is for stock vehicles and offers a dyno proven gain on stock vehicles. MUCH better towing power and the Stage 2 street tunes we offer are great for just plain stock vehicles and offer Dyno proven HP at the WHEEL
Price is $76 shipped. Custom tuning also available
https://m.facebook.com/F-body-ECM-Programming-1449489875293854
https://fbodyecmprogramming.square.site/
The small block TBI does not make much power to begin with, and it is not capable of making very much more. The promises of more power seem over the top for an engine that is not capable of making much power to begin with.
