aclem Posted September 3, 2013 Share Posted September 3, 2013 our mack starts loosing boost right around 1600-1700 rpms. it flattens right out. has new turbo and air to air radiator on it. think injector pump is getting bad but hopefully you guys can help me out. It gallops if it sits and idles. been told if i remove cover off side of pump and theres brass pieces in bottom then its wore. dont know how true but hopefully i can get some help on this. Quote A.Clement Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/ Share on other sites More sharing options...
theakerstwo Posted September 3, 2013 Share Posted September 3, 2013 . First thing is get some one to mash you gas pedal down and you go out and see if the throttle lever is all the way in go fast position. If that is ok then think of something else.Check for boost leaks and you need to do that with air pressure to the air/air cooler and plumbing with 25 psi.You will be checking for leaks and not just some small leaks that you find with soap and water on the hoses.If that is ok then check your fuel pressure and you need around 30 psi under load.Depends on what pump but it may have a aeroild valve diaphragm leaking air and that needs to be checked with 20 psi and see if it hold air pressure. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/#findComment-203339 Share on other sites More sharing options...
gearhead204 Posted September 3, 2013 Share Posted September 3, 2013 the throttle link should have a spring centered lever on the side of the injection pump. have some one smash down fuel pedal and see if lever moves independent of pump shaft if no secondary movement is seen clean dirt from behind pedal, if that don't fix.adjust linkage until over travel is obtained at pump lever. once this is done begin as glenn said to find other problems Quote Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/#findComment-203374 Share on other sites More sharing options...
arlogger Posted October 2, 2013 Share Posted October 2, 2013 block off the aeroild valve and crimp off the line going back to the injector pump from the aeroild valve and she run like a scalded dog !!! Quote Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/#findComment-209575 Share on other sites More sharing options...
rsb502 Posted October 3, 2013 Share Posted October 3, 2013 if its dropping boost around 1700 its running out of fuel, fuel filters, throttle linkage, aneroid valve, lift pump,etc. Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/#findComment-209721 Share on other sites More sharing options...
boyd Posted October 4, 2013 Share Posted October 4, 2013 Aneroid valve/Puff limiter can be plugged off, it will be a plastic 1/4 line going from fuel pump to your air intake manifold. By doing this will allow the plunger in the pump to be Actuated all time... This will cause engine to smoke more than normal though... While doing MPG tests in the mid to late 80s it would hurt your fuel mileage 2 or 3 tenths... Again a lot depends on driver.... Quote Link to comment https://www.bigmacktrucks.com/topic/32588-losing-boost-after-1600-1700-rpms-e6-300/#findComment-210062 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.