88 F150/V8/5.0L - here's the details, before I bought this truck it sat a long time so over the past few months I've had to replace a lot of little things. Its had starting issues so so far i've replaced the battery, cables, starter motor and solenoid as they went out. Last month heater core broke and I started replacing it and all the heater hoses as I went and finally coolant temp. sensor - during this period the truck sat for about a month unstarted as I worked on it. Right towards the end we got a freeze for a week. Now I can't get it started. It started fine before the heater core/hose repairs. Battery is brand new and tested, working fine. Starter is brand new. Truck turns over but won't engage. My first thought is to check the fuel pump - as I know the battery/solenoid/starter are all fine. I replaced the filter already. Any other direction as to where to begin? Is there anything I could have done wrong replacing hoses to keep it from starting - unless the coolant temp sensor could be effecting it? All hoses are tight and snug. I did by an AZ sensor is there any way that would keep it from starting if its a dud? Any help as to best things to start with would be much appreciated! I'm still in the learning stages.

 

AS far as I understand it, Starting is controlled by the ICM and it doesn't use any sensor inputs, just the distributor timing pulse. Once RPM's exceed 150 (I think) then it hands over control to the ECM.

Check for spark, check for fuel pressure, and check for injector pulse. If you have all those start looking for something letting air in, like a stuck open throttle body plate, vacuum leak.

I'm wondering if you had some water in the tank or fuel lines and it froze solid and is blocking fuel flow now.

 

Thanks, what is the best way to test for injector pulse? I've seen widely ranging suggestions on the web.

 

Is the fuel pump running? Turn the key on and then off, and you should hear it run for a couple seconds. If it isn't running, check the fuel pump cutoff switch in the passenger footwell (I think that is where it is located.) Push the little white reset button and try again.

 

i couldn't hear the pump when trying it by myself but I am going to get a helper this weekend to try it while I get closer to the pump to listen. I already tried resetting the inertia switch - nothing happened. Thanks.

 

Check the fuel pump cutoff switch and it is called the Inertia Switch.
Push down on the button on top.

Inertia Switch:


/

 

yeah I've already pushed the button down/up. On mine the button is enclosed and there's just a little window to get a small screwdriver into to pry it up and then down again. I haven't checked it otherwise, I've read on some posts about bypassing it in case its the switch that goes but those people seemed to have had problems with their car stopping while running. This is the first time it hasn't started on me since replacing starter/battery/solenoid. Thanks.

 

Make sure all the small wire with rings were put back on the battery side of the starter solenoid.