Roosa Master Injector Pump Problems

Colin King

Well-known Member
Sorry guys, forgot my camera before heading out to my friend's shop, so no photos today.

We're having some fuel problems. We bled the fuel filter. Then tightened and cracked open the pump to injector lines. Couldn't get anything but a dribble of fuel from any of the cracked lines with the engine turning over. Since this engine and pump had been sitting for a while unused, we thought we would try with the pump from the other engine.

After setting the timing and swapping pumps, I hit the starter button. Engine popped right off and ran for 1-2 seconds. Then nothing. Again, we checked for fuel at the injectors. Nothing but a dribble would come out.

Is there something I am missing in the bleeding process? There is plenty of fuel getting into the pump body itself.

After doing some research on the forum, I found a post from Bob about checking for a stuck metering valve and also a post from JD Seller about the decomposition of the flex ring. Are those the next steps to troubleshooting at this point?

In the good news department, the starter motor builds oil pressure to at least 40psi. We did not do anything to prime the oil pump, just cranked the engine until she showed pressure. I'm currently loving that new ring gear :)

Thanks!!
Colin
 
Take the pump timing cover back off and see if the front timing mark plate is still turning when engine is cranked over, if so try to start it with the cover off while fuel comes out. If it runs then there is a blockage in the return side, usually from the pump retainer ring breaking requiring pump repair. If it does not turn head is seized which breaks the drive shaft. Was there TWO washers on each banjo line bolt? If one is left off the bolt will bottom and seize the head too.
 
Thank you, Dieseltech! I'll do that check with the timing cover removed.

What is the banjo line bolt? The bolts that mount the pump to the block?

Colin
 
The banjo bolts are the injector to pump line bolts, they have a sealing washer on EACH side of the banjo. If one is dropped or left off it will cause major pump damage.
 
Gotchya. We didn't remove the lines from the pump, so I will have to check on the washers. I am guessing that they are there as both pumps are off engines that had been working, either prior to crankshaft breakage (engine 1) or storage (engine 2).

Colin
 
How long did the second pump sit in storage? It may need a good internal cleaning if the fuel turned stale and varnished several close fitting internal parts. I see that often with salvage yard pumps I work on.
 
There have been a few posts on this forum from guys who could not get fuel to the injectors with the RM pump using the starter to turn the engine. It happened to me once with an 841D I was trying to get started after it had sat for a while. I finally gave up and hooked a tow chain to it with my 861D on the other end. I put it in 4th gear and once it was rolling along at speed I let the clutch pedal up. The tractor didn't go 50' and the engine fired off.
I have run my 861D fuel tank dry a couple of times and after filling the tank and bleeding the fuel system it will not start using the starter. With the engine cranking I squirt a short blast of ether into the air intake and it fires off. I may have to give it another short blast or two to keep it running until all of the air is purged and then it is back to normal.
Other guys have had luck with holding a gasoline soaked rag over the air intake while cranking the engine.
If I were you I'd try the gas rag first and if that doesn't work then try to pull start your 961D before I did anything else. I realize the weather up where you are may be a problem right now with pull starting but I'd do that before I got too involved in swapping pumps, etc. Put the RM pump on the engine that it had on it when the crank broke because you know that pump was good a few months ago. Good luck.
 

When bleeding and loosening the lines,, only a tiny bit will come out.. so if it has fluid coming out of the lines, tighten them down... your getting close...
 
We got it to squirt a couple of times out of 1 and 4, but then just a dribble. Nothing more than a dribble out of 2 & 3, so it's not building up pressure.

Pulled the pump off and inspected for "coffee grounds." They were present, so the flex ring appears to be bad.

Colin
 

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