Cummins big cam 350 vs 400
So an aneroid valve can cause a WOT run away situation, as well as the lack of power, since it was basically bypassing fuel right back into the pump just below the fuel solenoid and giving the engine all the fuel it wanted. Put the pump back on and it fired off as it should. So i had them put the aneroid block off in the pump so that I only have the dual feed lines coming out the top and the return on the rear of the pump. They said it was the motor back feeding fuel but the only difference between it and the NHC250 pump was that aneroid line.
They did not have anything hooked to that aneroid line. Took the pump back to the shop and bench tested it and it came back fine with 240 RP. Figured it had to be the pump so i put the small cam pump on and hooked it all up and everything was fine.
Cummins big cam 350 vs 400 cracked#
Cracked the manual shut off valve and when she started she ran up to 1100rpms and i made sure the throttle was closed and shut the shut off valve again. I mean just deafing when you are sitting next to it. When she caught fuel she ran wide open to the governor. AFC vent, Aneroid Line, Fuel feed line and the return on the rear gear pump. Put the pump on the NTC400 and hooked all the lines back up. so they lapped it and put it back together with the rebuild. I had my pump rebuilt and they went thru it and said the aneroid valve checked out just fine. Complete Bigcam mechanical take out, with water jacket, with air NH/NT 855 NTC-FOR 400. I will bump this since I just had an issue with an aneroid valve on the BCIII i put in my 923. The rest of the task is very straightforward.īTW, yes, the aneroid valve was bad, making my fire breathing Big Cam 400 perform like a wimpy 250. This requires a 12 point, 7/16 swivel socket, such as a Proto 5274 (see pic). The real trick to pulling the pump is the upper rear mounting bolt. To access the pump rear lower mounting bolt, I had to remove the power steering pump, a simple 2 bolt removal. The task is simplified if you remove the fender, a simple 6 bolt task in my case (M915). So I got busy and pulled the pump and sent it for rebuild. I suspected my aneroid valve was bad, thanks to input from reb87 and others on this site.
Cummins big cam 350 vs 400 full#
If this valve is not working, the pump will never produce full pressure, and the engine will have low power. In my case, the pump is equipped with an aneroid valve, which further adjusts fuel pressure based on turbocharger boost. If the pump is not working well, hard starting, low power and other issues can result. First of all, the purpose of the Cummins PT pump is to draw diesel from the fuel tank, and raise the pressure in proportion to throttle input, and send the higher pressure fuel to the injectors, where it is further pressurized for injection. The 400 Cummins in the Superliner which I am not sure if it is a 350 or 400 boost needle will jump up to 30 + lbs of boost, which means it is at least a 600hp engine.Here is some info for anyone faced with this task. Remember this, Air is free, give it all it wants. Seen that happen a few times where the lines were detereating and restricting fuel flow. Also make sure your fuel supply lines are big enough and in good order. I do those things before getting into the pump. A "Fast Fuel" will make a big improvement also. respond well get your self a dual feed kit. I think its for every 1 lb to 1.5 lbs of boost a B.C.