1990 F150 inline 6 4.9 liter cranks but won't start
#1
08-31-2016, 12:40 AM
1990 F150 inline 6 4.9 liter cranks but won't start
Having problems with my 1990 F150. So here's the deal, the engine cranks and is getting fuel and getting a spark but will not start. My uncle and I changed the TPS sensor and made sure that the inline 6 firing order is correct at 1-5-3-6-2-4. This is where we get stuck. Not sure what else to check? Oh and it tries to start when using starting fluid but doesn't fully catch. I read on a different thread that the engine control module could be bad so I started to pull it until i decided to stop and post a thread here. Does anyone else have any idea what to check for?
Last edited by Ricky.J; 08-31-2016 at 12:43 AM.
#4
09-01-2016, 06:28 AM
OK , now we have some idea where to start.
Not knowing the information level of the person that changed the wires some folks just feel you plug a wire into the cap and connect it and that should work, well if you did that one at a time it probably would.
Before doing anything , look at the direction the rotor turns when you crank over the engine. It will be either clockwise or counterclockwise.
There is a TDC (top dead center ) mark on the crank pulley that should line up with a pointer just over the crank pulley. When those two line up the #1 piston should be at top dead center. The way to confirm this is to remove the #1 plug , crank the engine over and you will hear/feel the compression coming out of the spark plug hole. When you start to feel the pressure start coming out of the hole the cyl is coming up on the compression stroke . Stop using the starter and turn the engine over by hand in the same direction until the TDC mark on the pulley and the pointer line up. Then remove the dist cap and see where the rotor is pointing . Your # 1 spark plug wire should be at that position of the cap. NOW , going in the direction the rotor turns start placing the plug wires in that direction of the firing order.
Not knowing the information level of the person that changed the wires some folks just feel you plug a wire into the cap and connect it and that should work, well if you did that one at a time it probably would.
Before doing anything , look at the direction the rotor turns when you crank over the engine. It will be either clockwise or counterclockwise.
There is a TDC (top dead center ) mark on the crank pulley that should line up with a pointer just over the crank pulley. When those two line up the #1 piston should be at top dead center. The way to confirm this is to remove the #1 plug , crank the engine over and you will hear/feel the compression coming out of the spark plug hole. When you start to feel the pressure start coming out of the hole the cyl is coming up on the compression stroke . Stop using the starter and turn the engine over by hand in the same direction until the TDC mark on the pulley and the pointer line up. Then remove the dist cap and see where the rotor is pointing . Your # 1 spark plug wire should be at that position of the cap. NOW , going in the direction the rotor turns start placing the plug wires in that direction of the firing order.
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