57 bcr Posted October 12, 2016 Share Posted October 12, 2016 My '88 R's engine won't idle unless the throttle is pulled out. Push it back in,and it stops. It has an AMBAC pump on it. Governor issue? Thanks in advance (no pun intended). Al Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment Share on other sites More sharing options...
fjh Posted October 12, 2016 Share Posted October 12, 2016 The idle adjustment screw is in front of the trottle lever 1 Quote Link to comment Share on other sites More sharing options...
j hancock Posted October 12, 2016 Share Posted October 12, 2016 While you are there, double check that the throttle arm is tight to the pump shaft and in good condition. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
57 bcr Posted October 13, 2016 Author Share Posted October 13, 2016 Thanks guys,will check on those when I get back to it,this weekend. Al Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment Share on other sites More sharing options...
57 bcr Posted October 8, 2020 Author Share Posted October 8, 2020 Okay, it's only been 4 years since I posted this problem! Thought I'd let the BMT community know what fixed my situation. Thank you fjh for your suggestion on adjusting the idle screw. There was not much adjustment left on the screw,and it was frozen bad. Found another idle screw/locknut from a donor engine. Worked well enough to give me the required idle speed! That problem solved! Had another problem on losing prime,if not starting the truck in 4-5 days. A veteran MACK wrench,said right off the bat "overflow valve on the pump". Sure enough took it apart. The spring was broken! Replaced it. Now it starts in a couple revs,after being parked for weeks! Beautiful! Hope this helps at least 1 more MACK owner out there. Thanks to all of you guys for your suggestions. Much appreciated! Al 1 1 Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment Share on other sites More sharing options...
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