94dodgeman

Ok so i took a look at the link and wached the video. Maybe (just a thought) cound i pull the overflow valve out and clen it? Maybe it has some gunk in it. Can i clean it with some carb clean and put it back in? One thing i noticed is that when i bled the system i cracked the top bolt on the main fuel line into the pump to get the air out that it driped out. When i did it before it would pour out when we primed it.

gorms

Usually the problem with those is the spring gets weak over time. Cleaning it out/stretching the spring might be a temporary bandaid, but how do you know without knowing fuel pressure? Check your fuel pressure! Cheap gauge and parts from any tractor supply store or hardware store work fine.

Guess and check is not a good way to approach these trucks!

94dodgeman

Ill check my pressure but you might want to know that I found out some interesting info. I pulled the banjo bolt and looked at it just to see wat the spring looked like and such. Well come to find out there was nothing. No spring or anything just the bolt. I dont know if when i took the pump off if the spring came out. I didnt remember seeing it. But would this cause any of my problems? Pritty shure it would. What should i do with this one?

patdaly

Make sure you are looking at the right one, the one on the backside where the fuel returns......

Larryb - Overflow Valve for Dodge Cummins Diesel with Bosch P7100, 94-98.5

Cheap enough.

94dodgeman

Ya im looking at the right one. Its the one behind the pump between it and the intake part of the head. If the spring isnt there could that be causeing alot of my problems?

patdaly

Yes, yes it would........ You would have virtually zero fuel pressure at the P7100

On another thought, can you post a picture of the inlet banjo bolt on your setup? Have never heard of it, but could you have the OF on the inlet? ( I haven't researched if the thread sizes are the same...)

gorms

Just so happens I've got a few varieties of banjo bolts/overflow valves in the garage...





From left to right;
-Larry B's standard o/f valve, one peice sealed
-Stock o/f valve, assembled
-Stock o/f valve, disassembled
-Stock inlet banjo bolt. This is the one you drill w/ 5/16 bit and tap 1/8 NPT for permanent fuel pressure gauge.

Torktek adjustable overflow looks similar to stock. And yes all have same thread sizes.

94dodgeman

Thanks guys for replying to me on easter. Hope your holiday is going great and your eating lots! I just baught the one peice overflow valve. Im gonna take a look and see if i can find the spring and ball and if i can get it back together and it works i can put the hood and such back on and then just replace it with the new one when it comes. You've all been such a good help in this whole endeavor. Ill let you know if it fixs the problem. Thanks. Ill get some pics.

patdaly

94dodgeman, look at your inlet bolt and make SURE it looks like the one to the far right. Even if you get the right OF valve in the correct location, IF you happened to get the old OFV in the inlet position, you would cause pressure to be built up before the IP, not in it as is required.

That make sense?

94dodgeman

Got it makes sence. I checked the inlet and outlet and i did have them backwards but i changed it and the problems still happen. Just waiting for the mail and then we will see if the new ofv works.

patdaly

Cool, Lets hope for the best. I have a good feeling about this one.

94dodgeman

Ya i hope so. We have narrowed it down to the little things. Im gonna be ecstatic if i change the ofv and it fixs the issue.

94dodgeman

Well i got the overflow valve in the mail today. I put it in and started the truck up it took a couple cranks. I see no real diverence in the trucks performance. Very slight if anything. So now i have to check the fuel pressure? If i find that the pressure is wrong then what does that mean
. I have to change my fuel pump? Thanks.

patdaly

Get your pressure gauge on, if it isn't 25-27 at idle and 35ish going down the road with throttle, then you need to pinch off the rubber part of teh return line, don;t do it all the way, just a bit should be enough to significantly raise the fuel pressure, if it does, then you know the lift pump is OK, if it doesn't hit 60 PSI pretty quickly, then it is time for either a lift pump or find out why it isn't pumping enough fuel to the P7100.

94dodgeman

Alright. Ill go ahead and try that and ill let you know how it goes. As far as i know the lift pump is original to the truck, and the truck has a little over 200000. It would surprize me if it was bad. I might have finished of the pump when i put the governor springs in.