Im looking into buying a 1994 cherokee.
automatic trans 4 door 4.0L

the owner doesn't seem to know much of anything mechanically.
he believes the fuel pump needs replacement.

the jeep was running and driving about a week ago.
currently it will start and sputter.

Im a college kid looking to build one, but i dont have tons of money right now.
i dont wanna buy this jeep and install the new fuel pump then find out thats not the problem.

any other common problems besides the fuel pump?

also the fuel pump is replaceable without jacks or dropping the tank right?

or any other ideas anybodies got?
thanks guys!

 

Spray some starting fluid in it and see if it will run nicer. Also check the fuel pressure with a gauge. Pre97 you don't have to drop the tank.

 

^^This is a good place to start^^
Also make sure that it has a good strong blue spark.

 

Well, you've got the right idea. Too many come on here and start asking what part to replace.

Test first, THEN replace.

You can test the fuel pressure pretty easily. Some auto parts chains (Autozone, Advance Auto) have a rental program for tools. Basically, you buy the tool, then take it back for a full refund. No time limit.

So, go get yourself a fuel pressure gauge, search on here for how to use it, and test your way to an answer.

As for your original question:



Is fuel pump failure a common issue for a 94?


At 20 years old, if that pump hasn't failed, it's due!

 

It's pretty easy to get a good idea if the fuel pump is the issue here or not.

Get a fuel pressure gauge. They can be rented inexpensively at many parts stores; call around for availability. Hook up the gauge to the schrader valve on the fuel rail under the hood; looks like the valve stem on a tire.

For a 94, you should have approximately 31 psi. Then disconnect the vacuum line leading to the fuel pressure regulator (be sure that vacuum line is NOT wet with fuel) and the pressure should jump to approximately 39 psi. A half hour of testing will tell you a lot. The owner should not have any objections to this. If they do, walk away.

Anytime you buy a vehicle that doesn't run well, that absolutely, positively reduces the value of that vehicle! Substantially. What is the asking price? It may very well be that the owner doesn't know much about vehicles, but sometimes they know more than they are letting on..........you don't want to buy somebody else's problem. Never trust the diagnosis of the owner. Unless you can truly "road test" any vehicle, you better be getting one heck of a bargain in the event you have to put a bunch of money into it.

There are lots of XJs out there. Don't fall in love with the first one you look at.

 

could be something as simple as a clogged fuel filter?

 

When you say "sputter", do you mean that it starts then sputters and dies, or do you mean that it starts and continues to run unevenly?

If it sputters and dies, will it start back up immediately?

I believe the fuel filter is the same as the '93 which is very easy to change out.

 

does the 94 have a carburetor or fuel injectors?
what about a 99? or all they all one of the other?

 

I know the 99 is fuel injected. Not sure about the 94 though.

 

The 4.0 was never carbed from the factory.

 

Injected. Ignition is standard coil & distributor setup.

 

The sputtering could be lack of fuel or even not enough spark.Like said test the fuel pressure at the engine,That will tell you ifs a fuel problem or is it a spark problem.Just remember its a used jeep and some people out there never do a lick of maintenance tell it won't run at all.