My Truck Wont Start.
08-01-2014, 11:08 AM
#41
Senior Member
Well, one thing about that MAP sensor is to make sure the vacuum hose that runs to it is 100% clear. When I rebuilt my engine, I had all kinds of problems and it was the MAP sensor vacuum hose being stopped up. Simple, but it was something that took me forever to figure out. Just blow in the hose to make sure it's clear is what I'm saying.
08-01-2014, 12:13 PM
#42
Hi-Rev Motorsports
stupid question but did you check fuses? you said that you didnt unhook the battery so it is possible you blew a fuse in the process.
if you have a timing light hook it to #1 and unplug the SPOUT connector and have someone crank the engine and make sure it is firing at 10° BTDC.
I always clean the tab and the balancer and paint a faint white mark on both so the light hits it and reflects.... this way there is no second guessing.
there is only 3 things needed to make an engine run.... Fuel, Air and Spark....
check cranking timing...
Check Injector pulsing...
open throttle body a tiny bit.... you'll have air.
MAP, TPS and a few other sensors can alter injector pulses....if you have pulses then injectors are pulsing but that doesnt mean you have fuel... Fuel pressure test
to check if injectors are in fact spraying do a FPT then pull the fuel pump fuse and crank.... if pressure drops instantly as soon as the engine cranks it is spraying... if it doesn't? it's not!
EDIT: beings you sprayed Starter Fluid in the intake and it didnt attempt to fire something tells me you either have a weak spark issue or the timing is off....
there are at most times more than one mark on the balancer....make sure you're using the Skinny mark...
if you have to place a long skinny screw driver in the #1 plug hole and turn the engine by hand and make sure the piston is at TDC.
if you have a timing light hook it to #1 and unplug the SPOUT connector and have someone crank the engine and make sure it is firing at 10° BTDC.
I always clean the tab and the balancer and paint a faint white mark on both so the light hits it and reflects.... this way there is no second guessing.
there is only 3 things needed to make an engine run.... Fuel, Air and Spark....
check cranking timing...
Check Injector pulsing...
open throttle body a tiny bit.... you'll have air.
MAP, TPS and a few other sensors can alter injector pulses....if you have pulses then injectors are pulsing but that doesnt mean you have fuel... Fuel pressure test
to check if injectors are in fact spraying do a FPT then pull the fuel pump fuse and crank.... if pressure drops instantly as soon as the engine cranks it is spraying... if it doesn't? it's not!
EDIT: beings you sprayed Starter Fluid in the intake and it didnt attempt to fire something tells me you either have a weak spark issue or the timing is off....
there are at most times more than one mark on the balancer....make sure you're using the Skinny mark...
if you have to place a long skinny screw driver in the #1 plug hole and turn the engine by hand and make sure the piston is at TDC.
Last edited by dr_bowtie; 08-01-2014 at 12:16 PM.
08-01-2014, 12:56 PM
#43
I
Thread Starter
We checked all the fuses in the fuse box, they all look good. I have a timing light, I'll check to see if its firing correctly. Also by FPT I assume you mean fuel pressure test?
08-01-2014, 03:00 PM
#45
I
Thread Starter
I tried turning the rotor 180° thinking maybe it was timed to the exhaust stroke, and tried starting it. It popped/backfired after I cranked it for a little bit. So I moved it back to where it was and still no start. Does backfiring indicate I am indeed getting spark and fuel?
Last edited by tanman90; 08-01-2014 at 03:13 PM.
08-01-2014, 11:42 PM
#47
I
Thread Starter
I work tomorrow morning so it'll be tomorrow afternoon until I can check it. If the timing checks out ok, what could cause a weak spark? It has an msd coil cap&rotor, ford racing 9mm wires, and motorcraft copper cores, all less than a year old.
08-02-2014, 09:54 AM
#48
Hi-Rev Motorsports
bad connections, weak ignition module.
here is what i would do....
line up the #1 again and put the mark on 10° as you have pictured. Pull the rotor and look at the timer/core. Line up the magnetic pickup with the timer core tab. thats when it fires.... not where the rotor always points.
here is what i would do....
line up the #1 again and put the mark on 10° as you have pictured. Pull the rotor and look at the timer/core. Line up the magnetic pickup with the timer core tab. thats when it fires.... not where the rotor always points.
Last edited by dr_bowtie; 08-02-2014 at 09:57 AM.
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tanman90 (08-02-2014)
08-02-2014, 11:44 AM
#49
I
Thread Starter
bad connections, weak ignition module.
here is what i would do....
line up the #1 again and put the mark on 10° as you have pictured. Pull the rotor and look at the timer/core. Line up the magnetic pickup with the timer core tab. thats when it fires.... not where the rotor always points.
here is what i would do....
line up the #1 again and put the mark on 10° as you have pictured. Pull the rotor and look at the timer/core. Line up the magnetic pickup with the timer core tab. thats when it fires.... not where the rotor always points.