IP question

[The_Josh_Bear]

I don't know enough of how a Holley blue works to help out with that side of things.

Today I finally figured out why my rear tank won't run any amount of WMO at all, and it was a chunk of crap at the inlet to the FSV! I can't remember if you deleted yours yet, but it had all the same symptoms you're talking about, except mine wouldn't run longer than a few mins even at idle. No driving around. Yet with straight diesel I could drive around months ago, so maybe it was introduced somehow in that span of time. It's not impossible.

 

[IDIBRONCO]

I can't remember if you deleted yours yet

Yes. I bypassed it back in 2016. If I can't fuel pressure after installing a regulator return, I can only think of two options. Run an entire new piece of hose from the pump to the filter right before the pressure sender, and try pulling fuel from the rear tank to see how it runs. I can't run like that for very long since it returns to the front tank. Of course if it runs good that way, I'll reroute the return back to the rear tank. I'll have to be CAREFUL that way since there's no gauge for that tank. In the spring, I HAVE to do a lot of clean up work to this truck so it just has to run until then.

 

[IDIBRONCO]

I did find a ride into town yesterday. I got what I really needed. Today, after work, I hooked up a bypass line to the second out feed on my regulator. The return was ran into the feed line before the Holley. I turned on the key, and...NOTHING! 0 PSI on the gauge. I did some reading on the instructions and found out that there's three regulators for the blue pump. One has one outlet, one has two, and the last has one and one bypass. Just for kicks, I switched the bypass and engine feed hoses around and got the same result. At least I now know that I do NOT have a bypass regulator, but one with dual outlets. A quick plugging off of the bypass hose and the hose that T's into the pump feed, and I now have exactly the same thing that I did before I started messing around with the truck today. Was it 1 1/2 hours of spinning my wheels or was it 1 1/2 hours of learning? I haven't decided. I guess I'll be letting this sit for a few days since the weather isn't supposed to be exactly balmy. I am now glad that I got inspired this morning and ordered another mechanical lift pump to install just in case this Holley turns out to be junk right out of the box. Another thing to try will be to bypass the regulator and feed fuel straight from the Holley to the pressure gauge. The pump is supposed to be set at 14 PSI from the factory and if it can't make that, then it's probably bad.

 

[IDIBRONCO]

Right now, I'm calling a semi success. I pulled a muscle in my right hip, somehow, on Friday at work. I didn't do anything yesterday, but I did have an idea. I knew that the regulator was all the way closed for lower PSI. I was only concentrating on the pressure and not the volume. This pump is designed for engines with a carburetor which only have a feed to the engine and not a return. So I went out and turned the regulator up to let more fuel through and it sort of worked. I let the engine idle for almost 25 minutes and the fuel pressure was still at 7 PSI. I drove around town a little bit and then hit the highway. By the time that I was going 70 MPH, I was down to 0 PSI again. I stopped alongside the road and opened the regulator a little more. Better. I did the same when I go to a point to turn around. It took me until I was almost back down to 0 PSI. In my driveway, I opened it almost all the way so now there's only about 1 1/2 threads showing on the adjuster nut. I'm starting to think that this regulator just can't keep up with the amount of fuel that this engine needs. As long as I can limp it along for now, I'm happy. I'm starting to think that I might need to try my Holley black or switch entirely over to a Walboro set up. As long as I can drive around fairly locally, I can manage. This also means that I need to concentrate on getting my Red Truck up and running again.

 

[Nero]

In my experience older diesels, not just these ones, require low pressure but higher volume, mostly for pump lubrication and cooling. Newer engines are able to get away with much smaller fuel lines to the tank. Just some food for thought.

 

[IDIBRONCO]

In my experience older diesels, not just these ones, require low pressure but higher volume, mostly for pump lubrication and cooling. Newer engines are able to get away with much smaller fuel lines to the tank. Just some food for thought.

Well here's my update. I decided to go for a drive to test it out. Before I left I opened the regulator all the way up just because. I only drove about 2 miles at 70 MPH before the gauge was reading 0. I managed to barely keep it reading positive pressure by staying in 5th and driving 50-55. By the time that I got to tow, 20 miles away, it still was reading 0 but ran fine. Pulling up to a stop sign or a red light didn't make the gauge read any higher. That, plus driving around town where the speed limit is 30 MPH, should have made the gauge read at least 6 PSI since it's rated at 4-9 PSI. After ******** of the engine and restarting it again, the gauge might read 5 PSI, but would be back to 0 before I left the parking lot which shouldn't happen since I drive through those at maybe 1200 RPM. By the time that I left town, I had decided to drive by the speedometer and not the fuel pressure gauge. About 10 miles was at 60, the other 10 miles was at 70 and I had no signs of running out of fuel at the IP despite that fact that the gauge was showing 0 PSI the entire time. Mind you, the location of the sender is like this. Rubber hose runs from the steel line at the frame, to the passenger's side inner fender, to a universal 3/8" filter, to the sender, and the to the factory hard line to the filter where I cut it off below the elbow to start this process. At worst, it should have read SOMETHING. It does read pressure upon cold start and then the pressure will eventually drop.
What did happen on the way home was this. While driving 60, I couldn't tell any difference. While driving 70, there is one bigger hill, not too tall or steep, but more than just a rise. I had trouble keeping speed up that hill. Afterward is about 3 miles of pretty flat ground. Just because, I put the pedal down around 3/4 of the way. I sped up to 80, but it took a while to get there. I'm thinking that this is now like Cubey's RV after he installed the Holley red. The timing's so advanced that it just can't reach higher RPM without difficulty. The gauge is an Auto Meter. I paid WELL over $100 for it and it's a real downer that it doesn't seem to be working right. After two fuel gauges that don't work right, I'm starting to think that I need to find a fuel flow gauge instead of a pressure gauge.

 

[The_Josh_Bear]

Well here's my update. I decided to go for a drive to test it out. Before I left I opened the regulator all the way up just because. I only drove about 2 miles at 70 MPH before the gauge was reading 0. I managed to barely keep it reading positive pressure by staying in 5th and driving 50-55. By the time that I got to tow, 20 miles away, it still was reading 0 but ran fine. Pulling up to a stop sign or a red light didn't make the gauge read any higher. That, plus driving around town where the speed limit is 30 MPH, should have made the gauge read at least 6 PSI since it's rated at 4-9 PSI. After ******** of the engine and restarting it again, the gauge might read 5 PSI, but would be back to 0 before I left the parking lot which shouldn't happen since I drive through those at maybe 1200 RPM. By the time that I left town, I had decided to drive by the speedometer and not the fuel pressure gauge. About 10 miles was at 60, the other 10 miles was at 70 and I had no signs of running out of fuel at the IP despite that fact that the gauge was showing 0 PSI the entire time. Mind you, the location of the sender is like this. Rubber hose runs from the steel line at the frame, to the passenger's side inner fender, to a universal 3/8" filter, to the sender, and the to the factory hard line to the filter where I cut it off below the elbow to start this process. At worst, it should have read SOMETHING. It does read pressure upon cold start and then the pressure will eventually drop.
What did happen on the way home was this. While driving 60, I couldn't tell any difference. While driving 70, there is one bigger hill, not too tall or steep, but more than just a rise. I had trouble keeping speed up that hill. Afterward is about 3 miles of pretty flat ground. Just because, I put the pedal down around 3/4 of the way. I sped up to 80, but it took a while to get there. I'm thinking that this is now like Cubey's RV after he installed the Holley red. The timing's so advanced that it just can't reach higher RPM without difficulty. The gauge is an Auto Meter. I paid WELL over $100 for it and it's a real downer that it doesn't seem to be working right. After two fuel gauges that don't work right, I'm starting to think that I need to find a fuel flow gauge instead of a pressure gauge.

I put a small fuel manifold with about 12" of fuel line before the IP inlet. I have a mechanical gauge off that, plus the new digital gauge I just installed in the cab, and the factory bleed nipple(with the very small hole) going into the return tees. So I get pressure readings right there, and can pop the hood to verify with the mechanical as well. The ability to bleed off air is fantastic, and because of the check valves I've installed any drain-back is quite minimal. I run the e-pump until the cold advance turns off as well.

 

[IDIBRONCO]

That sounds like a good idea. Unfortunately, it's not going to happen for me right now. It would have to wait.

 

[IDIBRONCO]

ANNND the adventure's not over yet. I went for about a 70 mile round trip this evening and ran out of fuel again. Even with the Holley. Long story short, I had already decided to install the new mechanical lift pump before I ran out of fuel. I was lucky and went back by my garage where I had dropped off the lift pump. I almost called for a ride home when I remembered that the Holley's electric and was still making noise. I bled the air out of the filter and got the engine running again. I had a nice LOOONG drive back home in 4th gear at around 30MPH. Thursday's supposed to be nice so I know when I'll be installing the lift pump. The one slightly good thing is that maybe the Auto Meter gauge isn't a P O S after all.

 

[IDIBRONCO]

I didn't get finished today. It was pretty windy and I got tired of the wind blowing dead grass and other crap into my eyes. I did get the lift pump changed and the vacuum pump back in place. I still have to reattach the ground and starter cables to the engine. I have a rubber hose running from the feed on the tank to the pump to eliminate the factory connection. I've decided to run another one from that hose to the lift pump to completely eliminate the rest of the factory lines. Since it's only supposed to be in the mid 30's tomorrow, I doubt that I'll feel like messing with it after work. It looks like Saturday will be the next day for me to work on this.

 

[klook]

Following this with great interest. I am going to be digging into mine soon. I cut a hatch in the floor of the Ambulance to access the fuel pickup. Starting at the tank and moving forward. Remote filter mount, new lines. I am wondering about the lift pump delete as mine is probably 32 years old. Considering the Facet pump? I still don't know what to expect when I start it up and take off. I do know that additives seem to help.

 

[IDIBRONCO]

The Facets don't have a very good reputation these days. They're not worth the bother.

 

[IDIBRONCO]

Another slight success. I finished installing the mechanical lift pump. I ran new fuel line from the tank to the lift pump. For whatever reason, the Glow Shift gauge decided to work today. At an idle, it was reading 1-1.5 PSI lower than the Auto Meter gauge. That's not bad considering that it's a Glow Shift, it's post filter, and the Auto Meter is pre filter. Thinking ahead, I started the engine and let it run for 20 minutes before disconnecting the fuel from the Holley and putting it to the new lift pump. Afterward, the engine started right up. The Auto Meter gauge was showing around 9PSI at an idle which seems pretty high to me. On a 8 miles round trip test drove, the gauge was showing 0 PSI by the time that I got back to town. This, now, is EXTREMELY puzzling. The only thing left that's not new between the tank and the fuel filter is the sender itself, and that seemed to be good as far as I could test it. There must be something that I'm missing, but I just can't figure out what it is.

 

[IDIBRONCO]

I've made the decision to try to limp over to my garage tomorrow. I have another IP or two laying around that I want to install. I really don't know what else to try. Both the Holley and the Carter mechanical pump get good fuel pressure at start up. They both keep good pressure while idling, today was 20 minutes and the Holley was still showing 8PSI. After the engine runs for long enough to lose fuel pressure, the fuel pressure won't build back up even at an idle. If I shut the engine off for a short time, the Holley will build some fuel pressure, but certainly not what it does while the engine's cold. I'm thinking that, due to the original lift pump (when the trouble started) not being able to supply enough fuel, the IP wasn't able to keep itself cool during my LOOOONG trip back from Byers, CO last summer. My guess is that something inside is worn enough to either let too much fuel back out the return or something(?). That's just a theory right now. I will be bringing along my Holley black and regulator just in case.

 

[IDIBRONCO]

Last Sunday, I had a bad headache all day so I didn't even attempt to do anything to the truck. Then I got so frustrated with it that I said "F this POS!" and didn't do anything to it until today. I know, it was stupid, but it happens.
During the time that I wasn't working on it, I got to thinking that I may not be able to make it to my garage with a mechanical lift pump. I started out today intending to install my Holley black. As I was getting everything ready, I remembered that everything else on this project had taken longer than I thought it would and I REALLY wanted to swap IPs today. Tomorrow may have been ok. It's supposed to be in the 50s, but with 25+MPH winds and that's no fun to work in. I plumbed the Holley blue back in and went to my garage. I got the IPs swapped out, the one that I used was still on the engine in the F Superduty that I bought last summer. I hadn't noticed before, but the IP looks like it's been gone through fairly recently. I did notice some uncool things about it, but I went ahead anyway. When I pulled the top off of the "new" IP, it all looked clean inside so I dumped out the fuel, filled it with ATF, and put the top back on. I removed the IP from my truck and swapped the other one on. I may nave tightened the line nuts half way down on the injectors because, why should I go any tighter? I cranked the starter over for a 15 count with the throttle to the floor and let the starter rest. Amazingly, there was fuel at all 8 injectors so I tightened the nuts all the way and started the engine. It started great and took no time at all to bleed the air out of the system. It performed really well on the way home so I'm going to call it at least a 90% SUCCESS. I say 90% just because I want to keep an eye on the Holley for a while and I know nothing about the IP. I kept 10-12 PSI on the fuel pressure gauge all the way home except for going up hills. The lowest I got it was 9.75 PSI on the biggest hill while holding 75MPH. So far, I'm very happy. Now the real test will be tomorrow when I start the truck cold. I'll get to see how it starts without a seal that leaks on the IP when it gets cold outside.