Gary Lewis

Wow! Well done!

I'm not sure what points you are asking about. Can you post a larger pic?

One wire is probably the Yellow wire to Trailer Power as Dave suggested. Another might be the BK/W for the Camper. See the schematic below. And the third might be the one for the underhood light, and I don't have the color nor schematic to-hand.

Thanks, Bill. Wasn't aware of that.

Thanks, Shaun. I guess I've never been around one of those.

The park/turn lights have two separate circuits in them, as do the tail/brake lights. And about the only thing in common is the fuse and the ground. So it seems like there's a short somewhere.

Yes, the shifter looks short. I first thought it was the t-case shifter, but not so. Strange. $2K w/o a bed? Seems kind of high, but the truck looks fairly solid.

The Bullnose 460 air cleaners had a black base and an aluminum cover. But the 70's 460 air cleaners look like yours. And I like it. The whole thing looks "right".

Yes, the mechanical pump has to go. What I did was to put '96 tanks and FDM's in since you can still get those, and probably can for quite some time. That gives plenty of pressure for the EFI system. As for the 15 MPG, even with a 351W it is going to be a challenge with the C6. The unlocked torque converter and lack of OD makes it very inefficient. But I'm at about 13 with my heavy 4wd F250 and a 460/ZF5 combo, so it is possible to do better than 12. And the 400 in Dad's truck should easily do 14 or more with the E4OD. So it can be done.

I don't know the part number of the harness nor the connectors. But you should be able to splice yours back together.

Doesn't the Sniper require a higher-pressure pump? I thought all EFI systems do, which is one of the reasons I converted to a mid-90's system with the fuel delivery modules. Anyway, if you get that 460 to 15 MPG you'll be working a miracle.

I suspect that part of the problem is that you "are changing to an FS6 compressor" so it isn't the original unit in the system. But, I think we can figure it out. I don't have this section scanned in but will. However, I'll try to type in these snippets from the 1985 factory shop manual section on the FS6 Compressor And Clutch: When it is necessary to replace a component of the refrigerant system, the procedures here must be followed to assure that the total oil charge in the system is correct after the new part is installed. When the compressor is operated oil gradually leaves the compressor and is circulated through the system with the refrigerant. Eventually a balanced condition is reached in which a certain amount of oil is retained in the compressor and a certain amount is continually circulated. If a component is removed after the system has been operated a certain amount of oil will go with it. To maintain the original total oil charge it is necessary to compensate for this by replacing the oil in the new replacement part. A new service replacement FS6 compressor contains 10 fluid ounces of the specified refrigerant oil. Prior to installing the replacement compressor, drain four fluid ounces of refrigerant from the compressor. This will maintain the total system oil charge within the specified limits. So they want the FS6 to have 6 ounces in it, and yours has 3. I think you need to add 3.

That's an interesting comparison. And while 4 MPG sounds significant, it is actually a 50% increase when going from 8 to 12. And 12 MPG with a 460/C6 combo is excellent. I'm not at all surprised that the 4160's MPG was poor. Out of the box I've found 4160's to be quite rich. Also, I've seen the same problem of not being able to get a stable idle on a 4160. So I was betting the 4180's MPG would be better, although I didn't expect 50% better. I wonder what difference the EGR will make? Obviously it only comes in during high-vacuum conditions, but it might lean the 4160 out a bit.

Oops, posted before I was done. That switch is the Clutch Cycling Pressure Switch in the schematic below, and the LG/P wire goes back into the cab to the A/C controls and the BK/Y wire goes on to the compressor.

So, no "needle dust" came out? Yikes, that u-joint is G.O.N.E! New ones will fix a whole lot of problems.

Jake - Thanks for the offer. I did email you the VIN for Big Blue. As for the build sheets, I have it for BB but have not been able to fully understand it, as you can see on our page at Documentation/Specifications/Build Sheet Interpretation. And speaking of our pages, you are aware that we have three Electrical & Vacuum Troubleshooting Manuals (EVTM) on the site. Right? You can find them at Documentation/Electrical/EVTM and then the specific manual - 1981, 1985, & 1986. I have the EVTM's for the other years but just don't have them on the site - yet. In some ways the EVTM's are better than the fold-out sheets, which I also have some of, in that they break the individual "systems" up into one or two pages and disregard other things that might also connect. That makes them easier to follow, but at times it can be very confusing since you might not realize what else connects to that system. We also have the 1985 and 1986 fold-out diagrams on the site at Documentation/Electrical/Wiring Diagrams, but you really have to zoom in on them and that makes it really hard to follow. It isn't easy on the paper itself, but it is a lot easier than on a computer.

Nice truck. But I'm not sure I like the tires. They seem very large and aggressive. They might be ok on Big Blue, but on a 2wd F150 they seem way out of place and needlessly noisy. Plus, they'll have changed the effective gear ratio.

Sounds like a good plan. Yes, Yes, & Yes! The main install issue to avoid is a line that is, say, an inch too short. Thinking about how the line runs between the VALVE and the Rear Tank, and looking at the pictures where the line curves a lot at the VALVE 9189 Fuel Switch Unit, a thought I have is to connect the two lines to the VALVE 9189 (fuel switching unit} First, run both lines along the rail with installation under the clips along the way, then where they curve away from the rail to make the short couple-feet run to the Fuel Pump/Sender unit, match the old line alongside the pair from the last clip (markings will be visible on the old lines), then cut the new lines to the same length as the old, then install the Dorman fittings (making sure the new lines can curve the same as the old ones). Use the heat gun at this point for the Dorman installs as they would be in a better ventilated area and significantly distant from any fuel vapors. Both lines will be 3/8" as the Dorman L-angle connectors for the return line are 5/16 steel to 3/8 Nylon. The new 3/8-inch Nylon is 25-feet long so that should surely be enough for the Rear Tank parallel runs. I'll mark the return line with blue 3M tape to ensure it doesn't get mis-located at installation. Don't think I have any colored heat-shrink (might have some red somewhere). QUESTION: If the fuel selector on the dash is set to the rear tank, is all the return fuel SUPPOSED to go to the rear tank? The Mid-Tank (to be replaced once the Rear is up and running) has old fuel and shouldn't be cross-connected. Question #2: When the dash fuel selector is moved from one tank to the other, does the VALVE make any kind of click noise? Question #3: Can, or is it a good idea, to check the new fuel pump for operation before installation? I think you have a good plan. On the questions: QUESTION: If the fuel selector on the dash is set to the rear tank, is all the return fuel SUPPOSED to go to the rear tank? The Mid-Tank (to be replaced once the Rear is up and running) has old fuel and shouldn't be cross-connected. Yes, all of the return should go to the tank from which fuel is being supplied. Assuming the valve is working correctly. Question #2: When the dash fuel selector is moved from one tank to the other, does the VALVE make any kind of click noise? Your valve has a motor in it, as shown in the diagram below, and I think you should be able to feel or hear it move. But those valves are known to fail such that they'll pull from one tank and return to both. You might want to put some low-pressure air to it and see that it is switching properly. Question #3: Can, or is it a good idea, to check the new fuel pump for operation before installation? I've not done that as I don't want to spin the pump w/o some liquid in it for lubrication. But I didn't like the idea of having water in the pump, and I don't want to play with gasoline and electricity. So I didn't.

Probably should have asked the question before getting this far, but I have to say, I'm surprised. And this is even something that is carrying fuel under pressure! Clamped both lines to the porch this morning so they were able to bask in 85º sunlight most of the day. The tight rolls seemed to have mellowed out into a more-or-less straight line, straight enough for the run down the left frame channel at least. The yellow cardboard Dorman 5/16-inch line has the same indicator markings as the 3/8-inch line so hopefully, it is less likely to be counterfeit version. Good to read that I'm not alone on this. One thing I read yesterday was that Amazon is working on increasing their income from advertising. Their checkout pop-up-ads are everywhere. Unfortunately for the companies paying for their ads, they didn't make any money from me. Not only that, but my satisfaction with Amazon has plummeted. Update Aug 6: The third (and final) Amazon package arrived ... driver put it in our mailbox instead of on the front porch (like the first two) so didn't think to look there. Have all the pieces now. Tried to siphon the remaining fuel from the tank this afternoon and couldn't get the end of the hose into the fuel. Blew on the hose but couldn't hear or feel any sound of air bubbles. It is very difficult to get the siphon hose into the tank due to the small access hole that is nestled in the larger fill pipe. NEW QUESTIONS: (1) Should one apply some grease to the electrical connection for the Fuel Pump/Sender unit on the top of the tank when connecting the conductors to the new Pump/Sender? Due to the numerous contacts, some dielectric grease that might be good to use. (2) Edit: Should any grease be put on the steel stubs that the connectors attach to? (3) Pump/Sender gasket: Should anything be applied to the gasket surfaces, like, say a film of grease to allow the ring to tighten easier? Read an earlier post by someone that discovered theirs leaked so had to pull the tank again. (Not really excited about having the same experience.) I think I would use some dielectric grease on the connector. And I might put just a bit of grease on the o-ring on the tank as well as the fitting that the fuel connectors slide onto. And I'm glad you have all the parts now. Time to make a fuel system! And remember, Nylon doesn't stretch very well.

Thanks, Bill. That's interesting as Huck, the 1990 half-truck, didn't have that switch nor is there a place for it. The A/C seems to work fine w/o it, so I guess I'll continue to use it this way.

I hope you are right. And this gives us an excuse to take BB out.

Thanks, David. However, I'm a bit concerned with how dark it is. He said he used "5% ceramic tint", which I think means it only passes 5% of the light. He says it will clear up more as it cures, but I'm a bit worried that it is too dark to let us see the mountains. Janey and I need to drive the truck and see what we think as I may want him to put a lighter tint on.

Interesting that you don't have slide locks on a truck built in Nov of '79. Supposedly they didn't phase out the slide locks until of March of '81, and even then several plants continued to install them. So I wonder if yours have been changed out. As for Big Blue, the factory aux battery sits on driver's side where the coolant recovery reservoir usually goes. I've included two pics below, the first showing BB now with the EFI, and the other showing it as it was with the carb. The aux battery supports both the winch as well as the 3KW inverter - which powers the air compressor, among other things. It is charged by the 130A 3G alternator, and the two batteries are paralleled via a 200A Cole Hersee Smart Battery Isolator. Those isolators close when either battery voltage is above 13.2V for 2 minutes. And the batteries are isolated when both battery voltages are below 12.7V for 1 minute. But I can force parallel for one minute with a switch in Mission Control.

Wow! You did do a thorough job - both with hanging the doors as well as writing up the process. As for how hard it is to close the doors, crack a window open and see what difference that makes. The new weatherstripping has been on Big Blue for probably three years now and it still takes a significant push to get the second door shut - unless you have a window open. The cab is that tight and the air is getting compressed.

Larry - Can you post a pic of the high-side switch? I have an FS10 system from a 1990 F250 in Big Blue and it doesn't appear to have that switch in it. Or maybe I'm missing it?