99 mountaineer will not accelerate

[mountaineer99]

99 mountaineer 4.0l sohc will idle fine when I step on the gas it wants to die out. when I pump the gas it will sometinme reach 2000 rpm.
What could be the problem?

 

[BrianDye]

Hmm
Have you checked any of the fuel system yet?
Could be as simple as a fuel filter....

 

[kindred4x]

Do you have a check engine light or flashing OD light?

 

[mountaineer99]

99 mountaineer no accelleration

The gas filter is probably about 4 months old. I will change it again. How can the throttle body be checked or the fuel pump. I thought if the fuel pump was bad I would not be able to start it at all. I have no engine light on or OD light.
The way it running it seems to be starving for gas when you press on the gas.
I had someone tell me to replace the coil pack could that be a possibility? The truck seems to run fine at idle.

 

[mountaineer99]

99 mountaineer bg down on accelleration

I changed the gas filter and the same problem. I turned the key on with the line on the discharge of the filter off and saw gas sparying out when the key is turned on for a few second then I think the pump shuts off until running.
I think I know the fuel pump is fine. What could the problem be?

 

[kindred4x]

I don't know much about the sohc because i own a ohv. Obviously the fuel pump is running if it sprayed fuel. Check the throttle cable to the throttle body and see if it is opening the butterfly plate, a bad throttle position sensor could also cause the same problems

 

[mountaineer99]

1999 mountaineer 4.0l v6

I replaced the throttlr position sensor today and I still have the same problem.
I still think it is something with the fuel pump I am going to try to check the psi somehow. I do not want to go thru all the work to have the same problem.

 

[hworksinc]

yeah - you need to get a gauge and actually check the fuel pressure. It may be a problem with the fuel pressure regulator as well. Monitor the fuel pressure while the engine is running to see if it drops off.

 

[mountaineer99]

1999 mountaineer no accelleration

I changed out the fuel pump and the whole assembly in the tank. I still have the same problem. I now think it must be the fuel injectors. I thought it was the fuel pump because how the problem occurred so suddenly. The engine was running fine then I started off from a stree light and the engine boggged down. I did not have the correct end to check the fuel pressure so I took a chance.
Is there a way to check the injectors?
I have the 4.0l v6 and am not sure what else it could be.
Any help
Thanks