Apparently I picked up a bad tank of fuel. Anyhow, I'm now north of Santa Fe and just installed my last set of filters and am no longer laying down a concealing black smoke screen in all this pristine air up here. After changing these filters, which I might add is a major PITA due to location and the fact that no matter how carefully I do it, bleed and pump, prefill etc., fuel drains back from injector pump and major cranking and cracking of injectors is necessary to get her restarted, I'm wondering about installing an aftermarket filtration setup.
Davco looks appealing with its simple monitoring, easy filter change, and inexpensive filters in a variety of micron sizes. I "think" the primary Racor filter on my unit is a 30 micron, have been unable to find out what the secondary filter is. I'd like to install a large single, 2 micron filter, and be done with it. Anyone know if this would work with a suction filtration system?
Chuck
Chuck,
As for the hard starting, fuel draining back on a Cummins, you for sure have a air leak, allowing air to replace the fuel, as the fuel drains back to tank. Next time the starting is hard again as it has to pump the fuel back up. This is a common issue with many emergency generators as fuel lines age, deteriorated hose, clamps get loose etc.. For me, I would go over the fuel system checking for loose hose clamps, bad rubber fuel line, loose filters etc. A very small air leak will make starting very difficult.
A simple test would be to restart the engine after having it running good. If it restarts good, but is hard to restart after a few hours or over night, it is a clear sign of fuel running back due to air leak in system.
Good luck.
Dave,
She busts off good, quick starts no matter how long she sits. It's just when I swap filters. Problem is when I remove the filters, fuel drains back from engine introducing air into system. I've tried to purge it using the little thumb pump plunger. I've tried pumping it up before removing filters. If I crack the Racor drain, fuel doesn't run out, it sucks air in. It's like there's a vacuum after the filters. This is a new one on me.
Chuck
Chuck, My 8.3 has a ball valve just prior to the RACOR, by shutting this off I can change the RACOR without losing prime.
I also have had a PRIME LOC remote filter installed ( no longer available ), so that Filter is adjacent to RACOR. Someone else probably makes a remote filter set up.
I would look hard for an air leak, not normal to lose prime.
Gary B
Yes Indeed, I misread your first, I went off thinking you lost prime as it sat. So whole new story.
Gary is right, having a ball valve or good check valve B4 the Racor is good idea. Openi9ng the bottom of the Racor and pumping, Dont think you are getting anywhere except for exercise., I would only open a vent on top of the filter on the Cummins engine and then pump fuel until the filter is full and you get fuel out of the vent. Close vent and start engine. NOw if you run engine out of fuel, you might have to bleed a few injectors to get rid of the rest of the air. Fuel pumps do not pump air real good, not enough to get fuel into a unbled injector.
Cheers
Chuck, My procedure for changing filters :
Close ball valve ahead of fuel filters.
Remove Racor filer, after replacing clear bowl and O Ring, fill with fuel;.
Open ball valve and start engine til it runs smooth.
Close ball valve
Remove secondary filter.
Fill with fuel and screw back on.
Open ball valve
Start engine.
I have been doing this for a long time and have not lost prime.
Gary B
Gary and Dave,
Ah, a ball valve. Don't have one but will soon. Thanks for the help, looks like there are filters in Taos so headed that way.
Chuck