MCI wont start

[Busted Knuckle]

Again Clifford good catch! I forgot that this was a C3 and yes ALL C3's I have ever been around have had the lift pump! The switch for it is on the same panel as the rear start/stop and engine compartment light switches!
 BK  

Viking,
Find that switch and start the bus while holding the switch on and have someone accelerate the engine RPM's up at about 13-1500 RPM for a few mins while you hold that switch on. It takes a little time to suck that fuel back up from the tank after losing prime and you need it at a fast idle for a short period to make sure it's drawing it and not just sucking your filters dry!

[Ed Hackenbruch]

Did you figure out what the problem was?

[viking1]

I have a new pump on order, should have it in a day or two. 95 bucks from Iron Man in LA. Hope to have it in over the weekend. Will let you know as soon as its in.

[jjrbus]

Is there a fuel shut off valve near your filters? One time some idiot shut off the valve. The bus started and ran then shut off. I asked for help with it and the forum pointed to everything but the problem 

No matter where I go that same idiot shows up and causes me problems.
                                                                                                          JIm

[viking1]

Ok! Now I am just more frustrated and confused. I put the new pump on. Primed it and it ran for about 5 min and then died. I then put 20 gallons in the tank just because and I am now showing a half tank. Primed it and again it started and ran for about 5 min.

I wonder if I am priming it right,

I filled both fuel filters with diesel and got myself a 12 volt fuel pump that I connected to the first fuel filter (also tried the #2 filter, runs both ways). I then pumped fuel while cranking the engine with a valve open on the 2nd fuel filter until fuel started coming out, at that point the bus starts and i close the valve. I ran approx 1 to 2 gallons through it this way before disconecting the 12 volt fuel pump. After i remove the 12 volt fuel pump she will run in high idle for approx 5 min and then she dies. I have also diconected the fuel line just before the fuel filter and put it in a can and it runs fine this way. So as some one suggested in an earlier post, it must have a leak, must be sucking air somewhere between the tank and the fuel line to the fuel filter. "SO" how the heck do you trace down this kind of air leak. Any suggestions.

I was even considering taking a tank out of my boat and riging it up with a 12 volt pump and mounting it in the rear so I would be able to drive it to ABC Bus in Orange County.

Any help or ideas would be greatly appreciated. And I did check the shut of valve and it is open.


Regards,

ONE FRUSTRATED BUS NUT

[luvrbus]

As fore mention that bus has a lift pump 

good luck

[viking1]

Lift Pump? please explain

[robertglines1]

Read BK's post at top of page. he has hands on experience with your problem. Or PM him he will prob give you a call and walk you thru it.  I don't know enough about it myself to help.  Sound like to me like a pump like a car has inside a gas tank  is what they are talking about. Look around fuel tank area and see if you have a couple power wires running into tank around area where hoses run into tank. or a external pump/electric

[robertglines1]

Is it shutting off when air pressure reaches 70lb or does it do it at any air pressure above or below that? Is air after 5 minutes over 110 lbs?

[viking1]

No, It does not matter what the air is at. I aired it all the way up when I had it running.I looked at the tank, I have a few electrical wires at the top of the tank but Im thinking thats for the fuel gauge. I called ABC Bus and the guy there said I dont have a lift up pump and I could not find a switch for it either. getting very frustrated. So much for the weekend trip.

[Lin]

Get use to being frustrated sometimes.  This will happen periodically.  One real drag is that the rebuilt fuel pumps are sometimes bad too.  When mine was changed, it took 2 to get one that worked.  If you rig it so the fuel pump pulls from an external can of diesel, you should be able to see if the pump is good.  Even a small crack in a fuel line will let the pump suck air.  Can you hook up your electric pump in line and see if it runs that way to try to disqualify the leak theory.

[robertglines1]

I have a 89 prevost with a 8-V92 ddecII about same set up as yours. Leaving tank check valve first then line goes to inside engine compartment behind right rear tag wheel to 1st fuel filter then to  primary& secondary then to transfer pump.( I have put on two transferr pumps)                                   Next it goes thru the ddec module where it acts as a coolant for the module. Be careful with these fittings easy to break the housing they screw into. thru injectors to return line to tank.  If you use your boat tank you will be returning a large amount of the fuel to the tank in the bus so you cannot depend on using all of it(maybe 1/2)   Possibly disconnect primary supply line from tank and attach temporary spliced in extension pickup piece of line in thru fuel gauge port to eliminate possible damaged pick up. Could add a in line ck valve if that test doesn't work to test to see condition of ck valve that is suppose to be in the system(prevents   fuel from flowing back into tank and draining filters etc)   You said it was definitely fuel!  The only other real problem I have had with a similar set of symptoms was a bad low coolant sensor. ( Would not leave fuel filters half full.) Would spin but would not start.

[Ed Hackenbruch]

Did you actually, physically, measure the amount of fuel in your tank, or are you just going by the gauge?  When mine is full to the brim it only reads 3/4 full. Yours could be the opposite and read 1/2 full when really it is empty. If it was me i would completely fill the tank to the top and see if it runs before i started tearing things apart.  I have only lost prime one time and it took about 10 tries before i got it to keep running.

[robertglines1]

Question?  why would a electric pump work drawing out of tank and the mechanical pump not work? Did you put the electric pump in line drawing out of the tank?  Just trying to solve problem long distance here.  Could be crud in tank or something a simple as a rag sucked over intake;strange things get in tanks. Do need to verify fuel level physically. take a piece  of rubber hose and stick thru filler and ck level. Gauges can and do lie and get off with age  20 gal will only make a couple inches difference  in a big tank if it's level. and if tilted away from pick up,you get picture. Let's hope in the end it will be something simple and a How did I miss that!  Keep checking possibilities.

[Busted Knuckle]

Called ABC? Shoot they don't have a clue they sell & service Van Hools!

Seriously I bet it has the lift pump. Every c3 I've ever been  around has.