Ford Powerstroke Diesel Forum banner

Please Help!!!! 7.3 starts only with small shot of ether

43K views 11 replies 5 participants last post by  CloverLeafFarm  
#1 ·
My truck cranks over really fast but will not even try to start unless i shoot a small shot of ether into the intake. Once it starts it runs perfect. I can drive it all day but if I shut it off it wont start again unless I give it another small shot of ether. It only takes a 0.5 second of a spraying.
 
#2 ·
You're playing Russian Roulette you know....

Glow Plugs & Either are a time bomb, if you're going to continue this you should disconnect the Relay before you do some real damage.

BUT,,, here's what's most likely going on. You have a problem in building HiPres oil for the injection system. Your computer needs to see around 500psi before it will trigger the IDM to fire the injectors. Cranking on the starter alone it builds below that threshold but with the either it can now meet that pressure because of the extra RPM.

You now need to monitor your sensors with the right scanner to know what's going on. At one time this was an expensive thing to get (we are not, specifically, OBD-II so regular scanners don't work for us) but today it's as simple and inexpensive as an "App" to get lots of useful info -> http://www.powerstroke.org/forum/99...forum/99-03-7-3l-general-discussion/1044057-ford-superduty-diagnosis-cheap.html

One thing you can try would be to unplug the ICP sensor to bypass a low pressure reading and see if it starts then without either. Be aware though that doing this will set a code and when you get it scanned expect it to be there.
 
#4 ·
Awful hard to read your screenshot (yea, you don't need an App ;))

How long is Long? Slow to build pressure can be many things, leaks that bleed-off good pressure the pump is making (O-rings, stuck IPR, that kind of thing), the HPOP could be tired, the HPOP reservoir could be emptying as it sits because of a stuck checkvalve (check the level before you start by "dipping" the long end of the Allen wrench you remove the plug with), ICP giving bad info (unplugging would have fixed that though).

It can be tricky to diagnose with so many possibilities, start with the easy stuff ;

 
#5 ·
Well the slow hard starts started about a month ago. That's when I took the screen shot of auto enginuity. The graph was just showing that the truck would start after 45 seconds of cranking. It never got any worse until 2 days ago. Now it doesn't matter how long you try to crank it, it will not even try to start. The ICP made no difference and hpop reservoir is completely full.

I pop the hood pull out my air filter replacement sensor and shoot a small shot of ether in the intake hose. Shut the hood and crank the truck. It takes about 5 seconds for ether to make it to cylinders then it fires right up. We have been driving the truck all weekend and runs great after I get it running. I have had to do the ether shot about 30 times total this weekend. But we have put about 300 miles on the truck. Other then starting I trust it to drive across country.
 
#6 ·
AGAIN,,,, the PCM needs to see that 500 but, once started, it can drop below that and run OK. If what that graph says, and I couldn't believe I was seeing a 45sec crank time (kinda hard on the starter to do that), it sits at "0" for all that time then you have a real problem!

And AGAIN, you should disconnect the GPR or Stop using either (GPR is an easy thing to shut down, just take either sm wire off it and insulate it).

If the HPOP res is full and disconnecting the ICP doesn't help, I would next want to know what the PCM is commanding the IPR to do as a percentage, I assume it's maxed-out. Maybe check out the coil & connections then pull and disassemble the IPR would be next.

 
#8 · (Edited)
Well i moved from Tuscaloosa AL back to Panama City, FL two weeks ago and since the move i haven't had to use ether. It starts every morning great for the first crank of the day, but after that it varies. If you shut the truck off and try to start before waiting 30 minutes I have to use ether. Usually when we go eat somewhere it sits for about an hour. It starts in about 15 seconds after sitting for 1 hour.

I took the valve covers off this morning hoping to see that the top injector o rings were shot and oil would be shooting everywhere like the YouTube videos i have been watching. But they all seem to look fine. I also swapped another IPR that i know was good but it didn't seem to make a difference.

I tried to upload a picture but i guess i haven't posted enough to add pictures. I did a live data graph and 2 seconds into cranking the duty cycle starts to increase. Duty Cycle 35% ICP 250 psi, Duty Cycle 40% ICP 500 psi, Duty Cycle steadily increases until it reaches 65%. It stays at 65% for 7 seconds, while its at 65% the ICP slowly increases for 7 seconds until it gets to 1000 psi. When it finally gets there it begins to start then everything levels out at idle Duty Cycle 12% ICP 600 psi.
 
#9 ·
Well quick update. I just went back out and examined the injectors closer while engine was idling and i noticed the number 2 injector seem to have a bit more oil around it. Shut truck off and got my dad to start it and it looked like someone was holding there thumb over the end of a water hose. Sprayed everywhere. After it started up it just poured so i pulled the injector and both top orings had a huge chunk missing. So tomorrow im going to go ahead and replace all the orings. Will let you know how it runs.

Where do yall recommend buying injector o rings from?