michigan 55a

[fullchoke]

It has a 353 detroit that I would like to get started. The emergency shutoff appeared to function and I had a big manual to cover the intake just in case. The prior owners could not remember the last time it ran and I think it could have been 15 to 20 years. After installing a new battery it started very easily but only ran 20 seconds and died like it ran out of fuel. I drained the old fuel from the tank and plan on changing the filters. It looks like fuel travels first to the primary filter, then to the pump then to the secondary filter then to the engine. I want to bleed air out at the secondary filter. That looks like an easy place to do it. Then I know the pump has suction and should not cavitate. If I pressurize the tank do I have to have the engine turning over to get fuel past the fuel pump? or can I expect to purge the air out of the fuel system to the secondary filter before I start cranking by only pressurizing the tank?

Thanks

 

[old-iron-habit]

You only have to fill both new fuel filters with fuel on your 3-53. They will usually start right up. One of the easiest diesels on the planet to start when run out of fuel. But fuel will go thru if you pressurize the tank. Use very little air, 5lbs or so is plenty. That equates to a lot of pressure in the tank walls over many square inches. Good luck and post pictures. One of the best engines every made to us screaming demon lovers.

 

[mitch504]

They will pass fuel through the lift pump with the engine stopped.

 

[oldseabee]

I didn't have much to do with the engines, but I do remember that there was a check valve in the supply line to the fuel pump to hold the fuel in the pump so it wouldn't drain back into the tank when the machine was shut down. after sitting for all that time it could be stuck shut so the pump couldn't get fuel, the engine could run just on the fuel in the injectors and lines for a few seconds.
The other thing was that there was a restrictor fitting in the return to tank line, I don't remember if it was under the valve cover or where the return line came out of the head, it's function was to make sure that the injectors stayed full of fuel, if the fuel pump is to weak to generate enough flow to cause enough back pressure to get the job done or some one had replaced it with a standard connector fitting.
Maybe one of you engine guys can correct me or at least forgive me for posting about a system that I know little about.

 

[fullchoke]

Thanks guys for the advice. She started so easily the 1st time, I was surprised, but slowed and died. I will try pressuring the tank to bleed the air out and I'll start with full filters. I've got brakes and fluid changes yet to do also before I can get her moving and stopping. Thanks again.

 

[fullchoke]

I would like to know where that check valve may be found. That would especially be needed if I can't get fuel to the secondary filter when I pressurize the fuel tank.

 

[old-iron-habit]

I didn't have much to do with the engines, but I do remember that there was a check valve in the supply line to the fuel pump to hold the fuel in the pump so it wouldn't drain back into the tank when the machine was shut down. after sitting for all that time it could be stuck shut so the pump couldn't get fuel, the engine could run just on the fuel in the injectors and lines for a few seconds.
The other thing was that there was a restrictor fitting in the return to tank line, I don't remember if it was under the valve cover or where the return line came out of the head, it's function was to make sure that the injectors stayed full of fuel, if the fuel pump is to weak to generate enough flow to cause enough back pressure to get the job done or some one had replaced it with a standard connector fitting.
Maybe one of you engine guys can correct me or at least forgive me for posting about a system that I know little about.

The restricter fitting screws into the side of the head with the return line coming off it. Should return a fair sized stream when engine is running correctly. I don't recall any check valve on any of my old screamers. May be dependent on where the tank is in relation to the engine. I do have one with an electric fuel pump that supplies fuel to the gear pump which boosts it to 60 PSI to the second filter.

 

[oldseabee]

I was looking at the fuel lines in the parts book for the Michigan 55A and it does show a check valve at the end of the supply line from the tank to the pump, on that machine the tank is lower then the the pump so drain back could have been a problem.

 

[fullchoke]

I was looking at the fuel lines in the parts book for the Michigan 55A and it does show a check valve at the end of the supply line from the tank to the pump, on that machine the tank is lower then the the pump so drain back could have been a problem.

Thanks for checking up on the the check valve. Is it in the fuel tank? I'm wondering if I should install an electric fuel pump? Would the pump circulate fuel back to the tank or would it build pressure and be self regulating as to the pressure it puts out?

 

[oldseabee]

Typically it would be right where the fuel goes into the pump, parts book shows it right at the end of the fuel hose, maybe even screws into the fuel pump, it would look like a connector.
As to the electric pump, it would depend on the volume of the pump, it is a through line through the injectors and back to tank except for that restricter coming out of the head, too much volume would give you more back pressure then you want.
Again I defer to the engine guys to say what pressure is too much, not sure how much pressure the original pump can take if the engine is not running but the electric pump is running before start up. Some electrics are pressure adjustable and some just are set to a range.

 

[Former Wrench]

The fuel pumps on 53's and 71's are all the same. It is extremely rare to have problems with one. The fuel system is enclosed and the pump has enough pick up to suck fuel from saddle tanks on a truck up to the engine mounted much higher in the frame.

Slang is primary and secondary filters. Actually the first one is a strainer (metal) and the second one is the filter (cloth sock looking). Once the engine in running, there should extremely slim odds of getting air into the fuel system. Make sure that nothing is pinching the no fuel (shut off) linkage. I wish I could see this because something does not seem right. Good luck.

 

[kshansen]

Normal running fuel pressure on a Detroit is 40-60 PSI.

 

[old-iron-habit]

About the only issues I have seen with the gear pump for the fuel is if the seal leaks on the drive side they can suck air at higher RPM. An east test is to use an electric pump to pressurize and see if it leaks out the drive end. Not at all comon though. A temporary fuel tank set high may do the same test.

 

[kshansen]

About the only issues I have seen with the gear pump for the fuel is if the seal leaks on the drive side they can suck air at higher RPM. An east test is to use an electric pump to pressurize and see if it leaks out the drive end. Not at all comon though. A temporary fuel tank set high may do the same test.

For those that might not know there are two seals in these gear pumps. One to seal the oil (drive side) and one to seal the fuel side. Depending on where the fuel tank is located (above or below the fuel pump) the fuel side seal needs to be installed the correct way to prevent fuel or air leaks. There are holes with 1/8 inch pipe threads do not put plugs in them or you culd have fuel getting in the oil if a seal goes bad.