Superduty

"with a access hole in the center of the it"

If I screw a gauge into the access hole in the center of a Geno filter lid, does that connect with the fuel volume in the center of the filter or the fuel volume on the outside of the filter ?

I used the term "tap" in my previous post meaning "a connection to".

What am I not undertanding here ?

FWIW, I think the stock plastic filter cap could be drilled and tapped as well. I was going to do it, but I wanted pre filter pressures, not post filter pressures.

Superduty

"BC, look at your fuel filter and if it has no opening on the top of it, the cap will give you pre-filter pressure."

ooohhhhh.... I get it now...

The top of the filter is closed in on the Dodges. Thus even though the filter tap (hole) is in the center of the lid, it is still reading the pressure from the outside of the filter.

The hole in the center of the cap doesn't connect to the center volume of the fuel filter !

I've looked at the fuel filter. I was confusing it with other filters. Now I remember. The Dodge filter is closed in on the top.

I get it.

Thanks for pointing that out.

I smell another mod in the works... a pre filter fuel pressure tap on the stock filter lid.

george7941

SD. The reason the lift pump power is reduced during cranking on 2nd gen. trucks has nothing to do with deadheading the LP. It is because full pressure to the VP causes hard starts due to overadvanced timing inside the VP. So the ECM runs the LP at half voltage during cranking and, once the engine starts up, supplies full voltage to the LP.

Superduty

Good to know. Thanks George. I'll post this in the 2nd gen thread about implementing a Walbro.

george7941

One more thing, SD. Since you do not own a 2nd gen truck you are understandably not familiar with it but the VP does have an internal lift pump which is what causes it to self-destruct when the LP fails because it is able to draw enough fuel to keep the engine running but not enough to keep itself cool and well lubricated.

Geico266

Hence the reason for an oil pressure swtich to use with an aftermarket LP.

Superduty

I/we figured that part out George. We are discussing it over in 1st/2nd gen performance. Last night someone enlightened us. Now I see how similar the CP3 and VP44 feed systems need to be.

Thanks again, George.

Geico: Is that truck still sitting in the driveway waiting for a fuel pump ? For a man with a FASS on order, you sure are interested in Walbros. Me thinks you could have a Walbro in that thing pretty quick. We both know you are going to do, so why don't you just come clean. If you order it tonight on eBay you can have it for the weekend. Your FASS order won't get completed for another week.

You might want to consider this too:
http://www.turbodieselregister.com/f...d.php?t=148908

Geico: tell us more about how you would use the oil pressure switch to assist with over pressuring during startup. I'm curious. Keep in mind the Walbros are probably going to run from a relay, not the ECM directly.

I was thinking of a voltage dropping resistor used to power the pump when the key is in the crank position. In the run position it could get the normal battery voltage.

Geico266

Don't know where you get your information, but my truck just completed at 150 mile run at 80 mph to Omaha & back to pick up parts for a job. As for the FASS is was shipped Monday, got here this afternoon while I was on the run. What are you smoking on your time off watching your wife gestate?

jthorpe

We just never learn, do we?