Tips on initial starting after fuel system work

[coolwind57]

The last two times I did significant work on my fuel delivery system, I had problems getting my truck to fire back up promptly.  The first time was when I removed my bed and replaced my fuel tank and filter.  The second time was when I upgraded to 746 injectors.  I am now getting my truck back together after stripping engine down to do freeze plug replacement.  With that, I've once again had to disconnect my fuel delivery system.

 

Those last two times took me nearly an hour of cranking and trying to feather my pedal to get the engine to fire up.  Both times it would sound like it really wanted to fire at times but would peter out until it finally reluctantly started and ran.  I had to put a battery charger on throughout the hour-long process to keep it up to charge.

 

I had just recently learned of pulling the fuel pump relay prior to commending work.  Unfortunately, I forgot to do it this last time if that makes any difference.

 

So are there any guidelines on performing an initial startup after fuel delivery system work?  Does everyone experience this near hour-long process?  

 

 

[gogmorgo]

The biggest issue is getting fuel pressure up to the rail. Turning the key on and off will run the pump for a couple seconds each time but if the fuel lines are drained it may take quite a few key turns before it has adequate pressure at the rail. Cranking and using the throttle doesn't really help with a fuel rail full of air either. 

My suggestion if you're having trouble would be to pull the fuel pump relay and jump it so the fuel pump runs for a few minutes, and maybe purge some of the air out of the rail. You could also use the Schroeder valve on the rail to try to bleed some air out. Using the purge button on a fuel pressure gauge with the bleed line in a container would be safer than just pushing the valve and risking spraying fuel all over the engine bay. 

[HOrnbrod]

https://comancheclub.com/topic/54323-fuel-system-leakdown-test-fail-and-fix/?tab=comments#comment-554382

[Ωhm]

Disconnect and plug vacuum line to fuel pressure regulator. This will maintain maximum fuel pump pressure during crank.

[coolwind57]

6 hours ago, HOrnbrod said:

https://comancheclub.com/topic/54323-fuel-system-leakdown-test-fail-and-fix/?tab=comments#comment-554382

 

Check valve seems like a good idea.  I'll play with that idea when the time comes.  I'm not sure I have the problem yet.  I've put all new o-rings on my injectors, so we'll see what's going on with pressure once I get this thing running.  I also love your shrader valve-mounted pressure gauge.  That's on my to-do list too.

 

 

I'll try the other tricks as well.  Thank you guys for your input.

 

[cruiser54]

Just cycle the key a few times and go for it. 

[coolwind57]

1 hour ago, cruiser54 said:

Just cycle the key a few times and go for it. 

 I did and she fired up within 5-6 seconds this time.  Success!  The last two times however, this cycling of the key didn't help much.  I'm also happy that I have no fuel leaks,  i had carefully prelubed the fuel rail disconnect O-rings using a Q-tip and petroleum jelly.  I also used all new O-rings for my 746 injectors. 

 

Engine came to life, but my I've got hard ticking noise coming from bell housing.  I chose not to run the engine but only a 30-40 seconds because of this.  I'm thinking that I still didn't get that dang torque converted seated correctly...or I had damaged something already.  Another weekend of pulling an transmission, it seems.   Praying now that I didn't destroy it.