So I noticed that my FASS pump wasn't running yesterday, but I don't really drive it so I figured I'd mess with it this coming weekend. I had an extended crank yesterday when I took it for a drive but it ran fine. I figured that the FASS will pass through fuel so I could drive it a little bit. I was going to drive it to work today to mess with the pump not running and the truck died on me as I pulled out of my driveway. I was able to get it manually started by priming the system up front and drove and picked up my car and took it to work. My questions are 1. Do you guys think the FASS not running is what killed the truck? Does it not pass enough fuel to run? And 2. Does anyone have any idea why my FASS would randomly stop working? I've only had it a year and have already replaced the filter/separator once with CAT filters. Could the separator being full of water make it not run? I haven't drained it yet this year. I don't really drive the truck, maybe one or two weekends a month and to the drag strip every now and then. Any help would be appreciated. -Garrett
Truck Dies
- Thread starter gl4787
- Start date
1- I'm not overly familiar with the FASS pumps, and if they are flow thru or not, but there is a strong possibility it would be what killed the truck
2-If the FASS quit running completely then its probably something electrical. Never heard of a pump quitting based on water in the water separator. Does it have a fuse or a relay? check those
2-If the FASS quit running completely then its probably something electrical. Never heard of a pump quitting based on water in the water separator. Does it have a fuse or a relay? check those
The FASS is supposedly a flow-through design, so it would not cause the truck to die. And I agree, an electrical problem is the most likely reason the pump is not running.
A completely full water separator could cause some problems, so I'd check/drain that ASAP.
As to why the truck died once the FASS quit, it could simply be a leaking factory filter head. Your truck is 12 years old (just like mine), and I had my filter head fail years ago. The lift pump masks the failure, because it prevents air from leaking in. But once it is off, the air can get in and break the suction. You might need to rebuild the filter head, or do what I did and completely remove it.
A completely full water separator could cause some problems, so I'd check/drain that ASAP.
As to why the truck died once the FASS quit, it could simply be a leaking factory filter head. Your truck is 12 years old (just like mine), and I had my filter head fail years ago. The lift pump masks the failure, because it prevents air from leaking in. But once it is off, the air can get in and break the suction. You might need to rebuild the filter head, or do what I did and completely remove it.
My old fass will flow enough for small mm3, soon as you give it throttle you can feel it starving.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
I had actually given some thought to removing the factory filter head. I hadn't even thought of that being the leak, It has been off the truck quite a few times, it wouldn't surprise me. Thanks
Didn't really spend much time trying to diagnose it yet, but did check the fuse and it looked okay to the naked eye, but who knows. Thanks.
Another thing I forgot to mention is that the truck has been a little lopey at idle lately. I can watch the rail pressure gauge bounce off 5k lbs. and back until I accelerate from the stop. I kinda figured it was the FPR so I was planning on ordering one in the next few weeks. Not sure if it's related or not, just figured I'd mention it.