Monday, October 24, 2011

How to properly troubleshoot to find correct problem?

I just bought a 1990 ford f150 2 days ago. its in very nice condition, been running well. i bought it from a friend so i know its a great truck no doubt. heres the thing. yesterday i washed the truck exterior then some under the hood. after that i started it just fine and parked it. later on i drove it home for 20 miles. it did cut off one time and was a little hard to get back going. it felt like it had water in the cap and rotor. it finally started up and kept running. it was so cold out and i was ready to leave. this morning i started the truck up to let it run and warm the heater. after 10 minutes i heard it shut off. after i got my boots on and all ready to leave for work. i restarted the truck with a small hesitation. i drove it less than a 1/4 mile and it shut off and tried all day and still hasnt started.

i checked the cap and rotor.....i was thinking it had water from washing day before. looked in and all was dry. i replaced the cap and rotor anyways. then also changed 8 spark plugs, checked for firing and all seems good. checked fire at both ends of coil wire, rotor end and coil. checked fire at #1 spark plug, very good. rotor is spinning, so distributor is not broke. i then knew it was firing good. so then wondered about fuel.....it has a full tank of fuel. i never could hear a fuel pump........i looked for a fuel pump on the frame and only fuel filter there, so im thinking the fuel pump is in the fuel tank..? i opened fuel pressure bleed on engine and no fuel there, either with key on and cranking engine. i removed hose off fuel filter and only a few drops of gas fell out. had friend turn key on to see if fuel pumped out and still no fuel, so had friend crank engine and still no gas................so, how do i know problem is with fuel pump? it may be electrical/ relay/ solenoid? i havent checked wiring to fuel pump yet.......is fuel pump in the tank and how to change? 1990 f150, 5.0 fuel injected auto, all info is greatly appreciatedHow to properly troubleshoot to find correct problem?the pump is in the tank and the tank has to be dropped to change it...dont worry its not a hard job its fairly simple.. check your fuses and relays under the hood and in the cab as well for anything involving fuel... if all is well with no blown fuses or relays id say its probably a fuel pump sometimes they work well then go on kicks where they work every now and again towards the end of their life.... you can find anything you need to know roughly about taking the truck apart in a Haynes manual... you can get the one for your truck at autozone or onlineHow to properly troubleshoot to find correct problem?try resetting the inertia switch first, it's in the owners manual.. then check for voltage at the pump, if you have voltage, put no action, replace it..