Hey guys. My F150 has a problem with cold starting. Not cold weather starting (as the temperature here has been over 100 for like a month now). but like sitting overnight then starting. My engine is the 5.8 litre H.O. with the 4 bbl carb. To start it takes pumping the gas pedal madly (probably 10 to 20 times) then hitting the starter, after which the engine usually fires and dies. Go through this about 3 to 5 times to get the engine to keep running (with foot on the gas slightly for a fast idle). Then put the automatic trans in gear and it dies immediately (especially putting it in reverse), Repeat the process another 3 to 5 times and I can usually take off. I've checked the carb choke and it appears to be functioning normally (closes when i step on the gas pedal with the engine cold, then opens fully when engine is warm. Hooked a vacuum guage to the port on the back of the intake manifold and it reads 16 to 18 inches, although the needle flutters between 16 and 18 constantly. While I had the vacuum guage hooked up I unplugged the vacuum line at the base of the carb and the engine died immediately. Engine has a block off plate on the back of the manifold where the EGR would be. When the engine is warm it usually fires with just touching the key and will drive away fine. Any help would be appreciated. Thanks.

 

i would have a professional check the carb and get it jetted. that would have to be the possible fix. or your fuel pump may be going out. but most likely its something like being out of time or a carb problem.

 

Had a similar 'cold start' problem with my '85 351 HO with carb. Ended up being a small gas leak from a bad gasket. The gas was slowly leaking out while the vehicle sat overnight and in the morning it was tough to start. Rest of the day just fine until it sat all night again. Replaced the gasket and the problem was solved.

Dont know if yours will be that easy, but I figured it was worth letting you know.

 

on my 84 ford f150 300 if it got cold over night,and i try to go out and start the truck it wont do anything,butr if i jumped started it it would start.

 

FirstFordTruck, you said a gasket leak. Just wondering which gasket where? Thanks

 

I have to check with my buddy who did the work for the specifics and will get back with you.

 

Front of carburetor remove bowl cover. Inside is accelerator pump with gasket. Accelerator pump gasket had the slow leak. He replaced pump with gasket and I believe bowl cover gasket too.