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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Tikvah on September 10, 2013, 01:35:45 PM

Title: Air in fuel system.
Post by: Tikvah on September 10, 2013, 01:35:45 PM
They changed the fuel filters and now it won't start.

I know they filled the filters.

Ideas?
Title: Re: Air in fuel system.
Post by: luvrbus on September 10, 2013, 01:43:19 PM
Remove the plug in the top of the filter base use a bottle,electric pump or a garden sprayer and pressure the system with fuel  it will fire on a MCI the fuel pressure switch needs pressure
Title: Re: Air in fuel system.
Post by: Tikvah on September 10, 2013, 02:25:29 PM
That did it.  They actually put a little air pressure in the tank to get fuel out the lines.  Then reconnected and fired.  Stalled once, then stayed running.
Title: Re: Air in fuel system.
Post by: Sam 4106 on September 10, 2013, 03:14:18 PM
The trick I learned at Interstate Detroit Diesel last summer is to change one filter at a time. Start the engine after you fill and change primary filter and hold the engine at half throttle until the engine smoothes out. Repeat that with the secondary and you will not loose prime. Works well for me.

Good luck, Sam
Title: Re: Air in fuel system.
Post by: Geoff on September 10, 2013, 04:10:53 PM
The basic procedure is to fill the new filters before putting them on, then make sure the engine is reved up when you start it.  It will miss a little but the high rpms keep it running until it primes itself.

Oh, and make sure youi fill the new filters with CLEAN fuel, not some crap you have laying around.  I just had to rebuild an engine that someone primed the filters with dirty fuel.  Two of the injectors got plugged, and the worst one plugged all the injector holes but one which burned a hole in the piston.

(Special note to Clifford-- this is the MCI I worked on at your restaurant).

--Geoff
Title: Re: Air in fuel system.
Post by: gus on September 10, 2013, 06:46:37 PM
I've always used the same system as Sam, never any problems since I started doing it his way.
Title: Re: Air in fuel system.
Post by: bobofthenorth on September 11, 2013, 08:35:49 AM
What the other guys said but just in case I cut the valve stem out of an old inner tube so that I had about a 10 inch circle of rubber with a valve stem in the middle.  If you wrap that around your fuel filler and tie it with a zip tie or hose clamp its easy to add enough pressure to the tank to fill the lines.
Title: Re: Air in fuel system.
Post by: bevans6 on September 11, 2013, 10:37:03 AM
Being extremely lazy I just turn the priming pump on for 10 seconds and then start normally.

Brian
Title: Re: Air in fuel system.
Post by: chessie4905 on September 11, 2013, 10:41:00 AM
   Spend the money and add an electric fuel pump. Then, you can change  fuel filters yourself, and save enough money for the fuel pump, fittings, wiring,and etc., even labor if you can't do it yourself.
Especially handy if you accidently run the fuel in tank too low. :o
Title: Re: Air in fuel system.
Post by: bobofthenorth on September 11, 2013, 10:45:50 AM
Being much lazier than Brian I bought the primer pump, stuck it in a bay and now carry it around as baggage, having never got around to installing it.
Title: Re: Air in fuel system.
Post by: Oonrahnjay on September 11, 2013, 11:07:15 AM
Quote from: chessie4905 on September 11, 2013, 10:41:00 AMSpend the money and add an electric fuel pump. Then, you can change  fuel filters yourself, and save enough money for the fuel pump, fittings, wiring,and etc., even labor if you can't do it yourself.
Especially handy if you accidently run the fuel in tank too low. :o   

     Yeah.  And you only run out of fuel - get bad fuel and have to drain - have to park on a steep slope and uncover the pickup point - etc. it's always on dark rainy nights.  Purely for the peace of mind, the few $$$ one costs is worth it.