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May 30, 2006 | 07:59 PM

1972ford_f-100

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Help !!!!!

hey guys i just bought a 84 150 ext. cab long box 300-6 i replaced the dist cap,the wires,rotor,plugs and the thing runs rough as all hell(squze the languige,and the bad spelling lol)but i did the timing and it still runs rough,like its missing,well drving i try to acellerate it seems to be missing but i checked the ohms on everything and its all good,the only thing i havent checked is the icm,but i cant seem to find it...but wut else would cause this.... all my vac lines are good,no leaks. i tightend down the carb....oh i replaced the fuel filter too... all help is greatly apriciated thx

May 31, 2006 | 12:14 AM

Bdox

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Joined: Sep 2005

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From: Lake Tahoe, Nevada

Double check your firing order!! If all OK, run a compression test.

May 31, 2006 | 04:27 AM

srercrcr

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My truck is exactly like yours.
You should see a link below.
You did well to get the electrical side freshened up....that will pay off for many miles once you find the current problem.
My experience points me to the EGR and the carb itself.
Any history with them?

May 31, 2006 | 05:30 AM

Dungeon_Master

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From: Connecticut

What did you set the timing at 10º OR 12º BTDC
All spark gaps call for .042-.046
All other carb body numbers except listed below were 10º BTDC fast idle rpm 1600 -carb idle rpm 600-700,* note 550-600 rpm with auto trans in drive*
carb body number 9-77J-R12 is 12º - fast idle rpm 1600 -carb idle rpm 700, 600 rpm for TSP off
carb body number 9-78J-R00 is 12º - fast idle rpm 1600 - carb idle rpm 550
carb body number 9-78J-R11 is 12º - fast idle rpm 1600 - carb idle rpm 550
83 was funky it had 6º,10º 12º BTDC's
85-86 were all 10º BTDC

Last edited by Dungeon_Master; May 31, 2006 at 05:34 AM.

May 31, 2006 | 01:28 PM

1972ford_f-100

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i checked the firing order it is corect,i think the egr may be messed up cause i checked it and it didnt pull push nothing so could that be it and the truck has 143,ooo on it with never having a carb rebuild ,so would i be wise to rebuild it

May 31, 2006 | 02:27 PM

Piffery1

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Joined: Jun 2004

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From: Niceville, FL.

Sounds like EGR Valve is stuck open. If it's the "back pressure type" EGR valve, I don't think it will move without the engine running. I'd take it off and clean it (including the ports/passages it mates with). With that many miles it all probably needs the cleaning even if it's not the main problem. Or you could make a temporary block off out of a piece of heavy gasket material placed between the EGR valve and its port to see if that's the problem.