fuel pump question

Cat make pretty good gauges, bit pricy though, you can also get the quick connect fitting to plug it onto the filter base fitting from them.

 

I am wondering if you guys are using feul pressure readings with hot/warm feul?That would make a difference,just curious.

 

Does the factory cat test port for the fuel test pressure after or before the filters?

 

On my 3406E on the filter houseing with the primer pump ther is a plug, it take a 3/8 boss Oring fitting i think

 

On a C-15 the factory test port on top of the secondary filter base is after the primary filter but before the secondary filter but it can be move to after the secondary filter, if you look at the filter base there is an allen key plug on the outlet port to the cyinder head, you can swap this plug with test port as they are the same thread.

 

Ok thats good to know then. Thanks!

 

Maybe a dumb question, but if a truck is testing at 90psi @1800rpm, what actual improvements will a person experience by raising it to, say for example, 110psi?

Thanks

Cam

 

Not sure exactly but I think it would help keep a more constant pressure across the rail.That would be about a 20% increase.But I do know u need to make sure your getting a good flow from primary filter first.

 

oops, help. I went to install the updated spring and the plunger fell to the ground... Does the long end go in first, or does the long end of the plunger point out and into the spring???

thx,
jj Gonzo

 

Don't for get that all you are doing is raising the common (all injectors are always fed the same fuel at an even rate) fuel rail pressure. Same effect as Dodge Cummins CR 5.9L....Edge Pressure Boxes.....more 110psi fuel can get through a given port size and duration than what you would get if that fuel pressure was only 78psi.

Truthfully the noticable low is 78 psi and high is 110psi. So from 600RPM to 2100RPM there is not a huge reliance on shoving more fuel into the mechanicly compressed injector. The point is to shove 85gpm to each injector and each injector only needs .2gpm. And by doing so you have a very even supply of fuel to all injectors.

My analagies are odd some times but let me know if you want clarification on my understanding of the operation of the fuel transfer pump.

While this is a valid improvment for most, it can also cover up other problems that rob your power and cost you excess fuel.

More improvment is seen from the $25 Fuel Pressure regulator.