are these symptoms of a leaking fuel injector?

[bhawk]

94 ranger, 4.0 engine.
We occasionally get a no start condition when the engine is warm. It always starts fine when the engine is dead cold. It also seems to start fine if you let a hot engine sit for an hour or more. However, recently the engine has failed to fire when we turn off a hot engine for about 10-20 minutes.
I checked spark during two of the no start conditions. Both times had lots of spark as tested by my timing lite on one of the plug wires. Each time it wouldn't start we noticed that when it did eventually fire up, usually after we depressed the gas pedal to the floor for a few seconds, we could smell lots of unburned gas. When it fired up it would chug for a bit and then clean itself up. Seemed like a classic case of flooding like on an old carburetor car.
One other test I ran. Fuel pressure is fine, around 32, when the engine is running. Sometimes the pressure holds at 32 when the engine is shut down for some hours. Once it held that pressure overnight. But on my last test, around the time of the last no start incident, fuel pressure has been dropping to 0 quickly after turning off the engine.
The engine has never failed to start when you turn off a hot engine and restart it within a few minutes, say at the gas pumps. It seems it doesn't like to start after a 5-20 minute turn off. I'm thinking a fuel injector is leaking gas into the lower intake and flooding us????

 

[tbirdsps]

Sorry that I'm no help on this one but make sure you don't have gas in the oil. That could be much worse. Pull the dip stick and take a good sniff. If it's gassy you need to not only change it but determine what's going on. Unrelated but I've read about the 6 liter diesels having problems with stuck injectors to the point of destroying the engine.

You could try pulling the plugs and seeing if one or more a black indicating rich on that or those cylinders.

Just a thought from a 2.3 guy.

 

[Beanmachine7000]

94 ranger, 4.0 engine.
We occasionally get a no start condition when the engine is warm. It always starts fine when the engine is dead cold. It also seems to start fine if you let a hot engine sit for an hour or more. However, recently the engine has failed to fire when we turn off a hot engine for about 10-20 minutes.
I checked spark during two of the no start conditions. Both times had lots of spark as tested by my timing lite on one of the plug wires. Each time it wouldn't start we noticed that when it did eventually fire up, usually after we depressed the gas pedal to the floor for a few seconds, we could smell lots of unburned gas. When it fired up it would chug for a bit and then clean itself up. Seemed like a classic case of flooding like on an old carburetor car.
One other test I ran. Fuel pressure is fine, around 32, when the engine is running. Sometimes the pressure holds at 32 when the engine is shut down for some hours. Once it held that pressure overnight. But on my last test, around the time of the last no start incident, fuel pressure has been dropping to 0 quickly after turning off the engine.
The engine has never failed to start when you turn off a hot engine and restart it within a few minutes, say at the gas pumps. It seems it doesn't like to start after a 5-20 minute turn off. I'm thinking a fuel injector is leaking gas into the lower intake and flooding us????

Sounds highly highly likely...

 

[bhawk]

Assuming an injector is leaking fuel into the intake, how do I determine which one is at fault?

 

[Earl43P]

You might see evidence on the spark plug; one should look significantly different than the rest.

Here's how to clean injectors: http://www.fordfuelinjection.com/?p=82

 

[kimcrwbr1]

You can try cleaning the throttle body also my jeep did the same thing and figured ou the throttle shaft is getting loose and closing too far so I turned the throttle stop to open the butterfly a little and it helps alot. If you adjust the throttle stop you will need to reset the computer so it knows when the throttle plate is all the way closed.