Truecountry

whats a decent compression tester for this engine?

called a couple of mack dealers and talked to shop guys and one said drain oil drop oil pan and look at lifters and cam one said pull head and check valves they may be burnt one said ill call you back tomorrow morning

yes other mechanic said spring came off .. swapped out rocker and checked did valve adjustments again on number 1 and still missing ..cracked fuel line at eup and its plenty of fuel pressure there ..even got someone to turn engine by ratchet adapter on flywheel to see the valve train go up and down .pulled eup and cup saw pin you were talking about its there ..turned flywheel to look at cam and I see nothing wrong I hook computer up and no codes active or unactive even tried to do a engine compression test with computer but it didn't do right ...did cylinder cut out and its #1 recalibrated the 2 eup that where swapped and still #1

I pulled the pump once that's is ..but couldn't get cup out and I also felt a slot cut in cup oblong which way does that go up or down

yes

I didn't replace unit pump another older mech did swap new one and swap it with number 2 and he also swapped injectors 1 and 3 Nothing wacky on valve adjustment on number one I do have spare rockers to swap with number one but this thing is misfire from cold start sounds like exhaust

This is my first Mack engine I ever worked on ... I took a job working for a construction company and they have all Mack trucks my old company had all cummins or caterpillars Ok this problem with 2006 mack with ai-427 happened before I went to work with them . Heres what I know number one cylinder electric fuel pump came apart and had a misfire on 1 fuel pump was replaced still misfire ..injectors were swapped 1 to 3 and still misfire on 1 Ok now I download service and repair manual for the engine and start checking for fuel at pump check for electrical pulse at pump I pull both valve covers and start turning flywheel to do a check on overhead valve adjustment and 4,5,6 rocker shaft is broken seems bolts backed out once and they lock tite them back down . I get another rocker shaft remember this is 4,5,6 still misfire on 1 after shaft was replaced im not throwing parts at this I want to fix this I hook computer to truck and I see only one code over voltage or open engine brake I cant remember code can a power leash engine brake cause misfire on number 1 or injector cup?