crank no start

[Diablos]

2007 dyna lowrider, stage 2 w/se255 cams, fueling oil pump/cam plate and powervision tuned (fuel moto).

i previously had a crank no start issue that turned out to be the fuel system (pick up sock was disintegrated, fuel filter was full, etc), i ended up replacing everything except for the pump and lines (as they seemed good). 

heres the issue

im in sturgis today and go to leave, fire it up and it backfires through the intake and dies. Crank again (takes a few times to catch), and have to goose the throttle to keep it running, but once i let off the throttle it settles in and seems ok, so i pull out onto main drag. Dont even make it to the next stop and its spitting and sputtering, and then fully dies. Cranks but wont restart. I think i can hear the fuel pump (but im in the middle of sturgis...), but no restart and i dont want to kill the battery by continuing to crank it. Get it towed home, hook up my fuel pressure gauge to conduct a fuel pressure test and it fires up fine, just like nothing had happened at all.  for just a moment i may have seen 40psi (might have been a total anomaly, or bad eyesight), but ive tested it a few times since and only seen 60psi with it bleeding down to 55, it holds 60psi while sitting there idling.

im kinda at a loss and dont want to be stuck on the side of the road.  can a pump be bad only under load?  am i zeroing in on the wrong thing and perhaps its something else like the kill switch?  im all ears

[Ohio HD]

That sounds like a devil of a problem....

Since the lines are probably hard as they're 15 years old, I'd start there and replace them. Look for bubbles in the tank when the ignition is turned to the on position,

[Diablos]

any good way to test these delphi coils (4wire) without a breakout box?  

[JohnCA58]

Could also be a crank position sensor going out, If you have a tach, watch the tach needle and it should be bouncing while cranking to start.

[Diablos]

when it wouldnt start up in sturgis i did check the tach and it was moving, and iirc i put a new crank sensor on it when it turned out to be the fuel system this past november.

[IronButt70]

Long shot but check the o-ring on the quick disconnect. Buddy had similar issue. New o-ring fixed it.

[Diablos]

Long shot but check the o-ring on the quick disconnect. Buddy had similar issue. New o-ring fixed it.

i'll take any suggestion 

[Coyote]

The oring may cause a leak but I don't think it will prevent fuel flow. The quick disconnect does have a history of wear in the grooves that prevents fuel flow. Pushing it in and rotating the locking ring will sometimes fix it.

[Diablos]

The oring may cause a leak but I don't think it will prevent fuel flow. The quick disconnect does have a history of wear in the grooves that prevents fuel flow. Pushing it in and rotating the locking ring will sometimes fix it.

looked through the paperwork previous owner gave me (not much as the bike only had 3k miles on it), and looks like he had that line replaced.  dont know why, leaking?  that does seem to be common from my searching

[Coyote]

The problem is that if you disconnect the fitting, you really need to lightly lube it before re connecting. If you don't the rubber oring is dry and it can catch and end up damaged and leaking.

But there's also a wear issue with the groove the balls seat into.

I think at this point you need to go back to basics. Check for spark. Check for fuel pressure and flow.

[Diablos]

fitting is lubed each time with fuel tool lubricant.  fuel tool pressure gauge used to verify pressure is within specs per harley manual (55-60 psi the entire time)

definitely has spark, it did as soon as it rolled off the tow truck.  fired right up as soon as i had the fuel pressure gauge on it to start testing.  

crank senor replaces in nov along with plugs and wires

so possibly coil is on the way out?

[Ironpig9]

Could it possibly be you got some gas with water in it in Sturgis? I know I got some bad gas on a trip out west and after battling thru most of a tank a refill solved the problem.

[Diablos]

Could it possibly be you got some gas with water in it in Sturgis? I know I got some bad gas on a trip out west and after battling thru most of a tank a refill solved the problem.

i filled up at sams club before we headed up to sturgis that day, and although ive never gotten bad gas from them, its a possibility. 

[Diablos]

is the correct way to test these 4 wire delphi coils to test ohms from prong "b" to the plug wire post?

the electrical manual states how to test primary side (test from a to c, and from a to d) but has nothing on the secondary that i can find

[Diablos]

New coil, test road it for 20ish miles and had no issues.  Fuel pressure was 60psi the entire time, and i got on it good.  Not as hot out as the day it died on me, but the bike was up to full temp,  no hesitation or misfiring.

Only thing that bothers me is not being able to fully test the old one.