I have a 1990 with a 300. my engine quit running a week ago. i put new plugs. but it didnt help. is it the distributer or the emissions?
thanks

 

 

Hi, do you have any spark? That's a good place to start, that is asuming the engine turns over. If there is no spark but it turns over check the following and not necessarily in this order.
1. Bad coil -- be careful this can give you a nasty jolt if you grab the coil lead.
2. TFI Module on the side of the distributor. The wiring harness plugs in to it on the distributor. This will have to be removed to test it. there are 4 recessed screws on the module that have to be removed and there is a special thin walled socket sold in all auto stores for $5 that gets in there. If you remove it remove the screws and tip the bottom of the module away from the distributor slightly and pull STRAIGHT DOWN . The module has three brass male spade connectors on it that point straight up and connect into the connector in the distributor. Some auto parts stores I believe can check this module for you.
3. Distributor cap and rotor and distributor to coil wiring.
4. Heres one not many people know about. The EEC Relay ( Electronic Engine Control Relay) this supplies power to the computer. If the contacts on this relay are bad the engine will turn but will not start.:-( It is on the drivers side inner fender pannel near the wire harness connectors it is a metal relay about one inch square and 7/8 inch thick. If you find it give it a couple of raps with a screw driver and see if it does anything. You can test it with a volt meter to see if there is any output to the computer, should be battery voltage. Then one on my 90 was full of water and still worked some times the other times the engine would die or not start. My 93 Ford car had he same problem wouldn't start intermitently.

You may also have a fuel problem. You will need to test the fuel pressure and thusly the pump "s" with a gauge connected to the schrader fitting (looks like a tire valve)on the fuel rail ( be careful let the pressure out into a rag first ). Here's one to look at. You haven't had an accident with the truck or run into something really hard have you?? These trucks have an emergency fuel pump shut off that you have to reset by hand if you hit somthing hard enough.
On F-Series the switch is on the far left part of the toe-board, near the parking brake assembly.:-staun
So you have some detective work to do-- Find out if you have spark and we can go from there.

Bob /stractor

 

Stractor, you covered it all quite well. I appreciate the review.

 

It turned out to be the Fuel filter and the timing was off.
thanks