I have a D4 2T model that does not get enough fuel. It has clean filters and a clean by pass valve, gets flow out of the bleeders on the pumps but not as strong as would be expected. Also not very strong at the injectors either. The fuel rack moves good now as it was stuck. Fuel flows strong out of the top of the filter housing. It is being gravity fed to the transfer pump. It does not have a fuel pressure gauge so I am getting one. In the past I remember engines running on very low pressure as long as it got to the pumps. I am suspecting a bad transfer pump. Can any one tell me how much pressure is needed at the gauge or any other Ideas? I have never had a problem like this before.
You all are a good group of fellows

You need at least 15 lbs. or more & it could be the transfer pump is getting worn but try this before you do any more & that,s to stretch the spring that seats the relief valve there on the side of the transfer pump.Also look at the check valve itself & see if it,s worn & also the body where it seats. I would draw file that area of the seat flat & smooth if it was worn from the plunger (check valve).If pressure is still down then a pump overhaul may be needed.

The key is getting that pressure gage. If the pump is worn out it won't come close to lifting the relief valve. New pressure was 30 psi, they get kind of iffy at 10psi or less.

"Old wrote:

The key is getting that pressure gage. If the pump is worn out it won't come close to lifting the relief valve. New pressure was 30 psi, they get kind of iffy at 10psi or less.

Thanks fellows,
It sure is good to know you all. Today after posting my question I hooked up an electric fuel boost pump and got it running. Also found a pressure gauge from another old cat here. Once it was running the pressure was in the operating range. I did find it must be low on compression as it slobbers from the exhaust alot and had to give it much starting fluid to get it going. So now that is one of next winters projects. At least the oil pressure was good and I know now what condition the engine is in.
Your information is very much appreciated and will be useful when I get back to it next winter.
Sincerely, Frank Robertson, Soumalinen

Try working the tractor hard under as full a load as you can for a half a day & see if it helps the slobber as this could help it unless the liners & rings are shot.Light loads & idling for extended time will glaze the walls of the liners and cause the slobbering too but as I suggested it just might be worn out.