Mr. Jimmy

Infidel,
I read your write up and have looked at the picture on drilling the banjo bolt for fuel pressure gauge but not clear on where to drill and tap. It looks like I need to remove the bolt and drill thru the center of the bolt head. Is this correct? How far down do I need to drill?








95/CC/CTD/4WD/Auto/Isspro gauges

infidel

You need to remove the banjo bolt, 19mm, don't loose the sealing washers then drill up though the center with the biggest bit that will fit though the center. You will be drilling though the bolt head. Then tap in to 1/8" NPT from the top. I would say a vice isn't optional.
What I've found with some banjos is the center of the bolt isn't big enough for a 1/8" tap, most are exactly the right size though. If it's too small for the tap just enlarge the hole to the correct size by drilling down from the top of the bolt head about 1/2".
These bolts are hard steel, use oil when tapping and turn the tap back about a quarter turn for every half turn forward to dislodge chips.
Clean the bolt off well before reinstalling, you are on the clean side of the filter.
I usually install the needle valve most of the way tight before installing the banjo, makes it easier to get the threads started straight. Once the banjo bolt is tightened down tighten the valve to get the handle in a position you can access. Don't get carried away tightening the banjo or you will break it.
On some needle valves a 1/4" or so of each end of the handle needs to be cut off to allow the valve to turn, wire cutters work for me.
Use Permatex #2 or anti-seize for pipe dope on the valve and other connections but nothing on the banjo threads, the washers do the sealing on it.

First start after doing the work will be a little hard, floor it while cranking. It will run rough for a few seconds then pull out of it.

Mr. Jimmy

Sounds easy enough..thanks infidel.. I'll let ya'll know how the project goes. I also plan on sliding my stock plate forward this weekend. I have decided to give this a try, instead of a #10 plate, until I get the funds for the Goerend transmission.My stock trans. is pulling good right now and fishing season is close, so don't want to screw that up, I need the truck to pull my boat. We are supposed to have some nasty weather this weekend so I might as well spend it in the garage

Mr. Jimmy

I noticed tonight while sliding my fuel plate that the POS Primeloc does have a port for a fuel press. gauge. Maybe something positive will come out of having one, on second thought, it will probably just pinch my fuel pressure line everytime I need to remove it to get to something else...oh well back to the banjo bolt

infidel

I'm not really sure how the pressure gauge port on a Prime-Loc is plumbed. The gauge that usually goes there is a differential pressure gauge. That means it is somehow connected to both pre and post filter. Every gauge I've seen has been broken, Prime-Loc wants something like $40 for the funky little gauge that has no numbers, just color zones.

Mr. Jimmy

Got the fuel press. gauge installed but I think I need to do some adjusting on the needle valve. The gauge is showing 20-22 PSI idling and driving. Shouldn't I be getting more pressure at higher RPM's? Didn't want to crank the needle valve to far and blow the gauge.
Also blocked the wastegate and now I'm getting about 25 pounds of boost, seems to make the EGT's run a little cooler.

infidel

Your numbers are ok but unusual, normally the fp would rise with rpm.
So did you tap the banjo? I'm not sure of the results using the Prime-Loc port.

Does the gauge go to zero when you turn the truck off?

Mr. Jimmy

I tapped the banjo and used a 0-100 PSI, AMI fuel press gauge from surplus center, didn't want to take a chance on blowing the gauge so I decided not to use the Primeloc port. The gauge does go to zero when truck isn't running. The truck runs fine with these readings. I will change the filter and see if the numbers change any. I also plan on doing some more adjusting on the needle valve and see what happens. I guess the worst case scenario would be blowing my $10 gauge I think I will order a spare banjo bolt just to have on hand in case the drilled one cracks while out of town pulling a trailer. Does anyone know the Cummins part number for these?
Got to go cut more firewood today and move a storage building for a friend, so no time to play.

wannadiesel

You will know you have the valve open too far when the needle in the gauge starts to blur a little.

infidel

and if closed too far the gauge will be slow to come up and slow to go down at shutdown.
Problem could be that because you are only using the lower portion of the 100 psi gauge that it isn't accurate. Better if the gauge reads in the middle of the range. Keep your eyes on surplus center and $10 AMI 60psi gauges will eventually show up.

Mr. Jimmy

I have noticed that the gauge is slow to come up. I'll have time to play with it after work tomorrow.

Mr. Jimmy

Infidel,
I did get the gauge to bounce and then turned the needle valve back down just enough to get a steady reading this afternoon. I changed the fuel filter just to see what would happen. The pressure is still at 20-22 PSI at idle and driving speeds. Do you think that the OF valve could be causing the low pressure condition or do I just need to go ahead and order a lift pump? I plan on pinching the return line and see what happens but didn't know about this until I did some reading tonight. The FSM says minimium of 25 PSI before filter. I am checking after filter so I'm thinking maybe I should see some drop across the filter. The truck runs great but don't want to be caught with my pants down..

JKM

If you need a lift pump , watch ebay , there was a brand new one the other day for 75$

Mr. Jimmy

thanks JKM! I'll check tonight.

infidel

Jimmy, never ran into a situation like you describe.
Personally what I would do is buy an extra OF valve to carry with you and not mess with anything as long as the truck is running good.