Throttle body when you shut off engine it is hard to start there is fuel leaking in to the throttle body

If your 96 Ford F250 starts up and then immediately shuts off, there could be several potential causes. Here are some things you can check:

1. Fuel delivery: Make sure the fuel pump is working and delivering fuel to the engine. You can check the fuel pressure with a fuel pressure gauge to see if it is within the proper range.
2. Ignition: The ignition system is responsible for starting the engine. Check the spark plugs, spark plug wires, and ignition coil to see if they are in good condition.
3. Engine management: The engine management system controls the fuel and air mixture going into the engine. Check the mass air flow sensor and the throttle position sensor to see if they are working properly.
4. Throttle control: Check the throttle cable to make sure it is moving freely and that the throttle body is clean.
5. Engine vacuum: Check the engine vacuum hoses to make sure they are connected and not leaking.
6. Security system: Some Ford trucks are equipped with a security system that can prevent the engine from starting if it doesn't recognize the key.

If you're unable to locate the problem or if the problem persists, it's best to take your vehicle to a qualified mechanic to diagnose and repair the issue.

Throttle body injection I assume , watch butterfly on injector and c if it injects fuel , if it starts w ether but shuts off its still not getting fuel into cylenders and since your fuel pressure to engine is normal , the problem is in the throttle body or injection ..possible electrical ...if for some reason u still have a carbureted engine hit me back up it could be sumin diff

89 has the old stand alone spark distributor.
the ECU is spark free, (no player here)
so here is the list for this engine 1.3 or 1.6L
the 1.3 has a carb. (last one) and is NOT EFI ,
you never said which engine it has. so ill guess at the 1.6L
This engine will have hard starting for the fooling reasons.
we dont guess at it we just do the tests.

• Bad fuel.
• Never tunedup this decade or every 60,000 miles per opr. guide.
• low engine compression 150 good, if all are very low the cam timing belt slipped., (they all do , ignored) and is 60k service point.
• CEL dead key on, bad ECU or lamp bad.
• CEL glowing running, its telling you what is wrong, get the flash codes (DTC's)
• Too high fuel pressure. (bad regulator in front of TB)
• ECT bad. the 2 pin engine coolant temp sensor is bad. test it.
• The injector leaks in the throttle body (look with eyes)
• You find that adding 5-10% throttle cranking makes it more easy that is a bad, IAC valve, the valve at the base of the throttle body is stuck closed and kills all cold start air supply. making cold starts very hard, unless tricked with right foot. yes?
• when any gas engine fails to start cold, i check for too much or too little starting fuel. and for very good spark.
• Good engine, good spark the good fueling, there are tests for each, ASK?

do you have a small propane torch? or a can or throttle body cleaner or anything similar? Spray the propane(Just the gas, do nit light it) or throttle body clean, slowly around the engine and if there is a vacuum leak the rpm will rise when the propane fumes or throttle body spray gets sucked in and you know it will be in that area. Anywhere from the front of the motor to the sides to all the way behind, it might not be a vacuum hose, could be an intake manifold leak. Smelling fuel when shutting off can be a different problem all together.

You must have a leak or one of the lines are clogged. The reason it stays running when your on the gas is because it keeps the fuel pressure up. Then when it shuts off it loses all pressure in the line and the pump cant handle the initial start with the leak in the line.

I'm guessing your mixture is too lean and it's possibly running a bit rough and there isn't enough fuel getting to the engine. A rich mixture is too much fuel, but that error is usually related to O2 sensors. It might be the O2, but 'trim malfunction,' you're looking at a vacuum leak. Check the oil separator valve then the throttle body gasket and then the intakes. Most likely a vacuum leak and the throttle body, oil separator and intake are the most likely. Run your hand around the bottom of the throttle body and oil separator, if it's greasy/oily there, there's a leak.

If there is no leak, test the MAF sensors...they might need cleaning, and in a worst case scenario, might need replacing.

check your map sensor as well as the range on your tps/ throttle postion sensor and your throttle body gaskets sometimes that engine will get a air leak that corrupts the vacumn necessary to operate the fuel rail which in turn will shut the fuel off at a idle

Take a can of parts cleaner and spay it around the throttle body to check for a leak and if it is not there then sprat it around were your vacum hoses are connected to the engine that is how i check for vacum leaks.

, pull a plug wire and ground it to the engine body and check for spark. if spark then
check your fuel system pressure, fuel pump

get your hands on a fuel pressure tester.. this will tell u if u are losing fuel pressure between starts... those 4.3 v6's have a big problem with the poppet valve (injector assembly) leaking. causing the engine to flood...and losing pressure to push threw the injector... causing the hard start...but the fuel pump module will also lose pressure as has a check valve to keep that from happening but from time to time they do leak allowing fuel to flow back into the tank...with this pressure tester, have a friend turn the key to on.. after you hear the fuel pump shut off immediately pinch off the two fuel lines going from the tank to engine you can find these right below the driver side door. you will find the fuel filter there which is the pressure hose the other hoseis the return... both rubber hoses that will not be harmed by the vise grips or tools be your choice the other metal line is a vapor line which is not important. after you do pinch the lines off check the fuel pressure if it still drops with no signs of slowing down then the poppet valve is defective...if it does not move then you know it is definitely the fuel pump module (fuel pump assembly)