I have a '91 Ranger with a 4.0. It runs really well but it is extremely hard starting. Any suggestions?

 

Sounds like a fuel delivery issue. Other than that it might be a spark plug issue. How do the plugs look?

 

Plugs and fuel filter are new.

 

You may want to take a fuel pressure reading at the fuel rail on the engine. There is a connection on the fuel rail that you can attach a gage to. It has a schrader valve in it (like a tire valve stem). If you are getting low pressure with the key on but the engine not running or with it running, one thing to look at would be the rubber hose that connects the fuel pump to the metal tube inside the gas tank. There are other things to look at before you get into the tank, but this is one possibility that I wanted to let you know about. You could have a good strong pump but if this hose has a small hole in it, it won't let full pressure build up in the system when you want to start it. The first time I ran into this problem was when my 90 Ranger had over 100k on it. Pinhole size leak was all it took. The best way to get at the fuel tank is to remove the bed. Six #55 Torx bolts hold the bed on, with two of them (up by the cab) being longer than the 4 toward the back. They go into large nut plate clips on the frame. Spray them down good a day or two before you start the job with your favorite rusty bolt spray. You can cut the bolts from under the bed if needed and replace them with grade 8 bolts & nuts from your favorite hardware store. Take out the three screws that hold the filler neck to the bed, so it can drop free of the bed as you lift it up. You can keep the fuel cap on so junk won't fall in the filler as you take it off the bed. Take out the tail lights and unthread the tail light wire harness from where it goes through the bed or is held to it, so it will be out of the way when the bed is removed. Two guys or maybe three can lift the bed off and set it behind the truck on horses and you will have a clear access to the top of the tank. The metal lock ring that holds the fuel pump & sender assembly in the tank can be purchased from Ford still. At least a couple of years ago it could when I got one. Might want to clean off the top of the tank around the sender unit so the dirt and other debris won't fall into the tank when you take the sender out. The rubber hose on the pump is only about 3 inches long and held on with a couple of clamps. Once you get the hose replaced you can test the system again before the bed goes on to see if that really was the fix or if you need to look at some other possibilities like the pump itself or the pressure regulator up on the fuel rail. Let us know how it goes.

 

I have a similar problem with my ranger. I tried putting a new iac, cleaning the throttle body, and cleaning the maf sensor. I'll let you know if it helps.