Help needed for hard Starting

[scjarena]

History, 1990 F350, 7.3. Bought as project truck. Was horribly maintained by previous owner. Had fuel leaks everywhere, replaced return line injector o-rings, fixed filter housing, using one piece fuel filter. New lift pump. Not a drop of fuel now. Problem, I’m having is seems like pump is losing its prime. Once started it runs good until next morning, it is extremely hard to start. I was thinking, its sucking in air between tank and pump so I temporarily run one fuel line hose directly from one tank to the pump. It runs good, but next day I’m back to hard starting. BTW, it has a new starter, two very good batteries, it does turn over fast during starting. Do you think I have a problem with my injector pump? Could lift pump be sucking in air? Any help would be appreciated.

 

[snicklas]

Do you have smoke while cranking? How long do you have to crank before it starts?

To me it sounds like a glow plug issue, not air intrusion.

 

[square1]

Had to replace the injector line olives to get mine completely sealed up. No fuel leaks, but was still letting air in when shut down. Park it with the nose downhill and see if it starts easier all other things being equal.

 

[franklin2]

I agree, you need to determine if it's a glowplug system problem or a fuel/air intrusion problem.

If you have a glowplug system problem, it will just crank crank crank, and there will be lots of white smelly smoke leaving the tailpipe.

If it's air intrusion, you cycle the plugs as normal, and it will usually start right up, but then it only runs about 5 seconds and then it quits. With air intrusion, it will run on the fuel in the injection lines right away till that runs out. Then you have to crank and crank to pull new fuel up into the injection pump.

 

[scjarena]

How long to start? Not sure. I crank for a few seconds, let starter cool, repeat. Maybe 4-8 times and it will start. I think its fuel related, because I don't see hardly any smoke while cranking. I just installed new set of motorcraft glow plugs. The wait to start light will shine for maybe about 8-10 seconds and then go out, so I think GP relay is working ok. I need to check the injector line olives. Interesting about parking it downhill, I'll try that next.

 

[IDIoit]

I would also plug it in and see if that helps your hard start.

 

[scjarena]

"Plug it" ,??

 

[IDIoit]

"Plug it" ,??

the block heater. plug it in. it warms up the block and helps cold starts

 

[scjarena]

I happened to have a AN hose with ends and fittings and I replaced the line with the olives from filter to the injector pump. I then put a clear piece of line between the lift pump and filter. While running, fuel flowing in was bubble free. Shut off engine for a couple hours, went back to check, still no air at clear line. Checked in the morning, and it was partially full with air. So, I’m thinking there is air seeping in either in the filter housing, or the injector pump, while the truck is sitting. Thoughts?

 

[SebastIDIan]

Checkvalve before fuel filter cured my hardstarting problems. Even with leaky returns it fires right up.
How long does the "wait to start" light stays on for? How often does it "click" under the hood after it does?

 

[franklin2]

There is a little elbow fitting on top of the filter housing, that is your fuel heater. Is it damp around it with fuel? It has a o-ring under it that can leak when it gets old. That was my last air intrusion culprit.

 

[nostrokes]

Also check your oil and see if there is fuel in it. Lift pump maybe leaking and draining your fuel line into the oil. Pretty common problem with the mechanical pump it seems.

I would also try the plugging it in and seeing if keeping the block warm helps though I know it doesn't get extremely cold, at least to us northerners, in Houston...

 

[scjarena]

I think I having problems with the glowplug relay. When I turn the key on, WTS light is on for 10 seconds then goes out. No clicking. To check glowplug operation, I take one out, plug in one side and hold to ground while I had someone turn the key on. I didn't see the glowplug heat up.

 

[franklin2]

Get a testlight and probe the large relay connections to see if it's passing power, or if it has power at all. There are some connections in the harness that like to burn up that feed the relay power. Just make sure you get someone to glow the plugs and put a load on the system when checking with either a testlight or a meter. This circuit is just like the starter circuit, a bad connection can pass enough power to show a reading on the testlight or voltmeter, but when the going gets tough when the glowplugs are pulling all that current, the bad connection gives out and the voltage drops.

 

[scjarena]

I pulled the controller and relay and noticed the wax sealer stuff was deteriorated or melted off of the controller. I'm get going to get a new controller. Any recommendations for type or brand? Thanks