<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> Hi I have a 1984 Bronco with a 351W and C6 transmission. The motor idles and will rev up and sounds real good but if it’s under a load it bearly has enough power to pull it self up a steep grade. Help.
<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]-->

 

We need a little more info. My first guess would be fuel filter or weak fuel oump

 

I know if it set a week or more it takes quite awhile for the fuel to get to the carburetor. Fuel filter is one of the clear plastic inline one looks fine inside; no sediment in it.

 

Weak fuel pump? Can you pressure check it? Other thing that comes to mind is that there is a screen on the pickup in the tank that may be plugged.

 

Do you think I could pull the fuel line after inline filter and start the truck?

 

Do ya got an electric fuel pump or manual?

 

manual fuel pump

 

I wouldn't start the engine with the fuel line off. Maybe pull the coil wire off so it don't start and crank it just a few seconds with the fuel line in a can to see if it is pumping much fuel

 

Can we rule out the tranny slipping?

 

I can put a ??? 30 degree dirt bank in front of it and try to climb it and it will get to the point where i can have the gas pedal to the floor and it just lugs down it doesn't spin the tires, but its like it has no torque. I don't feel any slipping or hear the motor rev up quite the opposite just lugs. It's the same on flat ground dragging a log.

 

does the motor rev up find while in neutral? manual fuel pumps are cheap and if its old i would start there. when was the motor tuned up last? be sure to run a regular copper plug also, no platinums or fancy plugs necessary. might be time for a carb rebuild also.

hows the tranny fluid? full? need replaced?

 

yes motor does rev up in neutral, it is full, does not smell burnt. Agree will start with the fuel pump.

 

Did ya just get this rig and it was like this? Or have ya had it for some time and it worked good until this developed? If so what (if anything) may you have done to it recently?

 

Had it since 1985 and always ran great. I believe the trans was serviced in 1993 and motor rebuilt in 1995. it ran good after rebuild but never really great again. it has been used very very little since then mostly around the house. after sitting around for several years with little use is when the lack of power challange started. So about 60,000 on trans and 20,000 on motor.

 

I changed the sparkplugs and wires, air and inline gas filter and rebuilt the carb a couple years back.