Fuel Filter trouble

[babrom]

Hi everybody, first time posting on forum. thanks for all the good advice. I install a Mega filter from JK about 4 Months ago and have not had a problem until about 2 or 3 weeks ago. The truck will stalls shortly after start-up. I'll pump the OEM filter and bleed. Small amount of air comes out. after that the truck starts fine. runs good until I shut it off. but this only happens once every 3 to 4 days. but lately it has did it once a day. Tank level did not make a differents. I have the filter Pre-OEM .I have checked for suction leaks but everything looks good. Is there a easy way to pressure test the system to see if it has a leak? I tried changing both filters to double check the seals. no luck. Does anyone have any advice? Thanks for your help

[ADub]

My truck started doing that yesterday and its bone stock

[DmaxMaverick]

Babrom

Change your fuel filter(s).

Fouled filters create higher suction in the system, which causes out gassing of the fuel. The Mega has an air trap that allows a lot of air before it actually passes it. Once the pump gets a slug of air, it'll air lock and need priming. Your Mega is Pre OEM, and will foul much sooner than post OEM. You may have got a load of bad fuel along the way somewhere, shortening the filter life.

Welcome to the forum and good luck!


Adub

A fouled filter will cause the same issue as above, but may not be the problem. Your problem is more likely a poor seal at your filter. It's quite common. A tiny leak may pass air under suction, but not leak fuel under pressure, like priming. If you have recently (in last thousand or so miles) changed the filter, try loosening and retightening it. Make sure both top seals, inner and outer, are engaging properly. The O-ring has a tendency squirm out of place when they are installed. Use some grease on it and make sure it stays in the groove. You should also be tightening it with a strap wrench. Hand tight rarely works.

Another possibility could be a failed fuel cap. If the vent has failed, the temp swings can cause high vacuum in the tank when they cool down. Leave the fuel cap loosened for a little while. If the problem doesn't happen again, replace the cap.

Remember, these engines don't have a lift pump in the traditional sense unless you add one. The fuel is drawn up from the tank by a low pressure pump, built into the high pressure pump. They are not self priming. They do handle air while the engine is running, but will air lock when shut off or cooled down.

[ADub]

So far today, the truck hasn't done it, buts its much colder out today. I planned on changing the filter this weekend.

[Kennedy]

Two solutions to this: 1) install the air bypass orifice in the filter post and the air will pass like it normally does. 2) Install a lift pum to keep the fuel under pressure.

My New Years resolution is to get the lift pump and control harness finished and ready to go ASAP.

[babrom]

Thanks for the quick response. DmaxMaverick, I have already change the OEM Filter and the Mega filter but will check proper sealing and tightness. Funny you said that about the fuel. If I use BP(Amoco) diesel it will go 3 maybe 4 day before bleeding. Thanks. John, You said something about installing a air bypass orfice in the filter post. Can you explain more about that? Or should I wait for the lift pump and harness. Thanks