I just purchased my 1985 F150 as sort of a project truck. Biggest issue I have it it takes about 20 minutes to start up. It will turn over on the first try, but I need to keep my foot on the gas to keep the engine running. If I remove it before the engine temp gauge reaches 1/4 to 1/2 the engine dies. Any Ideas????
Once it is warm the truck runs great ... other than no muffler and it needs a rear break job. The engine looks like it has been "MacGyver'd" but it does run once warm.
Any help would be greatly appreciated.
Scott

 

If a lot of amateur makeshift repairs have been done to it, best you buy a Haynes or similar manual, and go through all the vacuum and pollution stuff and make sure it's all connected and working....others who know more hopefully will chip in. The clue being it works when it's warm, something's not opening or closing properly, I guess.

That vintage of engine probably has the vacuum switch thing in the aircleaner that draws warm air from around the manifold when the engine's cool or air is cold. That's one possibility.

 

Check the EGR. It seems to not want to run in the 'closed loop' position, in which the EGR is bypassed. After it warms up, it goes top 'open loop' and runs fine. If the vacuum solenoid for the EGR is bad, it's trying to run in the 'open loop' while cold, and won't run.