Runs awesome. but almost 2 weeks ago I went tout start and it did but idles awful am for 5 or so seconds and diedon't. Wouldn't start after that. I let it sniff some fumes of starting fluid. I didn't spray right into the intake. I just sprayed the very outside and the fumes traveled in . it started and then not 1 issue. been fine ever since . but last night it did it again. since it started with the spray that tells me it wasn't getting fuel. maybe lift pump letting go? I think it's strange cuz it runs good wen it's goin and it only has done this 2 times in 2 weeks.

 

It's only done it after sitting overnight?

Effectively, what's happening is you have a leak that is allowing air to get into the supply side of the system and allow it to drain back to the tank.

First, check the fuel filter. Make sure it's not just leaking out the bottom.

I'm guessing you haven't deleted the return line from the fuel filter yet? If the fuel filter isn't leaking, that's the next place to check - there is a little check valve in that return line coming off the fuel filter, which is probably disintegrated by now which is supposed to prevent this from happening.
There's a ford TSB to just remove the whole line, plug it.

Also, the check valves in the lift pump may be going; unless you replaced it recently, it might be a good "preventative measure" replacement - they are only about $25.

If you still have problems after all of that, you can get a check valve(I like the squeeze-bulb primer bulbs for this) and install it before the fuel filter, after the lift pump. You have to cut the hard line between them(tubing cutter), and just splice it in with a bit of rubber fuel line and hose clamps. Remember, it's only 5-7 PSI at that spot.

 

it does not do it overnight . both times it did it was only a few hours. I have not done the return lines tsb. did not know there was one. what is the effect besides the check valve not being used by doing this? I'm guessing it uses more fuel? I kno in the 7.3 engine to much fuel causes higher EGT temp like other engines but I kno I can not run more than like 1000 degrees under a load or piston melt will happen. that's what I found in previous research. I'm ok with doing the tsb but just want to be sure I'm going to be safe from higher dangerous EGT temps. I do kno the adjustment screw in the ip is turned up. I don't kno how much the previous owner did it. when I take off and let off the clutch is has a tiny puff of black out the exhaust and under heave acceleration or up steep hill it does smoke but barely. not like all the other modified diesels running around.

 

OK, so lets get back to basics here:
Deleting the return line from the /fuel filter/ simply reduces the capacity of the system to remove air that might get trapped. That's it's only purpose.
Air will be bled out in smaller amounts through the IP itself, and out it's return line.

As far as the whole 'use more fuel' and EGTs... I suggest you read up on how the IP actually works here.
Fuel usage is determined by:
1. Throttle position
2. RPM

It is /limited/(i.e. absolute maximum) by the fuel screw. All this fuel screw does is change the maximum amount of fuel injected per cycle. However, this only affects it when you are giving it enough throttle(and therefor fuel) to hit the limit.

This is why you can run a massively turned up injection pump on a NA engine if you have to... you just can't floor it. At part throttle, it will inject fuel in accordance with the throttle position and RPM.

Also, same with EGTs. EGTs are directly related to how much fuel is being burned. More fuel = higher temperatures. While you really do want a meter to tell you how things are doing, you should be able to go by a 'rule of thumb': If you are smoking out the exhaust, the EGTs are too high.
I've found that if I'm burning the fuel cleanly(no smoke), the EGTs stay down in the safe range. It's only when running rich(too much fuel = smoke) that the EGTs start climbing dangerously.
Also, you can run "too high" EGTs for a minute or so without much risk, it's when the heat soaks into the metal that it becomes a problem.

Also, you have to worry more when hauling a trailer - unloaded, you'll have a really hard time making your EGTs high enough for long enough to do damage, as long as you keep an eye on your smoke.

Edit:

You Tube

Really good explanation of the IP and how it works.

 

thanks for the info. I think I'm going to do the return delete on the filter. do you gave a link that explains that or is it as simple as take the line off and cap it on filter housing and then what do I do with the line I take off? and as for the lift pump I guess if it does it again Ill have to find a way to see if that's pulling fuel while it's not starting. or just replace it considering its cheap to buy. what about the valve on the frame? the one that is for the tank selector? I think I read soemthing saying that's a common problem spot. how would I know if that is giving me an issue if it's not leaking?

 

Just cap/plug it on both ends.

One test is that you can disconnect the output line from the fuel filter and run it into a container. I believe you should get about 1/2 pint of fuel in 5-ish seconds of cranking?
If not, well, you'll want to work backwards - filter, lift pump etc.

You can also grab a gas can filled with diesel, and a length of fuel line(5/16") and just remove the input hose off the lift pump(it's the side with the hose barb). Run your length of hose from there into the can of diesel, bleed the air out, and then you can test things. That will eliminate any fuel selector valve, tank, pickup and line issues.