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TBI regulator spring

4X4HIGH

4X4HIGH

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Does anyone know what pressures are attained with the different color springs? I have a spring from a 454 TBI that is a yellowish/orangeish color. The trottle body is supposed to be from a 1989 454 and i believe that to be true as the injectors are date coded for 1989.
 
4X4HIGH said:
Does anyone know what pressures are attained with the different color springs? I have a spring from a 454 TBI that is a yellowish/orangeish color. The trottle body is supposed to be from a 1989 454 and i believe that to be true as the injectors are date coded for 1989.
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Is this going on a 454? I tried to use a vrfpr on a 355 and it way over fueled because of the 454 spring. Have you considered using a vrfpr?
 
It is a 454 going onto my built 355. I have already talked with Brian at TBIchips and he said i'll need the 454 injectors GM5235231 which i just had cleaned and tested. I just don't want ot have to much regulator spring since i heard there were several different ones. I also have already searched for a VRFPR and the number i came up with has been discontiued.

FWIW, i decided to take my 350 TBI apart to verify that the 454 spring is the same (and it is). Hopefully i'll be good now. I also drilled out the regulator and made it adjustable as well.
 
4X4HIGH said:
It is a 454 going onto my built 355. I have already talked with Brian at TBIchips and he said i'll need the 454 injectors GM5235231 which i just had cleaned and tested. I just don't want ot have to much regulator spring since i heard there were several different ones. I also have already searched for a VRFPR and the number i came up with has been discontiued.

FWIW, i decided to take my 350 TBI apart to verify that the 454 spring is the same (and it is). Hopefully i'll be good now. I also drilled out the regulator and made it adjustable as well.
Click to expand...
I'm not sure about a stock FPR but the vrfpr has a much heavier spring than a stock 350 fpr and can't be used. There's a few threads about it on thirdgen.
I got mine from GMperformanceparts i think? If you want one and they are discontinued, I have a new one. I think I fitted it up but never actually ran it because of the spring issue.
 
Do you have any idea how much pressure the stock spring will give when adjusted at it's highest point (assuming the fuel pump i have can handle the extra pressure)? I don't have any specs on my pump at the moment (i'm going to look for the part number and check).

EDIT: i have an airtex pump and the specs are 35 GPH wide open and 12-17 PSI. I'm sure this pump will at least get me to 15psi but i'll look into a different pump with a higher GPH/PSI after i have the truck running again and see what this pump is capable of.
 
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As far as I know, with a stock TBI pump, it's possible to get 19psi through the TB so I guess you'd get full pressure from your pump.
 
I just got off the phone with Brian at TBIchips and just placed my order for a chip and also a 255LPH fuel pump as well.
 
So what are you going to do about your regulator? Try your stock one? Just curious.
 
southernspeed said:
So what are you going to do about your regulator? Try your stock one? Just curious.
Click to expand...

I modified my stock regulator making it adjustable. At the current 13psi that it was running at the regulator was half way between the range of adjustment so i should be able to get 20 psi with the stock spring. If not then i just need to buy the 18psi spring from TBIchips.
 
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