jeep_newby

Picked up a 93 Jeep Cherokee (4.0 6-cyl) in great condition. However, it sat in a garage the last 7 years so I drained the fuel. Then I tested fuel pressure at the fuel rail. Came in at 35 PSI when in "on" position, ~40 PSI while turning over.

I emptied the fuel tank, flushed the fuel lines, and added ~ 1 gallon of new fuel. Then, to rule out bad fuel in the line I used the last fuel flushed throught the fuel rail to start the car by pouring a little into the intake. It started the car just fine but it still won't run on it's own.

Can't figure out what to check next....

Thinking maybe camshaft position sensor (can't figure out where the heck it is) or crankshaft position sensor (want to rule out former before changing that). Or maybe whatever tells the injectors to open?

I have a multimeter and basic tools.

Any ideas what steps I should take next?

EZEARL

Have you cleaned the throttle body and IAC?
http://cruiser54.com/?p=60

jeep_newby

Yes. Checked/cleaned both.

I should have said it will only start with starter fluid or gas in the intake. Won't start on its own.

Not sure if that helps

jeep_newby

Yes. Checked/cleaned both.

I should have said it will only start with starter fluid or gas in the intake. Won't start on its own.

Not sure if that helps

Edit

Idunno

If you're manually feeding fuel into the intake and it fires up you're getting spark. Does it run long enough to get an idea if it's running smooth before it dies? If you're getting spark then it sounds like it's fuel-starved. I suppose you've checked for pressure on the rail? To my knowledge of this system if you've got spark then the computer is seeing good (normal) feedback from the sensors and allowing ignition. It's odd that the plugs fire but the injectors (seemingly) have been disabled.

things

Certainly check the fuel pressure as stated above and I would add a few gallons more of gas for sure.One gallon in a cleaned tank seems hardly enough. Then check again.

Listen at the open gas cap for the fuel pump working if no fuel pressure. Then check the fuel pressure relay.

lawsoncl

Are the injectors clicking? If not, then maybe ASD relay?

jeep_newby

Yes, it runs smooth when fuel is added via the throttle body.

Definitely seems fuel starved to me.

Pressure on the trail is ~35 when key is turned to on. About 40psi when I try to start by turning the key.

Any idea what might cause all the injectors to not work? I get off one or two are bad, but all of them seems odd. Maybe not since it sat for 7 years...

jeep_newby

Will add more fuel tomorrow and report my findings. Fuel pump is definitely turning on and creating fuel pressure in the rail.

Already replaced the fuel pump relay. Is there another relay I should check in addition to that?

jeep_newby

Will check tomorrow. Not sure I've ever heard an injector click before. If not, I'll replace the ASD relay.

doublechaz

Some vehicles the injectors click so loud people think there is something wrong (Subaru). Others you can't really hear it without a tool. The 4.0 Jeep seems to be on the quieter side. A stethoscope on each injector would be ideal, but without that you can use a long screwdriver or other long rod. One end pressed to the injector, the handle pressed to the bone behind your ear. Of course you have to be careful not to rip your hand off in the moving engine parts and to not impale yourself on the tool.

jeep_newby

Added 2 more gallons of fuel.

Fuel pump is still turning on. Replaced fuel pump relay and auto shut down relay.

Is there another fuel "pressure" relay?

jeep_newby

Injectors aren't clicking...

So I replaced the ASD relay (and the fuel pump relay).

vadim

Are the injectors getting the pulse? That can be checked with a noid light. If they are, they are probably stuck closed due to 7 years of sitting.

jeep_newby

Injectors are getting a pulse. On to fixing/replacing injectors...

Is there a way to verify the existing injectors are stuck or get them unstuck?