My truck is hard to start after sitting even for a short time.  I have replaced the washers on the banjo fitting back of the head, the seals on the T fitting, and the fuel line to the tank.

I just pressurized the tank with air there are no leaks I can find anywhere.  It has new injectors and new crossover tube O rings.still has the same problem.   No fuel in the oil.  Any suggestions from the experts?

 I experiencing the same thing myself. My suspicion on mine is the AD quick disconnects might finally be causing me problems. I am not sure FASS uses them though. My problem is intermitant however. One time it fires off fine the next time a hard start. Might sit for 15 minutes and hard start or sit all night and bust right. I also have no vsible fuel leaks, but air is getting in there somewhere. I have not had time to dig into mine as of yet.

 If you have quick disconnects they might be suspect.

I had my factory fuel filter cap not seated correctly and kept getting fuel drainback to the tank letting air into the system. This only a guess though.

 

After shut down you have to feel around each fuel connection for anything even slightly wet. Mine was a new 1/2 inch line connection to the inj. pump had a small imperfection on my second truck and I just emery clothed it and put it back in. No more leaks thanks to Dripley on teaching me that one. 

 

When you pressurize the tank does it fire right off? Faulty tank vent?

Edited November 2, 20186 yr by JAG1

Do you park your truck on flat ground, facing uphill, downhill? I had a similar problem only when I parked facing uphill.  It also manifested on a very slight incline (1-3 degrees maybe) of the driveway. I'd face downhill overnight, no starting problems.  Flat ground, intermittent problem. 

 

Subsequent events led me to never identifying the problem, but somehow fixing it in the process, as it went away: I dropped my fuel tank to replace the feed lines to the AD and IP, and when dropping the fuel tank I kinked the hard plastic return (from engine) fuel line.  It did not kink all the way, but maybe reduced the flow area by 1/2, so I thought it would work out.  I buttoned it back up and ran the truck, and had fuel in the oil shortly after.  Lots of fuel.... Measured an extra gallon of lube 'solution' after 3 days of driving. Figured the return line was restricted enough to pop the o-rings on the injector bodies and pump fuel to the oil.  I pulled the valve cover and watched 4 of the 6 injectors leaking fuel to the top of the head.  Needless to say, replaced all the injector body o-rings and never had an issue since. I also replaced the kinked return tube with some nicely routed rubber hose  

 

How long have you been running like this?  Long enough to find fuel in the oil, even with a minor leak? 

 

Have you pressure checked your fuel overflow valve for proper operation? If it's low on opening pressure, it can cause fuel drain when it shouldn't, contributing to a hard start.  

I just checked the fuel cap.  I clamped the fuel line between my pre filter and the fuel tank, let it sit with nose up hill.  Went back later and it fires right up.   I will pull the bed off again if it ever stops raining.  Will update on the outcome.   Thanks everyone.

Air gets in the system from up front, acts like a vent to let the fuel drain back and fills with air making it hard to start. Instead of raising the bed right off you should check for air leaks on all fuel lines that are higher than the level of the fuel in the tank. Which are mostly up front in the engine bay. Run your fingers around the vp connection and all other connection areas for anything wet. Best to check after a run when fuel pressure can reveal those areas of a leak. Like said before though, the fastest drainback/ loss of prime was when my fuel filter cap was not torqued to the 25 ft lbs. required.

 

Hope you find it. BTW, I got rid of my quick connects as well.

Edited November 3, 20186 yr by JAG1

Not to say @JAG1 is wrong...

 

Like on my truck I've got a visible trail of fuel from about #5 or #4 injector line all the way off the back of the engine and dripping on the ground. What I need to do is shoot the area with brake clean while its hot and get it good and dry and do a quick WOT run and check again looking for which one is leaking fuel. In my case, this is not causing a hard start at all but the fuel trail is present and visible. Just got to isolate the source and fix the leak. 

Not like your wrong... JAG1 it that there is many different cases where fuel leaks will or will not cause hard starting like mine is a case of it not creating hard starts but I create a visible drip spot on the ground.

I know Mike, my leak at the VP connection usually caused no hard start except once in a while. Usually only after sitting all weekend and even then was only longer cranking time is all.

Has your fuel module been modified?

Yes I have a drawstraw for around 10 years nowadays

Did you do anything to the straw for the return from the head/injectors into the basket? Or is it an old school straw only, independent from the module?

I can't answer that for sure.  Been a long time since I did this, I do remember modified the basket I had too drill holes in the side wall my output and return both hook to the drawstraw.

My straw is NOT in the basket. I don't want to draw in that hot fuel. I get cooled fuel from the tank.

Sounds like it is set up right the way Vulcan performance Parts has instruction to that effect. I do like it when the screens get removed off the module though.

 

If there is any problem at the module it may be the connections at the top.

 

 

I’d suggest parking nose up hill overnight with a full tank of gas and seeing if the problem still persists.

@notlimah Probably won’t start with gas. Try some diesel ??

You need to point the nose downhill and see what happens. Get the fuel tank higher than the engine. Mine is doing on and off in any position. Mostly been parking level where am at these days. 

May be off topic a bit, but Fass doesn't place an inlet screen on their lift pumps do they? Just like the two Raptor 150's I got over a year ago, I had to pull out those screens you can see down in the inlet side of the lift pump.

Edited November 4, 20186 yr by JAG1

17 hours ago, Royal Squire said:

@notlimah Probably won’t start with gas. Try some diesel ??

 

He/you know what I meant! 

 

5 hours ago, JAG1 said:

May be off topic a bit, but Fass doesn't place an inlet screen on their lift pumps do they? Just like the two Raptor 150's I got over a year ago, I had to pull out those screens you can see down in the inlet side of the lift pump.

 

It’s been a while since I installed mine but I don’t think they do have screens.

I parked facing down hill, it starts instantly.  If I remove the fuel lines at the tank how much pressure would I be safe with applying to the lines back to the engine?