1988 Dodge P/U with a 318. Getting fuel to carb but only when I try and start it, no fuel at all when I just turn the key to activate pump. Not a mechanic by no means but have been following diagrams and so forth. Not sure if it is pump or fuel regulator any help would be beneficial. Thanks

was fuel filter replaced --relay--and test pump for proper install and new doesnt mean free from defects

just had a similar prob with my 89 ram charger with a 318 tbi i had changed plugs battery checked distributor and rotor and a host of other things because it would crank but not turn on finally took it in to shop ended up being the FUEL RELAY paid 90 bucks but that was mostly labor figuring why it wouldn't start ..i would check there before changing a fuel pump could b a clogged FUEL FILTER or INJECTOR hope this helps

Fuel injected on a 1988 model, no carb used.
Is the fuel pump running when you turn the key on ?

If you can spray carb cleaner in the carb then you have either a fuel supply problem or fuel delivery problem. Check your fuel pressure and make sure it is in spec. Then check the spray in the carb spray.

sound like you have either a clogged fuel filter or a bad fuel pump
start with the fuel filter first keep it simple first
if that don't work for you then pull your fuel line off and cycle the key and see if the pump is putting out fuel
if you don't get fuel then change the fuel pump
hope I could help
leave some feedback if you could
good luck

Replace Injectors they a leaking

Try putting a little gas in the top of the carb. Then try to start, if it starts then it's a fuel problem, clogged filter, lines, carb or fuel pump. If it doen't start with the gas then check for spark, disconnect a spark plug wire put on a spare spark plug, ground plug threads to motor and have someone turn over motor. You should see a spark between plug and electrode. Also you could check compression of engine, rings could be siezed and no compression will mean no start. If low or no compression, pour wd-40 or other lubricant into spark plug holes and let sit for a couple of days. Hopefully that would unsieze rings.

Check all of the fuel lines very carefully for breaks or cracks in the fuel lines, especially between the fuel tank and the fuel pump.

If the fuel lines are all in good condition then you can safely assume that the problem is in the fuel pump and you will need to replace it. (If the fuel pump is in really bad shape the engine oil on the end of the engine oil dip-stick will smell like fuel)

The filter is external. Located on the passenger side frame rail, about 4-5 ft from the tank. round, metal (or if previously replaced-- might be plastic). Are you sure you have a carb? 1988 models were throttle body type fuel injection. If it is TBI, you may not be getting power to the internal fuel pump. Are you seeing a fault code (the check engine light flashing)?

Check to make sure you are getting fuel pressure. Can you hear the fuel pump come on? Will it start with carb cleaner being sprayed in the carb (watch for back fire)? If it will start with carb spray and you can not hear the pump its the pump. Try to get it to go like a old stuck starter. Have someone turn the key and use your fist to bang the fuel tank sometimes that will get it to go. Sounds like you need a pump.