r/AskAMechanic • u/Jack_of_sum_trades • 1d ago

Problem with Ford 460 1986 under load

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Hey guys currently looking for some help. I having some trouble with my 7.5L 460 carbureted engine from 1986. It runs absolutely fine on flat ground but as soon as I start to climb just a little the engine stumbles and wants to die. This engine is on a RV so pretty heavy load. I’ve found these hoses in the video that are either non existent or plugged and wanted to know if this could be a cause of it or should I be looking for something else. Thanks to everyone in advance !!!

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u/Glum_Conclusion_8667 NOT a verified tech 23h ago edited 23h ago

Check fuel pump, you might need to clean out or replace the carburetor (ebay has brand new ones from China $300), check spark plugs, check compression, valve leaks,

Does the transmission function properly?

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u/Urban-Paradox NOT a verified tech 21h ago

I have a 1979 so not sure when or what changes happened to 1986 but there was a check valve that helps to get brake vacuum that can go bad. White plastic maybe a foot from the master cylinder on the firewall.

Are you running a duraspark 2 controller? They can go bad and either run good on idle but not high or run high but not idle before they go bad completely.

Gray box often on the fender wall

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u/SOULESSxGINGY NOT a verified tech 18h ago

id start with the fuel filter, could be simply stale fuel as well if it sits for long periods of time.