Ultimate TBI Mods: Adjustable Fuel Pressure Regulator 

I did the adjustable regulator/spacer on my sons Camaro. We knew the 305 was coming out of the car, but we kept tweaking on it, and made several passes down the quarter mile to see what we gained. By far, the biggest gain we achieved, to the tune of knocking 4 tenths of his ET, was installing a 3 inch open element air cleaner! (Get the flat base, not the drop base. It will clear the hood)... Now I had some keyboard genius argue that the open element would be worse, (blah blah blah) by letting hot air in the throttle body. ANY air is better than no air, and ET slips don't lie!

This video is soo professionally done. THANK YOU! Good sound, good light and focus. The commentary is stellar in concise delivery..

@ 3rd Gen Guy, I've been doing a lot of research on ways to upgrade and or modify a TBI for more fuel pressure/volume and more CFM's for a 1988 GMC Sierra SLE 4X4 auto trans with basically a stock 5.7L 350cid with flat top 9:1 compression Wheeler pistons, upgraded camshaft to a Comp Cam CL12-256-4, new lifters and springs, Holley Headers long tube 1-5/8 tubes to 3 inch collectors with CO2 sensor bung, 2-1/2 exhaust piping and dual Flowtech Raptor mufflers, cold air intake, 180 degree thermostat, swirl spacer between intake manifold and TBI, dual electric radiator/condenser cooling fans, replaced the pickup stator in distributor while I had it out, I ported my heads exhaust and matched intake to manifold, I did the grind and polish on TBI, thicker injector pod spacer, 14-18 psi regulator spring in TBI, but my present TBI stock fuel pump is barely putting out 11 psi fuel pump pressure, but I'd read an another platform that any type of fuel injected gas engine that's making over 230 horsepower needs to have a fuel pump upgrade, and they recommended the ACDelco in tank electric fuel pump, pn# 25163473, Summit Racing pn# ADO-EP381 $141.99, don't forget to replace the strainer, this fuel pump produces at least 60psi, therefore, you'll have plenty of fuel pressure for whatever type of fuel injection you have, the regulator will control the fuel pressure. I'd also read for the TBI units, you can regulate your fuel pressure to as much as 14 psi, but don't go any higher. Most stock TBI fuel pumps average about 10-12 psi, and one psi makes a big difference in fuel injection and high performance engines. Lastly, I'm gonna research to see if a larger/higher volume fuel injectors and MAP sensor upgrades might be needed for my engine build, along with, I'm gonna see about a specific computer chip for my setup with tbichips.com. Thanks for the video for the add on fuel regulator, I may very well do this on my TBI, especially for the upgraded 60 psi fuel pump.

This will be great for my 93’ Buick Road Master project 🔧

If I’m seeing what I’m seeing This was redundant because once you first installed the gauge it is pre the adjustable fuel regulator, so that should be the immediate tell tale that your fuel pump is maxed out at what the first reading shows. The only way the regulator works is to dampen or “retard” fuel pressure beyond the pumps max capacity. The regulator will not increase pressure beyond what the pump puts out.

What’s the part number for the adapter to add the pressure gauge?

Super well done video, a little above my pay grade and motto of if it ain't broke.................. lol

My thoughts on inching the fuel pressure up: There is a long way from the in-tank pump to the fuel pressure measuring point. There are quite a few kinks on the original line, and the diameter is as small as GM could get away with. every kink detracts a little line pressure. Increasing the diameter of the fuel line, most of the way, will open up flow, minimizing pressure drop. Just a thought. Install a measurement point near the pump, would of course show if there are any gains to expect.

I dont know why but sometimes the hole is already in the throttle body and you dont have to drill it for the screw. Also to remove the injector pod you can get away with only removing one fuel fitting.

Never realized your car was auto. Great video by the way.

Any recommendations for a fuel pressure gauge for 1994 GM 454 TBI? Fuel pressure on my RV is 26-32psi. FYI...at 11:05 your forgot to mention installing the TBI base gasket. best to install the adapter fitting first to make it easier to decide which port to install the gauge in. I don't recommend installing a permanent gauge. The heat will skew the gauge reading with time. Better to install a fuel rated schrader valve in one of the ports.

really wish there was part numbers

I've got a completely rebuilt TBI setup for a 350, manifold, Distributor, 193 64cc ported heads w/ SS valves new seals etc, I switched to a carb. I need money for surgery and need to get rid of some parts if your interested.

Hello, please write part numbers of fitting and manometer. Thank you.

Hi guys Is it possible to bypass the integrated fuel pressure regulator for using an external type? Thanks

Already watched your rebuild vid. and purchased TBI rebuild kit. Now that winter is starting here in the PNW can bench TBI for my '91 Vert. considering installing this at the same time. Do I order this from Summit, or? Thx

I don’t miss my TBI 305 in the slightest for my LS1/T56.

good discribtion... nice thx...did you adjust the pressure?

Would it be better to keep, rebuild and upgrade TBI or just do the carb swap if I am going to do work on the engine? I am for sure upgrading the cam and lifters and reolacing springs in heads may also try to swap vortec heads and in the future want to get a drop in 383 kit and rebuild. Not sure if im wasting my time by trying to stick with TBI.

I’m trying to do the same for my 454 tbi I was wondering where can I get that fuel pressure regulator and the custom fuel line adapter with the fuel gauge?

Any idea how to remove the idle adjuster plug (?) and install a/the T-27 torx screw? Thank You!

So what’s keeping the newly installed pressure screw in place? I heard no mention of tapping threads into the throttle body.

Hey cool vid, but ah what about the link for the parts eh? I don't see it maybe I need glasses.

I have a 95 silverado with a 305 what part number or were can i buy this kit from

Did you check the o ring on the fuel line itself I have the same problem with mine

You don’t have to remove brake booster line

I would like a bluetooth remote guage into the cab something like that. This way under load throttling if at times you see a drop in pressure to 7 pounds say, you can figure out way, maybe there is enough pressure while your watching but not while driving.

Hello I could be wrong but your fuel pressure regulator is located after the fuel pressure gauge so it's not going to show a change in fuel pressure.

👍

I have a question, how much do you think an LS1/T56 swap would cost if I paid someone for the labor?

Just what I was waiting for the audio got quiet. At 13;25 is the part that I need, but I don't know what it's called. I took pictures and no one knows at the part stores. Please someone tell me what that ring is called.

There's a new spring you can get that takes it to 13-14 psi, anyone tried it? Apparently it's works very well

Did you realign the inlet line in after installing the adapter? The adapter is longer than the OE one which will alter the line angle coming in. Likely enough that the O-ring isn't able to seal. Line needs to come in as straight as possible. You can follow the line back to the first bracket and disconnect it which likely will give you some wiggle room.

Please help me find the adapter for the gauge ???

the port that you had the gauge on had a oring already on it from the first time around

So the pump can't produce more than 11psi. So now we know this is a wasted exercise. Thanks!! Stick with a stock regulator.

Knowing what pressure the pump is giving the TBI is great but how do we know what the regulator is sending to the injectors. You now have it adjustable without any way of knowing what it is???

So essentially it’s the same as it was

Does this mod help with the map sensor pushing too much fuel? I have a 93 350 with a mild cam and I'm having issues flooding out...

Fuel pressure should hold key off. I think your fuel pump isolator is leaking, replace it with fi hose.

And now the supercharger

Can you leave this gauge system connected? And where can i get one for my 87 chevy 350?

you just as well as buy a rebuild kit put new o rings and screens and everything in the injectors your already there

Might be crazy but if it’s leaking with the gauge. Get some good thread tape like you use on a shower head to keep the water from leaking.

What does increased fuel pressure do for this TBI setup?

Cool, but what good is the mod if it is going to leak.Couldn’t even use the gauge.

Do you happen to know if this mod will pass emissions (smog)?

Where did you get that adapter???

Very good video I use Teflon on gas lines 👌

Where do u get that kit

You remember what kind of adapter that is that the fuel pressure gauge is going into ?

Where do I get this kit?

We’re u buy that part

Change it to a 4bbl carburetor or EFI. Too much trouble on a TBI.

After all this, did you manage to increase the fuel pressure at all or was it already at its peak before installing the adjustable fitting?

It looks like your injectors are shot. I don't think they should be spraying that much fuel, should be a fine mist instead. I had that same issue with my 93 GMC. You might get more fuel pressure if your injectors were replaced with ones that spray correctly.

Do you have links to the products talked about in this video?

Just get a fuel pump for a 97 c1500 and you will have plenty

У меня на 4.3 показывает давление 0 ,но работает

t.y.

Stop using a knife to clean gasket edges, use a dremel with a wirewheel; goes by A HECK of a lot faster lol ta ta 👋

What benefits does higher or lower fuel pressure provide and why did you want it adjustable?

so you spent how much money and all the time to do this and you get the same pressure as you did before ? maybe if you want more pressure you need a pump that puts out more pressure to start with in the first place . SO what did we learn here ? CAN ANYONE PLEASE EXPLAIN ??

So pretty much you did all that for nothing good job

so what the hell was the purpose the pump can only supply so much thats def a waste of time in my books

How is fuel mileage affected if you raise your fuel pressure from 9 to 12?

Ultimate mod? The regulator leaked and the fuel pressure went from 11 to 11. I'm not sure why we watched this😂😂

Teflon tape

A fuel pump from a 96 suburban should fix that problem

Ultimate TBI mod that didn't work...

another words-- a total waist of time