95 302 won't start after tune up
#1
95 302 won't start after tune up
I have a 95 f150 with a 5.0 I did plugs an wires, along with cap an rotor. I gapped the plugs to .052 I used a wire tester they are getting spark. i only have 20 psi fuel pressure with the key on engine off (cause it won't start.) And the 20 psi only came from cycling the key 3 times an it maxed out right there At the fuel rail. It has a quarter tank of fuel. it's my only vehicle right now an i need any advise. could it be a fuel filter? Or straight to the pump? Please help!
#2
Senior Member
iTrader: (1)
Anything under 30 it won't run. Key on engine off you should have about 40 to 45.
So fuel pressure is probably your problem.
You can try changing the filter - you probably want to do that anyway. It would have to be plugged pretty solid to do that though.
And possibly the fuel pressure regulator (though if it holds 20 psi for a few minutes, that won't likely be the problem).
Most likely though, you're going for a pump.
So fuel pressure is probably your problem.
You can try changing the filter - you probably want to do that anyway. It would have to be plugged pretty solid to do that though.
And possibly the fuel pressure regulator (though if it holds 20 psi for a few minutes, that won't likely be the problem).
Most likely though, you're going for a pump.
#4
I did the 302 HO firing order as specified under the hood. It did start an run before the tune up. I did the pump an now have 40 psi key on engine off still will not start up. It just cranks. when I hit the gas to wide open it starts so sputter like it wants to run but won't start. Could my tps be bad as well?
#5
Senior Member
iTrader: (1)
Starting fluid - 3 second burst into the throttle body, then go turn the key. If it fires, it's a fuel issue.
Yes the TPS could be bad. You also could have bumped the connector while you were doing a tuneup. Check the connection. A faulty tps signal can shut down the injectors, among other things.
To test the signal you need a little multimeter - a $15 cheapy will work fine.
Set the meter to volts dc. black lead goes to battery negative -. red lead goes to the black wire coming off the tps (poke it).
You can leave the engine off, key on. Closed throttle you should have a reading of .9
As you open and close the throttle steadily, the voltage should rise to 4.5 to 5 volts and fall back to .9 as you close the throttle.
Signal should rise and fall steadily, no flat spots.
You have spark, you have fuel pressure, HO firing order is correct for 95, so the next logical thought would be that the injectors aren't opening (I would think).
Yes the TPS could be bad. You also could have bumped the connector while you were doing a tuneup. Check the connection. A faulty tps signal can shut down the injectors, among other things.
To test the signal you need a little multimeter - a $15 cheapy will work fine.
Set the meter to volts dc. black lead goes to battery negative -. red lead goes to the black wire coming off the tps (poke it).
You can leave the engine off, key on. Closed throttle you should have a reading of .9
As you open and close the throttle steadily, the voltage should rise to 4.5 to 5 volts and fall back to .9 as you close the throttle.
Signal should rise and fall steadily, no flat spots.
You have spark, you have fuel pressure, HO firing order is correct for 95, so the next logical thought would be that the injectors aren't opening (I would think).
Last edited by Chris_1; 03-30-2015 at 05:45 PM.