What could be wrong if my F-150 truck has a high idle on start up and then dies?

Answer by  hypertech (690)

If the truck idles at high rpm then immediately dies, there could be a few possible problems. You may have a vacuum leak. You'll have to check whether this is from the vacuum lines or if the intake manifold is loose. Another possible but less likely problem is that your mass airflow sensor has gone bad.

Answer by  hibpmgirl (2166)

This could easily be the distributor. You can have it tested. Take your car to any auto parts store, like auto zone and they can see if your vehicle is throwing codes. If you can manage it replacing the distributor and its components is drastically cheaper if you do it yourself.

Answer by  smac972 (179)

The first suspect would be an air leak so I'd check your vacuum unit. If you're confident that is not the problem, investigate your idle air control system.

Answer by  bin53 (76)

If it is an older F-150 (80s early 90s)try replacing the spark plugs. We have an older Ford that does the same thing. When replacing the plugs check for a clean spark plug, you may have a bad plug wire on that one.

Answer by  richmiller3214 (138)

The choke could be stuck so it runs with a high idle due to straight fuel being pumped into the carb and will die if air isn't mixing with fuel.

Answer by  Amber40 (24961)

I would check to make sure that your idle air control vale is both clean and functioning properly because this could be cause the high rpm. Another thing to check is whether or not there is a vacuum leak. This could explain the high idle and possibly the dieing also.

Answer by  champaign9497 (11977)

There are a few things that can cause that a few of the most common are the fule filter may be plugged another thing coul be you have bad spark plugs Or your fuel pump or injecters may not be working correctly you can do a net search for more details.