got spark, fuel, no start, WTF!

[Trevrok]

Hello, got an 85 f-150 FI-302, started running badly, no power, today it won't start. I have spark, fuel pump makes noise like it pressures up, tried both tanks, changed fuel filter, still the dang thing won't fire up. has been a dependable daily driver. anyone got any ideas? THANKS!

[way2old]

You need to check fuel pressure on the fuel rail in engine compartment. The pump can be powering up, but not have enough pressure to start vehicle. Spray some carburetor cleaner into the intake and see if it tries to start. If it starts and dies, either the pump is weak(why the pressure needs checked) or the injectors are not opening. Let us know what you find.

[Trevrok]

Thank you, I'll try it. seems cheaper and easier to just replace the fuel pump since I don't have a fuel pressure guage and have no clue how to use one, this is my first F.I. truck. the pump is only 59 bucks and easy to access. Great advise, THANKS!

[Trevrok]

Ok, replaced the fuel pump, popped for the hundred dollar one, and it still wont fire up. is there any sensor or relay that would cause this?

[way2old]

Ok Trevrok. You needed to check pressures instead of replacing pump. These are bad about the TFI(ignition module) going out. You need to check for how much and quality of spark that it is producing before you start throwing anymore parts at it. You can purchase a calibrated spark checker for around 10 dollars or so. You plug a wire on it, set the distance, and ground the tool. If spark jumps about .060 on the little tool, you probably have enough spark to start. If not, then look closely at the module. Test first.

Just came to mind there is an EEC relay under the hood. Check all of them to be sure they are good.