Joey Mack Posted March 29, 2022 Share Posted March 29, 2022 Hi guy's.. I have a customer with an '87 Superliner, E-6 4 Valve, Ambach inj. pump.. he called me today and said... "It did it again" !.. He fired it up when cold, and it revved passed 2000 and settled at 1900 rpm.. I looked at this truck 3 weeks ago for this issue. I pulled the CAC hose of on the intake side and there was no oil present. i did a basic visual inspection and nothing jumped out at me. I took the intake of the turbo, and it is dry and the turbine is in great shape and not sloppy.. I have almost no knowledge of the inner workings of this injection pump, but I was wondering if the rack is sticking. He was not able to pull the throttle stop and shut it down, it just kept going, so he jammed it into high gear and stalled it out. My only thought is the rack stuck open, I think he said the throttle pedal had no affect.. Thank you in advance, jojo Quote Link to comment Share on other sites More sharing options...
MACKS Posted March 29, 2022 Share Posted March 29, 2022 That happened to one of my trucks years back tho much older and not a four valve,it was the governor at fault,I remember taking the back off the pump and replacing something round,lol.. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted March 29, 2022 Author Share Posted March 29, 2022 im tempted to open it up, but my customer just wants me to pull the pump. I think it a 'knee jerk reaction' to pull the pump.. I have the svc manual for it so, at leaste I have that going for me.. I may just pull the gov. cover off and see if there is something broken.. I hope Glenn add's his thought's, and Vlad, and hell, once again I can go on and on... jojo Quote Link to comment Share on other sites More sharing options...
MACKS Posted March 29, 2022 Share Posted March 29, 2022 31 minutes ago, Joey Mack said: im tempted to open it up, but my customer just wants me to pull the pump. I think it a 'knee jerk reaction' to pull the pump.. I have the svc manual for it so, at leaste I have that going for me.. I may just pull the gov. cover off and see if there is something broken.. I hope Glenn add's his thought's, and Vlad, and hell, once again I can go on and on... jojo My problem may have been different not sure but when I started it cold it would race up and then come back to normal,it was getting worse every time I started it,I would pull the back cover and have a look.. Quote Link to comment Share on other sites More sharing options...
Popular Post theakerstwo Posted March 29, 2022 Popular Post Share Posted March 29, 2022 Joey make sure there is no water in the fuel filters because that is what scores the plungers.If not any water then it may still be plungers sticking because the fuel now has little lub in it.Now days when one sticks from sitting for a period of time they can stick the plunger to the barrel and that stops the rack movement.I have be able to remove the supply line and return line on the injection pump and fill the galley of the pump housing with some PB blaster or something like that and let it set a few days.Remove the governor cover and you can us a screw driver to try to move the rack.Do this for awhile but dont force any thing.If it moves then crank the engine over some then work with moving the rack.If it frees up you can work the throttle and the stop to get the rack to go forward and backwards.Do this untill when you pull stop it will pull the rack back to the governor.Then watch the rack as you push the stop back in and the rack should move to the front of the engine some and do it freely with out mashing on the throttle.Then put some lub in the fuel of some kind.The plungers can also stick up as the cam forces them up and they can stick up but in most cases if you get the rack to move the plungers will fall back down on the cam lifters.If they have stuck from water i would not try any repairs cause damage have been done to the metal of the plungers and you cant fix that with out new plungers and barrels.Maybe you should remove the side plate first and see if any plungers are stuck up.With the galley full of PB blaster or acetone.If one is stuck up some times you can pry it down and then turn the engine watching the rest. 2 2 Quote glenn akers Link to comment Share on other sites More sharing options...
Joey Mack Posted March 30, 2022 Author Share Posted March 30, 2022 Glenn, thank you so very much!! I know i said i have never been inside this pump, but.... I truly understood everything you said.. I will do exactly what you said... I have run this truck on the yard many times, and it only act up when it sits, and the last time I was there, I saw the fuel filter next to the injection pump was old.. and I told the owner that it needed to be replaced, he said he didnt even know there was one there.. the day I was there I couldnt spend a lot of time because I was in between road call's.. Once again, Glenn, Thank you, jojo 1 1 Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted March 30, 2022 Share Posted March 30, 2022 About a year ago a friend of mine that runs a dump truck were i was working had same problem and it is a 1966 R model but it was trying to run away as he was bring it out to do some work on it.We pulls a filter and it was half full of water.I had a spare pump so we installed it and for a few weeks i tried to get it to free up and could not.We found the fuel tank cap had a hole in the top and rail was dripping down the side of the door into the tank. 2 Quote glenn akers Link to comment Share on other sites More sharing options...
theakerstwo Posted March 30, 2022 Share Posted March 30, 2022 1 hour ago, MACKS said: My problem may have been different not sure but when I started it cold it would race up and then come back to normal,it was getting worse every time I started it,I would pull the back cover and have a look.. A sticky rack or worn weights in the governor can do that also. 2 Quote glenn akers Link to comment Share on other sites More sharing options...
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