Aeromotive fuel pressure regulator boost reference line. - Diesel Forum

TimC63 · 01-12-2007, 03:28 PM

Is it possible to have a runaway engine situation if the diaphragm ruptured in the Aeromotive regulator?

I have found a performance gain when boost referencing the regulator in addition to a base pressure of 60-65 psi. I also used a very small orifice in the boost reference line. I just wonder if the engine could tach out to the point of damaging itself in the time it took for the fuel pressure to bleed down after shutting the key off.

Any thoughts?

God Bless,

TC

Afterthought: If you are running the boost line to the regulator, what base pressure are you running? I noticed someone else runs a lower base pressure with the boost reference...

Ford_Forgotton · 01-12-2007, 07:38 PM

The instructions that came with my ITP fuel system was to not use the boost reference port.

In fact, they include a "blowdown" line to run from the boost port, over the engine, and down to the fenderwell.

The boost reference diaphragm has fuel on one side of it, and if it should rupture, fuel would spray out the boost port. The blowdown line is therefore needed as a safety to direct fuel away from the motor.

TimC63 · 01-12-2007, 11:57 PM

Thanks Daryl!

I know Aeromotive's website says to route a hose to a safe dumping location if you don't boost reference the regulator too.

TC

On Edit: I jacked the fuel pressure about 5 psi and hooked up the boost reference at the same time and got nice results. Maybe I could get by with just the higher fuel pressure... something to try!

richmondfarms · 01-13-2007, 12:12 AM

Tim, if the boost reference being hooked up makes a difference, then you must have a fuel delivery problem somewhere. You may want to get a mechanical gauge on the system that you can see while driving. If your pump can maintain 60 psi to the injectors that is all you will ever need, more pressure can not physically cause a performance gain, the injectors just don't work that way.

Ford_Forgotton · 01-13-2007, 12:19 AM

I agree, the boost reference line should have no effect on our diesels. Look at delivery issues instead, such as feed lines, and pressure drop off at higher RPMs.

I bought an autometer 0 to 100 electric gauge, that uses a sensor that looks very much like an ICP sensor (same plug in fact!) and monitor my fuel pressure in the cab.

I can drop my pressure to almost 40psi at WOT in first just before it shifts to second.

richmondfarms · 01-13-2007, 12:25 AM

[ QUOTE ]
The boost reference diaphragm has fuel on one side of it, and if it should rupture, fuel would spray out the boost port. The blowdown line is therefore needed as a safety to direct fuel away from the motor.

[/ QUOTE ]

Daryl, is this a hardline or a hose? This is a great safety idea!!!!

TimC63 · 01-13-2007, 12:26 AM

Thanks Pat and Daryl!

As I mentioned, I upped the base pressure from about 58 to 65 psi at the same time I boost referenced it. I will see if I can get by without the boost line, as the increased fuel pressure may have been all I needed.

Regarding monitoring the fuel pressure, the UPS truck delivered my digital gauge and senser from Dakota Digital today! I will get it temporarily installed tomorrow so I can watch fuel pressure on our trip to Ocean Shores. Unfortunately we aren't taking the trailer, which puts the real load on the ol' Stroke!

TC

richmondfarms · 01-13-2007, 02:09 AM

No trailer? Looks like you will have to improvise a load by using fast acceleration and high top speeds [img]/ubbthreads/images/graemlins/cool.gif[/img]

TimC63 · 01-13-2007, 02:25 PM

[img]/ubbthreads/images/graemlins/smile.gif[/img] [img]/ubbthreads/images/graemlins/smile.gif[/img] [img]/ubbthreads/images/graemlins/smile.gif[/img]

[ QUOTE ]
improvise a load by using fast acceleration and high top speeds

[/ QUOTE ]

Hahaa, while I do agree that is the universal answer in most all cases... (rates right up there with if it ain't broke fix it til it is..) the wife doesn't appreciate that when we have all the kids on board, plus we still have some packed snow and ice on the roads up North of Seattle! We are up to a balmy 25 degrees today!

Take care!

TC

**DIESELDUTTON** · 01-13-2007, 03:21 PM

I know you might not need it anymore but, I work on boats and some boat builders use a electric anti siphon valve in the fuel system , when the ignition is powered up the valve opens, its probably overkill but could be used it would also have to be reduced from 1\4 npt.
Frank

Ford_Forgotton · 01-14-2007, 12:49 AM

[ QUOTE ]
[ QUOTE ]
The boost reference diaphragm has fuel on one side of it, and if it should rupture, fuel would spray out the boost port. The blowdown line is therefore needed as a safety to direct fuel away from the motor.

[/ QUOTE ]

Daryl, is this a hardline or a hose? This is a great safety idea!!!!

[/ QUOTE ]

Its a very stiff plastic line. Tiny. Barely fits over the nipple of the boost port. Its just there to direct any POTENTIAL fluid away from the motor. Its not much different than boost gauge tubing, just black, and large enough to get over the boost port.