TBI fuel pressure limit?

[strokersix]

How much fuel pressure can an OEM TBI fuel injector handle? What will happen if that pressure is exceeded? What are the tradeoffs involved with regard to performance and durability?

 

[strokersix]

I'm interested in late 1980's early 1990's vintage General Motors throttle body injection systems such as would be installed on a Chevy pickup truck 2 barrel system or on a compact car 4 cylinder 1 barrel system. Also interested in aftermarket systems such as Holley Pro-Jection.

I understand that some TBI pressure regulators use intake manifold pressure for reference. If this is correct could someone please comment on which systems use this reference pressure and why some systems do and some do not?

Thanks.

 

[nagy]

Ok, let´s star for the begining; as I understand you are talking about SPI ( single point injection). On this type of system the injector is positioned upstream of the butterfly and use no intake manifold pressure compensation , because the injector is at atmosferic pressure.
In this type of injector(side feed ) we normally use a pressure of 1 bar at a maximun of 1.5 bar ( because a O´Ring pressure restriction )

For a MPFI( top feed ) injector the normal work pressure is around 3 bar and on this kind of system you normally use a intake manifold pressure compensation , because you have a delta pressure on the nose of the injector( the pressure at the nose of the injector vary , it depend of the motoristic condiction.May be you can find this system without a compensation , because they do this by software.

In this type of injector we can go at 5 bar may be until 7 bar ( because a Electric magnetic force generated by the injector coil could not be enough to open it or because a pump and hose limitation )


nagy