Fuel pressure and restriction test

[DDlighttruck]

   

Cm870

I went to Quickserve and printed off the fuel inlet restriction test, the fuel filter (spin on) test, and the fuel pump test

[DDlighttruck]

         

There’s a compucheck fitting down by the metering actuator. Pressure was 240-320 roughly, it wouldn’t pick one spot, the needle just bounced around.

The needle pegged on the restriction gauge

[DDlighttruck]

         

Up at the IFSM is a second port. There I get 12-13 inches of restriction and about 50 psi fuel pressure

I’m going to get new fuel filters tomorrow and retest.

Does that sound like I’m doing it right? All tests were done at idle, so roughly 600 rpm

[DDlighttruck]

   

Also- how do I know if I have a fuel inlet pre-filter?

[Evotrucker]

(11-29-2019 )DDlighttruck Wrote:  Also- how do I know if I have a fuel inlet pre-filter?

i asked the same question on a post i made or in the thread a while back.

It should be where the inlet side of the IFSM is connected to pick up the fuel.

Some of the guys have it and some dont? i think if i remember correctly rawze said that 300 micron filter is junk? lol. It caused fuel restrictions if im not mistake also about that.

[DDlighttruck]

(11-30-2019 )Evotrucker Wrote:  

(11-29-2019 )DDlighttruck Wrote:  Also- how do I know if I have a fuel inlet pre-filter?

i asked the same question on a post i made or in the thread a while back.

It should be where the inlet side of the IFSM is connected to pick up the fuel.

Some of the guys have it and some dont? i think if i remember correctly rawze said that 300 micron filter is junk? lol. It caused fuel restrictions if im not mistake also about that.

I guess I’ll pull it apart tomorrow and look inside. Thanks

[DDlighttruck]

I picked up new Fleetguard filters, a ten micron for the Davco and a regular FS2200 spin on. I really want to get after this tomorrow

There is next to no instructions with the fuel pressure gauge. I still find it hard to believe it dropped from 260-ish at the bottom port down to 40 at the top port. If it’s still the same after changing filters and looking for an inlet screen filter I’ll take it in somewhere to get a second set of eyes on it

[Lonestar10]

bottom port is supply from gear pump top port is suction of the gear pump so there will be a large difference in pressure.

[Signature620]

That restriction gauge cannot be trusted now that it has been exposed to over 200psi. Never put a manual restriction gauge where there is pressure. They are for the suction side only (from the tank to the compuchek fitting at the gear pump) and should be used only after the lift pump is unplugged.