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I ran my truck out of fuel yesterday on my way to work. I know how stupid this is but I thought I had enough to make it and I didn't have time to stop. I've tried since yesterday evening to get this thing started back but it just won't do it. I can get fuel to the VP and prime the FASS but as soon as I tighten the nut back up on the VP and try to start the truck, I lose prime with the FASS. Also, I am getting fuel at the injectors but still no fire because I lose prime to fast. I even tried leaving the but on the VP loose while I cranked and still no fire. I have been having problems that I thought might been VP related but want sure. Could it be that the VP is done for??? Please help!!!

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I can't recall the fass prime procedure 100%, but if you look it up on their site you should find what filter to loosen. My fass didn't prime until I cracked a filter.

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  • Staff

I had this problem once when priming would not hold. I kept getting drain back to the tank because I failed to properly tighten down the factory filter cap to the required 25 foot pounds. It would allow drain back by letting air go in under the filter cap.

Sometimes guys discovered a cracked filter cap because they used the center square drive instead of the large socket to loosen or tighten it down. So check the filter cap for cracks and proper gasket alighnment.

Also, I've only had to use a 3/4 inch open end wrench to loosen a couple injectors. Never had to prime at the VP. Ever.

You can also bump the starter, which gets the lift pump running for 25 seconds and look inside the factory filter, with the cap off and see if the lift pump is filling up the filter housing. You will get drain back with the cap off but can see if the lift pump is doing it's job.

I generally fill the filter housing the new filter cartridge. Tighten down the cap, not having to work too fast. Bump the starter 2 or 3 times with a couple injectors loosened till I see fuel weeping at the injectors. Bump one more time and then start till she runs rough. Then go tighten the two loose injectors while she is running rough and then she smooths out and runs like normal.

Tank drainback can happen so rapid when you have an air leak that it is frustrating to try and start it.And You will never get the whole system primed by cracking fittings near the VP, you have to crack two injectors at the end of the system to get full prime. Tank drain back can happen too, when there isn't enough fuel in the tank. Once I had enough fuel to prime the system but soon as I got in to start it it would drain back because the tank was just borderline to the bottom of the drawstraw. In this situation I found my drawstraw was cut a bit short and have since fixed that.

I want everyone to know, if you've read this far, that Racor filters makes a filter with a hand priming pump on it. I have one on my first gen and it works so fast and you can pump it hard to check for leaks and weeps in the system.

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I had this when I installed airdog, loosen the closest filter get someone to bump starter fuel will push air out and fuel everywhere. Then do same to the next filter, its going to make a heck of a mess but hey it got the job done. Go to injectors back off three of them and bump starter several times. Close two lines bump again, then crank, it should start hitting and then start.

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I know this is no help now...  I normally refill fuel at the half way mark.  On a trip, I start looking for fuel them but will run to the last quarter.  

I had the dread LP failure which was when I got the 150AD installed which included getting the system bled & started.   

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  • Owner

I've seen rare cases where lift pump don't prime again. So I typically loosen the fuel fitting at the VP44 and using airgun and rag blow air pressure into the tank till the fuel flows at the VP44. You'll need two people to do this. So while the fuel is flowing have a second person close the fitting and you should be able to start the truck again.

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