1987 Cherokee 4.0L. The thing won't start on fresh gas. It runs great on starting fluid. I have flushed all the fuel lines and verified that the fuel pump is supplying fuel to the rail. The injectors were removed and soaked in cleaner and reinstalled. The vehicle was cranked over with the rail out and I saw the injectors squirting fuel. I tried to crimp off the fuel return line to make sure that there is fuel pressure and didn't knotice a change. If cranked long enough, the motor fires alive, dies and cranks some more. It will also back fire occasionally. Giving it some throttle imput doesn't help and the motor won't even try and start. Crankshaft postion sensor looks new and shinny(probably was replaced by PO in that last few years.

I have spark, compression, and fuel supplied. Fuel pressure could be low and I don't have the tool to check the pressure. Any other way to check it?

Is my camsahft position sensor/coil, (what ever its called) gone bad and not injecting fuel at the right time? Fuel pressure low? ICU box junk? C101 connections bad? Where can i get cheap/affordable parts?

This Jeep's got me stumped. It sat for over a year and i'm trying to get it running again to tought truck it. The thing ran great with lots of power before it was parked over a year ago. Thanks in advanced.

 

Fresh Gas ?

 

Yea, also known as fuel that is new. Becuase the vehicle has sat for over a year I pumped out all the 'Bad' gas and put new fuel in.

 

Fuel filter clear ?

 

There is no filter as of now. It was removed and replaced by a rubber hose. I removed the supply line at the rail and turned the key; Fuel came rushing out as an expected result.

 

The sensor in the distributor has nothing to do with your problem. Why don't you have a fuel filter?

 

Beg or borrow a fuel pressure gauge. If it runs fine on starting fluid, you have a fuel delivery issue. Fuel pressure is the first check you should run.
Autozone and the like normally rent them out.

 

I removed the return line from fuel pressure regulator and cycled the key a few times and could not get any fuel to come out of the regulator.

I removed the fuel pressure regulator and tested it with a air hose. The regulator opened when the supplied air pressure was above 40psi. Anything below 40 psi the fuel pressure regulator would close and not let the air pass.

So the question is why will the fuel pump send fuel but not build pressure. What is the cheapest way to fix it. This jeep is for tough truck events so i'm not looking to dump a lot of money into it Inline fuel pump? I only need .75 gpm.

 

Assuming it has good power supplied to it, it's probably just worn out.