My 88 jeep cherokee starts up and idles fine but when you hit the throttle it dies out and sometimes back fires out of the throttle body. The jeep has been sitting for a year.

 

Could the fuel filter be clogged and starving it for fuel?

 

I'd suspect the TPS (throttle position sensor).

When you hit the throttle, it gets a lot of air, the TPS needs to signal the computer to add fuel, else the mixture is too lean and won't fire.

Try applying the throttle slowly rather than nail it, does that help?

 

That, old gas, or a weak fuel pump are possibilities.

 

The fuel pump was changed a month before I parked it. I tryed putting new gas in it.

 

Could be alot of things. Popping through the intake is usually lack of fuel.

How are the plug wires? Rodents been munching on them?

 

Wires look good. They were replaced about 6 months before I parked it. I ended up getting a 98 so I was driving it. But now I want my old one back haha

 

So I changed my fuel filter and that still didnt help.

 

Need to do a fuel pressure test. If the pump you installed was Airtex, it could be bad.

 

Im not getting good pressure when I turn the key on. When it first starts it has about 35 psi then it drops to zero and the jeep wants to stall out

 

You need a fuel pump, Marc.

 

Changed fuel pump now I have fuel pressure but still have the same problem

 

What kind of pressure now?

 

Well I got it to run. I ran a hot wire to the fuel pump now it runs. It has a small miss but it runs

 

Ever jump across the fuel pump ballast resistor?